From 0ecb1f4baf8e380b96c61b6fd6b3273fd80b6f16 Mon Sep 17 00:00:00 2001
From: Yuri Sergiichuk <yuri.sergiichuk@teamdev.com>
Date: Fri, 4 Dec 2020 14:14:30 +0200
Subject: [PATCH 01/41] Bump versions.

---
 version.gradle.kts | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/version.gradle.kts b/version.gradle.kts
index 1edf3707d..a2cc7aafa 100644
--- a/version.gradle.kts
+++ b/version.gradle.kts
@@ -18,10 +18,10 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-val spineBaseVersion: String by extra("1.6.13")
-val spineTimeVersion: String by extra("1.6.13")
-val spineCoreVersion: String by extra("1.6.15")
+val spineBaseVersion: String by extra("1.6.16")
+val spineTimeVersion: String by extra("1.6.16")
+val spineCoreVersion: String by extra("1.6.18")
 val spineVersion: String by extra(spineCoreVersion)
 
-val versionToPublish: String by extra("1.6.15")
-val versionToPublishJs: String by extra("1.6.15")
+val versionToPublish: String by extra("1.6.16")
+val versionToPublishJs: String by extra("1.6.16")

From 9d512f4b2c8041ec96d51e154b7e4b0a23a14359 Mon Sep 17 00:00:00 2001
From: Yuri Sergiichuk <yuri.sergiichuk@teamdev.com>
Date: Fri, 4 Dec 2020 14:15:53 +0200
Subject: [PATCH 02/41] Update `config`.

---
 .idea/codeStyles/Project.xml                  |  26 +++-
 .idea/codeStyles/codeStyleConfig.xml          |   2 +-
 .idea/inspectionProfiles/Project_Default.xml  |  33 +----
 .idea/misc.xml                                |  21 ++-
 .../spine/gradle/internal/IncrementGuard.kt   |   6 +-
 .../io/spine/gradle/internal/RunBuild.kt      |  16 +--
 .../kotlin/io/spine/gradle/internal/deps.kt   | 121 +++++++++---------
 config                                        |   2 +-
 8 files changed, 125 insertions(+), 102 deletions(-)

diff --git a/.idea/codeStyles/Project.xml b/.idea/codeStyles/Project.xml
index d1143f766..5a399bd1a 100644
--- a/.idea/codeStyles/Project.xml
+++ b/.idea/codeStyles/Project.xml
@@ -25,6 +25,27 @@
         <ANNO name="org.junit.jupiter.api.Test" />
       </REPEAT_ANNOTATIONS>
     </JavaCodeStyleSettings>
+    <JetCodeStyleSettings>
+      <option name="PACKAGES_TO_USE_STAR_IMPORTS">
+        <value>
+          <package name="java.util" alias="false" withSubpackages="false" />
+          <package name="kotlinx.android.synthetic" alias="false" withSubpackages="false" />
+          <package name="io.ktor" alias="false" withSubpackages="false" />
+        </value>
+      </option>
+      <option name="PACKAGES_IMPORT_LAYOUT">
+        <value>
+          <package name="" alias="false" withSubpackages="true" />
+          <package name="java" alias="false" withSubpackages="false" />
+          <package name="javax" alias="false" withSubpackages="false" />
+          <package name="kotlin" alias="false" withSubpackages="false" />
+          <package name="" alias="true" withSubpackages="true" />
+        </value>
+      </option>
+      <option name="NAME_COUNT_TO_USE_STAR_IMPORT" value="2147483647" />
+      <option name="NAME_COUNT_TO_USE_STAR_IMPORT_FOR_MEMBERS" value="2147483647" />
+      <option name="CODE_STYLE_DEFAULTS" value="KOTLIN_OFFICIAL" />
+    </JetCodeStyleSettings>
     <XML>
       <option name="XML_LEGACY_SETTINGS_IMPORTED" value="true" />
     </XML>
@@ -71,5 +92,8 @@
         </groups>
       </arrangement>
     </codeStyleSettings>
+    <codeStyleSettings language="kotlin">
+      <option name="CODE_STYLE_DEFAULTS" value="KOTLIN_OFFICIAL" />
+    </codeStyleSettings>
   </code_scheme>
-</component>
\ No newline at end of file
+</component>
diff --git a/.idea/codeStyles/codeStyleConfig.xml b/.idea/codeStyles/codeStyleConfig.xml
index 79ee123c2..0f7bc519d 100644
--- a/.idea/codeStyles/codeStyleConfig.xml
+++ b/.idea/codeStyles/codeStyleConfig.xml
@@ -2,4 +2,4 @@
   <state>
     <option name="USE_PER_PROJECT_SETTINGS" value="true" />
   </state>
-</component>
\ No newline at end of file
+</component>
diff --git a/.idea/inspectionProfiles/Project_Default.xml b/.idea/inspectionProfiles/Project_Default.xml
index 03926c8cc..44917ef5e 100644
--- a/.idea/inspectionProfiles/Project_Default.xml
+++ b/.idea/inspectionProfiles/Project_Default.xml
@@ -74,7 +74,6 @@
     <inspection_tool class="BigDecimalEquals" enabled="true" level="WARNING" enabled_by_default="true" />
     <inspection_tool class="BreakStatement" enabled="true" level="WARNING" enabled_by_default="true" />
     <inspection_tool class="BreakStatementWithLabel" enabled="true" level="WARNING" enabled_by_default="true" />
-    <inspection_tool class="BusyWait" enabled="true" level="WARNING" enabled_by_default="true" />
     <inspection_tool class="CallToNativeMethodWhileLocked" enabled="true" level="WARNING" enabled_by_default="true" />
     <inspection_tool class="CallToStringConcatCanBeReplacedByOperator" enabled="true" level="WARNING" enabled_by_default="true" />
     <inspection_tool class="CastConflictsWithInstanceof" enabled="true" level="WARNING" enabled_by_default="true" />
@@ -215,7 +214,6 @@
       <option name="commentsAreContent" value="true" />
     </inspection_tool>
     <inspection_tool class="EmptyDirectory" enabled="true" level="WARNING" enabled_by_default="true" />
-    <inspection_tool class="EmptyInitializer" enabled="true" level="WARNING" enabled_by_default="true" />
     <inspection_tool class="EmptySynchronizedStatement" enabled="true" level="WARNING" enabled_by_default="true" />
     <inspection_tool class="EnumSwitchStatementWhichMissesCases" enabled="true" level="WARNING" enabled_by_default="true">
       <scope name="Tests" level="TYPO" enabled="true">
@@ -252,7 +250,6 @@
       <option name="myCountEnumConstants" value="false" />
       <option name="m_limit" value="20" />
     </inspection_tool>
-    <inspection_tool class="FieldMayBeFinal" enabled="true" level="WARNING" enabled_by_default="true" />
     <inspection_tool class="FieldMayBeStatic" enabled="true" level="WARNING" enabled_by_default="true" />
     <inspection_tool class="FinalizeNotProtected" enabled="true" level="WARNING" enabled_by_default="true" />
     <inspection_tool class="FloatingPointEquality" enabled="true" level="WARNING" enabled_by_default="true" />
@@ -327,11 +324,7 @@
       <option name="ignoreAbstractClasses" value="true" />
     </inspection_tool>
     <inspection_tool class="InstanceofThis" enabled="true" level="WARNING" enabled_by_default="true" />
-    <inspection_tool class="InstantiationOfUtilityClass" enabled="true" level="WARNING" enabled_by_default="true" />
     <inspection_tool class="IntLiteralMayBeLongLiteral" enabled="true" level="WARNING" enabled_by_default="true" />
-    <inspection_tool class="IntegerMultiplicationImplicitCastToLong" enabled="true" level="WARNING" enabled_by_default="true">
-      <option name="ignoreNonOverflowingCompileTimeConstants" value="true" />
-    </inspection_tool>
     <inspection_tool class="InterfaceNamingConvention" enabled="true" level="WARNING" enabled_by_default="true">
       <option name="m_regex" value="[A-Z][A-Za-z\d]*" />
       <option name="m_minLength" value="3" />
@@ -340,7 +333,6 @@
     <inspection_tool class="InterfaceNeverImplemented" enabled="true" level="WARNING" enabled_by_default="true">
       <option name="ignoreInterfacesThatOnlyDeclareConstants" value="true" />
     </inspection_tool>
-    <inspection_tool class="IteratorHasNextCallsIteratorNext" enabled="true" level="WARNING" enabled_by_default="true" />
     <inspection_tool class="IteratorNextDoesNotThrowNoSuchElementException" enabled="true" level="WARNING" enabled_by_default="true" />
     <inspection_tool class="JDBCExecuteWithNonConstantString" enabled="true" level="WARNING" enabled_by_default="true" />
     <inspection_tool class="JDBCPrepareStatementWithNonConstantString" enabled="true" level="WARNING" enabled_by_default="true" />
@@ -379,14 +371,13 @@
     </inspection_tool>
     <inspection_tool class="JavaLangImport" enabled="true" level="WARNING" enabled_by_default="true" />
     <inspection_tool class="JavaLangReflect" enabled="true" level="WARNING" enabled_by_default="true" />
-    <inspection_tool class="JavadocHtmlLint" enabled="true" level="ERROR" enabled_by_default="true" />
+    <inspection_tool class="JavadocHtmlLint" enabled="true" level="TYPO" enabled_by_default="true" />
     <inspection_tool class="JavadocReference" enabled="true" level="ERROR" enabled_by_default="true">
       <scope name="Tests" level="ERROR" enabled="false" />
     </inspection_tool>
     <inspection_tool class="LabeledStatement" enabled="true" level="WARNING" enabled_by_default="true" />
     <inspection_tool class="LengthOneStringInIndexOf" enabled="true" level="WARNING" enabled_by_default="true" />
     <inspection_tool class="LengthOneStringsInConcatenation" enabled="true" level="WARNING" enabled_by_default="true" />
-    <inspection_tool class="ListIndexOfReplaceableByContains" enabled="true" level="WARNING" enabled_by_default="true" />
     <inspection_tool class="ListenerMayUseAdapter" enabled="true" level="WARNING" enabled_by_default="true">
       <option name="checkForEmptyMethods" value="true" />
     </inspection_tool>
@@ -474,6 +465,7 @@
       <option name="ignoreForLoopDeclarations" value="true" />
     </inspection_tool>
     <inspection_tool class="MultipleTopLevelClassesInFile" enabled="true" level="WARNING" enabled_by_default="true" />
+    <inspection_tool class="MultipleVariablesInDeclaration" enabled="true" level="WARNING" enabled_by_default="true" />
     <inspection_tool class="NakedNotify" enabled="true" level="WARNING" enabled_by_default="true" />
     <inspection_tool class="NativeMethods" enabled="true" level="WARNING" enabled_by_default="true" />
     <inspection_tool class="NestedAssignment" enabled="true" level="WARNING" enabled_by_default="true" />
@@ -494,6 +486,7 @@
         <extension name="JUnit4MethodNamingConvention" enabled="true">
           <option name="m_regex" value="[a-z][A-Za-z\d]*" />
           <option name="m_minLength" value="2" />
+          <option name="m_maxLength" value="64" />
         </extension>
       </scope>
       <scope name="Production" level="WARNING" enabled="true">
@@ -592,7 +585,6 @@
     <inspection_tool class="OverriddenMethodCallDuringObjectConstruction" enabled="true" level="WARNING" enabled_by_default="true" />
     <inspection_tool class="PackageDotHtmlMayBePackageInfo" enabled="true" level="WARNING" enabled_by_default="true" />
     <inspection_tool class="PackageInMultipleModules" enabled="true" level="WARNING" enabled_by_default="true" />
-    <inspection_tool class="PackageInfoWithoutPackage" enabled="true" level="WARNING" enabled_by_default="true" />
     <inspection_tool class="PackageNamingConvention" enabled="true" level="WARNING" enabled_by_default="true">
       <option name="m_regex" value="[a-z]+\d*[a-z]*" />
       <option name="m_minLength" value="2" />
@@ -643,7 +635,6 @@
       <option name="ignoreCloneable" value="false" />
     </inspection_tool>
     <inspection_tool class="RedundantMethodOverride" enabled="true" level="WARNING" enabled_by_default="true" />
-    <inspection_tool class="RedundantSuppression" enabled="true" level="WARNING" enabled_by_default="true" />
     <inspection_tool class="ResultOfObjectAllocationIgnored" enabled="true" level="WARNING" enabled_by_default="true">
       <scope name="Tests" level="WARNING" enabled="false" />
     </inspection_tool>
@@ -713,9 +704,6 @@
     <inspection_tool class="SubtractionInCompareTo" enabled="true" level="WARNING" enabled_by_default="true" />
     <inspection_tool class="SuspiciousIndentAfterControlStatement" enabled="true" level="WARNING" enabled_by_default="true" />
     <inspection_tool class="SwitchStatementWithConfusingDeclaration" enabled="true" level="WARNING" enabled_by_default="true" />
-    <inspection_tool class="SwitchStatementWithTooFewBranches" enabled="true" level="WARNING" enabled_by_default="true">
-      <option name="m_limit" value="2" />
-    </inspection_tool>
     <inspection_tool class="SwitchStatementsWithoutDefault" enabled="true" level="WARNING" enabled_by_default="true">
       <option name="m_ignoreFullyCoveredEnums" value="true" />
     </inspection_tool>
@@ -732,16 +720,13 @@
     <inspection_tool class="SystemSetSecurityManager" enabled="true" level="WARNING" enabled_by_default="true" />
     <inspection_tool class="TailRecursion" enabled="true" level="WARNING" enabled_by_default="true" />
     <inspection_tool class="TestOnlyProblems" enabled="true" level="TYPO" enabled_by_default="true" />
-    <inspection_tool class="TextLabelInSwitchStatement" enabled="true" level="WARNING" enabled_by_default="true" />
     <inspection_tool class="ThisEscapedInConstructor" enabled="true" level="WARNING" enabled_by_default="true" />
     <inspection_tool class="ThreadDeathRethrown" enabled="true" level="WARNING" enabled_by_default="true" />
     <inspection_tool class="ThreadDumpStack" enabled="true" level="WARNING" enabled_by_default="true" />
     <inspection_tool class="ThreadLocalNotStaticFinal" enabled="true" level="WARNING" enabled_by_default="true" />
     <inspection_tool class="ThreadPriority" enabled="true" level="WARNING" enabled_by_default="true" />
-    <inspection_tool class="ThreadRun" enabled="true" level="WARNING" enabled_by_default="true" />
     <inspection_tool class="ThreadStartInConstruction" enabled="true" level="WARNING" enabled_by_default="true" />
     <inspection_tool class="ThreadStopSuspendResume" enabled="true" level="WARNING" enabled_by_default="true" />
-    <inspection_tool class="ThreadWithDefaultRunMethod" enabled="true" level="WARNING" enabled_by_default="true" />
     <inspection_tool class="ThreadYield" enabled="true" level="WARNING" enabled_by_default="true" />
     <inspection_tool class="ThreeNegationsPerMethod" enabled="true" level="WARNING" enabled_by_default="true">
       <option name="m_ignoreInEquals" value="true" />
@@ -811,21 +796,13 @@
     <inspection_tool class="UnnecessaryJavaDocLink" enabled="true" level="WARNING" enabled_by_default="true">
       <option name="ignoreInlineLinkToSuper" value="false" />
     </inspection_tool>
-    <inspection_tool class="UnnecessaryLocalVariable" enabled="true" level="WARNING" enabled_by_default="true">
-      <option name="m_ignoreImmediatelyReturnedVariables" value="true" />
+    <inspection_tool class="UnnecessaryLocalVariable" enabled="false" level="WARNING" enabled_by_default="false">
+      <option name="m_ignoreImmediatelyReturnedVariables" value="false" />
       <option name="m_ignoreAnnotatedVariables" value="false" />
     </inspection_tool>
     <inspection_tool class="UnnecessaryQualifierForThis" enabled="true" level="WARNING" enabled_by_default="true" />
     <inspection_tool class="UnnecessarySuperQualifier" enabled="true" level="WARNING" enabled_by_default="true" />
     <inspection_tool class="UnnecessaryUnaryMinus" enabled="true" level="WARNING" enabled_by_default="true" />
-    <inspection_tool class="UnpredictableBigDecimalConstructorCall" enabled="true" level="WARNING" enabled_by_default="true">
-      <option name="ignoreReferences" value="true" />
-      <option name="ignoreComplexLiterals" value="false" />
-    </inspection_tool>
-    <inspection_tool class="UnqualifiedInnerClassAccess" enabled="false" level="WARNING" enabled_by_default="false">
-      <option name="ignoreReferencesToLocalInnerClasses" value="true" />
-    </inspection_tool>
-    <inspection_tool class="UnnecessaryLocalVariable" enabled="false" level="WARNING" enabled_by_default="false" />
     <inspection_tool class="UnsecureRandomNumberGeneration" enabled="true" level="WARNING" enabled_by_default="true" />
     <inspection_tool class="UnstableApiUsage" enabled="true" level="WEAK WARNING" enabled_by_default="true">
       <scope name="Tests" level="WEAK WARNING" enabled="false" />
diff --git a/.idea/misc.xml b/.idea/misc.xml
index deb97c811..e881be664 100644
--- a/.idea/misc.xml
+++ b/.idea/misc.xml
@@ -1,12 +1,17 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
+  <component name="FrameworkDetectionExcludesConfiguration">
+    <file type="web" url="file://$PROJECT_DIR$" />
+  </component>
   <component name="JavaScriptSettings">
     <option name="languageLevel" value="ES6" />
   </component>
   <component name="NullableNotNullManager">
+    <option name="myDefaultNullable" value="org.jetbrains.annotations.Nullable" />
+    <option name="myDefaultNotNull" value="org.jetbrains.annotations.NotNull" />
     <option name="myNullables">
       <value>
-        <list size="9">
+        <list size="14">
           <item index="0" class="java.lang.String" itemvalue="org.jetbrains.annotations.Nullable" />
           <item index="1" class="java.lang.String" itemvalue="javax.annotation.Nullable" />
           <item index="2" class="java.lang.String" itemvalue="javax.annotation.CheckForNull" />
@@ -16,12 +21,17 @@
           <item index="6" class="java.lang.String" itemvalue="org.checkerframework.checker.nullness.qual.Nullable" />
           <item index="7" class="java.lang.String" itemvalue="org.checkerframework.checker.nullness.compatqual.NullableDecl" />
           <item index="8" class="java.lang.String" itemvalue="org.checkerframework.checker.nullness.compatqual.NullableType" />
+          <item index="9" class="java.lang.String" itemvalue="androidx.annotation.RecentlyNullable" />
+          <item index="10" class="java.lang.String" itemvalue="com.android.annotations.Nullable" />
+          <item index="11" class="java.lang.String" itemvalue="org.eclipse.jdt.annotation.Nullable" />
+          <item index="12" class="java.lang.String" itemvalue="io.reactivex.annotations.Nullable" />
+          <item index="13" class="java.lang.String" itemvalue="io.reactivex.rxjava3.annotations.Nullable" />
         </list>
       </value>
     </option>
     <option name="myNotNulls">
       <value>
-        <list size="9">
+        <list size="14">
           <item index="0" class="java.lang.String" itemvalue="org.jetbrains.annotations.NotNull" />
           <item index="1" class="java.lang.String" itemvalue="javax.annotation.Nonnull" />
           <item index="2" class="java.lang.String" itemvalue="javax.validation.constraints.NotNull" />
@@ -31,9 +41,14 @@
           <item index="6" class="java.lang.String" itemvalue="org.checkerframework.checker.nullness.qual.NonNull" />
           <item index="7" class="java.lang.String" itemvalue="org.checkerframework.checker.nullness.compatqual.NonNullDecl" />
           <item index="8" class="java.lang.String" itemvalue="org.checkerframework.checker.nullness.compatqual.NonNullType" />
+          <item index="9" class="java.lang.String" itemvalue="androidx.annotation.RecentlyNonNull" />
+          <item index="10" class="java.lang.String" itemvalue="com.android.annotations.NonNull" />
+          <item index="11" class="java.lang.String" itemvalue="org.eclipse.jdt.annotation.NonNull" />
+          <item index="12" class="java.lang.String" itemvalue="io.reactivex.annotations.NonNull" />
+          <item index="13" class="java.lang.String" itemvalue="io.reactivex.rxjava3.annotations.NonNull" />
         </list>
       </value>
     </option>
   </component>
   <component name="ProjectRootManager" version="2" languageLevel="JDK_1_8" default="false" project-jdk-name="1.8" project-jdk-type="JavaSDK" />
-</project>
\ No newline at end of file
+</project>
diff --git a/buildSrc/src/main/kotlin/io/spine/gradle/internal/IncrementGuard.kt b/buildSrc/src/main/kotlin/io/spine/gradle/internal/IncrementGuard.kt
index 72eb03227..406f71fd7 100644
--- a/buildSrc/src/main/kotlin/io/spine/gradle/internal/IncrementGuard.kt
+++ b/buildSrc/src/main/kotlin/io/spine/gradle/internal/IncrementGuard.kt
@@ -51,8 +51,10 @@ class IncrementGuard : Plugin<Project> {
 
             shouldRunAfter("test")
             if (!shouldCheckVersion()) {
-                logger.info("The build does not represent a GitHub Actions feature branch job, " +
-                        "the `checkVersionIncrement` task is disabled.")
+                logger.info(
+                    "The build does not represent a GitHub Actions feature branch job, " +
+                            "the `checkVersionIncrement` task is disabled."
+                )
                 this.enabled = false
             }
         }
diff --git a/buildSrc/src/main/kotlin/io/spine/gradle/internal/RunBuild.kt b/buildSrc/src/main/kotlin/io/spine/gradle/internal/RunBuild.kt
index 48dd298ef..62c3a77aa 100644
--- a/buildSrc/src/main/kotlin/io/spine/gradle/internal/RunBuild.kt
+++ b/buildSrc/src/main/kotlin/io/spine/gradle/internal/RunBuild.kt
@@ -70,8 +70,8 @@ open class RunBuild : DefaultTask() {
         val command = mutableListOf<String>()
         command.add("${project.rootDir}/$script")
         val shouldClean = project.gradle
-                                 .taskGraph
-                                 .hasTask(":clean")
+            .taskGraph
+            .hasTask(":clean")
         if (shouldClean) {
             command.add("clean")
         }
@@ -83,10 +83,10 @@ open class RunBuild : DefaultTask() {
     }
 
     private fun buildProcess(command: List<String>, errorOut: File, debugOut: File) =
-            ProcessBuilder()
-                    .command(command)
-                    .directory(project.file(directory))
-                    .redirectError(errorOut)
-                    .redirectOutput(debugOut)
-                    .start()
+        ProcessBuilder()
+            .command(command)
+            .directory(project.file(directory))
+            .redirectError(errorOut)
+            .redirectOutput(debugOut)
+            .start()
 }
diff --git a/buildSrc/src/main/kotlin/io/spine/gradle/internal/deps.kt b/buildSrc/src/main/kotlin/io/spine/gradle/internal/deps.kt
index be5d1d097..9cbdc1721 100644
--- a/buildSrc/src/main/kotlin/io/spine/gradle/internal/deps.kt
+++ b/buildSrc/src/main/kotlin/io/spine/gradle/internal/deps.kt
@@ -32,9 +32,11 @@ import java.net.URI
  *  https://github.com/uber/NullAway/blob/master/gradle/dependencies.gradle
  */
 
-data class Repository(val releases: String,
-                      val snapshots: String,
-                      val credentials: String)
+data class Repository(
+    val releases: String,
+    val snapshots: String,
+    val credentials: String
+)
 
 /**
  * Repositories to which we may publish. Normally, only one repository will be used.
@@ -43,14 +45,14 @@ data class Repository(val releases: String,
  */
 object PublishingRepos {
     val mavenTeamDev = Repository(
-            releases = "http://maven.teamdev.com/repository/spine",
-            snapshots = "http://maven.teamdev.com/repository/spine-snapshots",
-            credentials = "credentials.properties"
+        releases = "http://maven.teamdev.com/repository/spine",
+        snapshots = "http://maven.teamdev.com/repository/spine-snapshots",
+        credentials = "credentials.properties"
     )
     val cloudRepo = Repository(
-            releases = "https://spine.mycloudrepo.io/public/repositories/releases",
-            snapshots = "https://spine.mycloudrepo.io/public/repositories/snapshots",
-            credentials = "cloudrepo.properties"
+        releases = "https://spine.mycloudrepo.io/public/repositories/releases",
+        snapshots = "https://spine.mycloudrepo.io/public/repositories/snapshots",
+        credentials = "cloudrepo.properties"
     )
 }
 
@@ -126,25 +128,25 @@ object GradlePlugins {
 object Build {
     val errorProneJavac        = "com.google.errorprone:javac:${Versions.errorProneJavac}"
     val errorProneAnnotations = listOf(
-            "com.google.errorprone:error_prone_annotations:${Versions.errorProne}",
-            "com.google.errorprone:error_prone_type_annotations:${Versions.errorProne}"
+        "com.google.errorprone:error_prone_annotations:${Versions.errorProne}",
+        "com.google.errorprone:error_prone_type_annotations:${Versions.errorProne}"
     )
     val errorProneCheckApi     = "com.google.errorprone:error_prone_check_api:${Versions.errorProne}"
     val errorProneCore         = "com.google.errorprone:error_prone_core:${Versions.errorProne}"
     val errorProneTestHelpers  = "com.google.errorprone:error_prone_test_helpers:${Versions.errorProne}"
     val checkerAnnotations     = "org.checkerframework:checker-qual:${Versions.checkerFramework}"
     val checkerDataflow        = listOf(
-            "org.checkerframework:dataflow:${Versions.checkerFramework}",
-            "org.checkerframework:javacutil:${Versions.checkerFramework}"
+        "org.checkerframework:dataflow:${Versions.checkerFramework}",
+        "org.checkerframework:javacutil:${Versions.checkerFramework}"
     )
     val autoCommon             = "com.google.auto:auto-common:${Versions.autoCommon}"
     val autoService            = AutoService
     val jsr305Annotations      = "com.google.code.findbugs:jsr305:${Versions.findBugs}"
     val guava                  = "com.google.guava:guava:${Versions.guava}"
     val flogger                = "com.google.flogger:flogger:${Versions.flogger}"
-    val protobuf = listOf(
-            "com.google.protobuf:protobuf-java:${Versions.protobuf}",
-            "com.google.protobuf:protobuf-java-util:${Versions.protobuf}"
+    val protobuf               = listOf(
+        "com.google.protobuf:protobuf-java:${Versions.protobuf}",
+        "com.google.protobuf:protobuf-java-util:${Versions.protobuf}"
     )
     val protoc                 = "com.google.protobuf:protoc:${Versions.protobuf}"
     val googleHttpClient       = "com.google.http-client:google-http-client:${Versions.httpClient}"
@@ -224,20 +226,20 @@ object Runtime {
 
 object Test {
     val junit4        = "junit:junit:${Versions.junit4}"
-    val junit5Api = listOf(
-            "org.junit.jupiter:junit-jupiter-api:${Versions.junit5}",
-            "org.junit.jupiter:junit-jupiter-params:${Versions.junit5}",
-            "org.apiguardian:apiguardian-api:${Versions.apiguardian}"
+    val junit5Api     = listOf(
+        "org.junit.jupiter:junit-jupiter-api:${Versions.junit5}",
+        "org.junit.jupiter:junit-jupiter-params:${Versions.junit5}",
+        "org.apiguardian:apiguardian-api:${Versions.apiguardian}"
     )
     val junit5Runner  = "org.junit.jupiter:junit-jupiter-engine:${Versions.junit5}"
     val junitPioneer  = "org.junit-pioneer:junit-pioneer:${Versions.junitPioneer}"
     val guavaTestlib  = "com.google.guava:guava-testlib:${Versions.guava}"
     val mockito       = "org.mockito:mockito-core:2.12.0"
     val hamcrest      = "org.hamcrest:hamcrest-all:1.3"
-    val truth = listOf(
-            "com.google.truth:truth:${Versions.truth}",
-            "com.google.truth.extensions:truth-java8-extension:${Versions.truth}",
-            "com.google.truth.extensions:truth-proto-extension:${Versions.truth}"
+    val truth         = listOf(
+        "com.google.truth:truth:${Versions.truth}",
+        "com.google.truth.extensions:truth-java8-extension:${Versions.truth}",
+        "com.google.truth.extensions:truth-proto-extension:${Versions.truth}"
     )
     @Deprecated("Use Flogger over SLF4J.",
             replaceWith = ReplaceWith("Deps.runtime.floggerSystemBackend"))
@@ -298,36 +300,36 @@ object DependencyResolution {
                 cacheChangingModulesFor(0, "seconds")
                 @Suppress("DEPRECATION") // Force SLF4J version.
                 force(
-                        Deps.build.slf4j,
-                        Deps.build.errorProneAnnotations,
-                        Deps.build.jsr305Annotations,
-                        Deps.build.checkerAnnotations,
-                        Deps.build.autoCommon,
-                        Deps.build.guava,
-                        Deps.build.animalSniffer,
-                        Deps.build.protobuf,
-                        Deps.test.guavaTestlib,
-                        Deps.test.truth,
-                        Deps.test.junit5Api,
-                        Deps.test.junit4,
-
-                        // Transitive dependencies of 3rd party components that we don't use directly.
-                        "org.junit.platform:junit-platform-commons:${Versions.junitPlatform}",
-                        "com.google.auto.value:auto-value-annotations:1.7.4",
-                        "com.google.auto.service:auto-service-annotations:1.0-rc7",
-                        "com.google.code.gson:gson:2.8.6",
-                        "com.google.j2objc:j2objc-annotations:1.3",
-                        "org.codehaus.plexus:plexus-utils:3.3.0",
-                        "com.squareup.okio:okio:1.17.5", // Last version before next major.
-                        "commons-cli:commons-cli:1.4",
-
-                        // Force discontinued transitive dependency until everybody migrates off it.
-                        "org.checkerframework:checker-compat-qual:2.5.5",
-
-                        "commons-logging:commons-logging:1.2",
-
-                        // Force the Gradle Protobuf plugin version.
-                        Deps.build.gradlePlugins.protobuf
+                    Deps.build.slf4j,
+                    Deps.build.errorProneAnnotations,
+                    Deps.build.jsr305Annotations,
+                    Deps.build.checkerAnnotations,
+                    Deps.build.autoCommon,
+                    Deps.build.guava,
+                    Deps.build.animalSniffer,
+                    Deps.build.protobuf,
+                    Deps.test.guavaTestlib,
+                    Deps.test.truth,
+                    Deps.test.junit5Api,
+                    Deps.test.junit4,
+
+                    // Transitive dependencies of 3rd party components that we don't use directly.
+                    "org.junit.platform:junit-platform-commons:${Versions.junitPlatform}",
+                    "com.google.auto.value:auto-value-annotations:1.7.4",
+                    "com.google.auto.service:auto-service-annotations:1.0-rc7",
+                    "com.google.code.gson:gson:2.8.6",
+                    "com.google.j2objc:j2objc-annotations:1.3",
+                    "org.codehaus.plexus:plexus-utils:3.3.0",
+                    "com.squareup.okio:okio:1.17.5", // Last version before next major.
+                    "commons-cli:commons-cli:1.4",
+
+                    // Force discontinued transitive dependency until everybody migrates off it.
+                    "org.checkerframework:checker-compat-qual:2.5.5",
+
+                    "commons-logging:commons-logging:1.2",
+
+                    // Force the Gradle Protobuf plugin version.
+                    Deps.build.gradlePlugins.protobuf
                 )
             }
         }
@@ -338,10 +340,13 @@ object DependencyResolution {
         excludeProtoLite(configurations, "testRuntime")
     }
 
-    private fun excludeProtoLite(configurations: ConfigurationContainer,
-                                 configurationName: String) {
-        configurations.named(configurationName).get()
-                .exclude(mapOf("group" to "com.google.protobuf", "module" to "protobuf-lite"))
+    private fun excludeProtoLite(
+        configurations: ConfigurationContainer,
+        configurationName: String
+    ) {
+        configurations
+            .named(configurationName).get()
+            .exclude(mapOf("group" to "com.google.protobuf", "module" to "protobuf-lite"))
     }
 
     fun defaultRepositories(repositories: RepositoryHandler) {
diff --git a/config b/config
index cfb3f751f..767dfbc09 160000
--- a/config
+++ b/config
@@ -1 +1 @@
-Subproject commit cfb3f751f231403387899aef0887d967dd36a805
+Subproject commit 767dfbc093bb99c44e631034b1c69cbc58bc3536

From 9b594dee04d0081e32b9cb934b02d0f2bce340e4 Mon Sep 17 00:00:00 2001
From: Yuri Sergiichuk <yuri.sergiichuk@teamdev.com>
Date: Fri, 4 Dec 2020 14:16:59 +0200
Subject: [PATCH 03/41] Reformat as per the new config.

---
 build.gradle.kts                              | 82 ++++++++++---------
 .../io/spine/gradle/internal/LocalDeps.kt     |  2 +-
 client-js/build.gradle.kts                    | 30 +++++--
 firebase-web/build.gradle.kts                 |  6 +-
 web/build.gradle.kts                          |  6 +-
 5 files changed, 77 insertions(+), 49 deletions(-)

diff --git a/build.gradle.kts b/build.gradle.kts
index e56267fe5..73817b07d 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -50,7 +50,7 @@ buildscript {
 }
 
 plugins {
-    java
+    `java-library`
     jacoco
     idea
     pmd
@@ -113,9 +113,11 @@ subprojects {
     dependencies {
         errorprone(Deps.build.errorProneCore)
         errorproneJavac(Deps.build.errorProneJavac)
+
         implementation(Deps.build.guava)
         implementation(Deps.build.checkerAnnotations)
         Deps.build.errorProneAnnotations.forEach { implementation(it) }
+
         testImplementation(Deps.test.guavaTestlib)
         Deps.test.junit5Api.forEach { testImplementation(it) }
         testImplementation(Deps.test.junit5Runner)
@@ -145,59 +147,59 @@ subprojects {
              * in classpath, and assumes they implement the Type URLs.
              */
             force(
-                    "io.opencensus:opencensus-api:0.21.0",
-                    "io.opencensus:opencensus-contrib-http-util:0.18.0",
+                "io.opencensus:opencensus-api:0.21.0",
+                "io.opencensus:opencensus-contrib-http-util:0.18.0",
 
-                    "io.grpc:grpc-core:${Deps.versions.grpc}",
-                    "io.grpc:grpc-stub:${Deps.versions.grpc}",
-                    "io.grpc:grpc-okhttp:${Deps.versions.grpc}",
-                    "io.grpc:grpc-protobuf:${Deps.versions.grpc}",
-                    "io.grpc:grpc-netty:${Deps.versions.grpc}",
-                    "io.grpc:grpc-context:${Deps.versions.grpc}",
-                    "io.grpc:grpc-stub:${Deps.versions.grpc}",
-                    "io.grpc:grpc-protobuf:${Deps.versions.grpc}",
-                    "io.grpc:grpc-core:${Deps.versions.grpc}",
+                "io.grpc:grpc-core:${Deps.versions.grpc}",
+                "io.grpc:grpc-stub:${Deps.versions.grpc}",
+                "io.grpc:grpc-okhttp:${Deps.versions.grpc}",
+                "io.grpc:grpc-protobuf:${Deps.versions.grpc}",
+                "io.grpc:grpc-netty:${Deps.versions.grpc}",
+                "io.grpc:grpc-context:${Deps.versions.grpc}",
+                "io.grpc:grpc-stub:${Deps.versions.grpc}",
+                "io.grpc:grpc-protobuf:${Deps.versions.grpc}",
+                "io.grpc:grpc-core:${Deps.versions.grpc}",
 
-                    "com.google.code.gson:gson:2.7",
-                    "com.google.api:api-common:1.7.0",
-                    "com.google.api.grpc:proto-google-common-protos:1.0.0",
-                    "com.google.api.grpc:proto-google-iam-v1:0.1.28",
+                "com.google.code.gson:gson:2.7",
+                "com.google.api:api-common:1.7.0",
+                "com.google.api.grpc:proto-google-common-protos:1.0.0",
+                "com.google.api.grpc:proto-google-iam-v1:0.1.28",
 
-                    "com.google.cloud:google-cloud-core:1.91.3",
-                    "com.google.api:gax:1.49.1",
+                "com.google.cloud:google-cloud-core:1.91.3",
+                "com.google.api:gax:1.49.1",
 
-                    "com.google.oauth-client:google-oauth-client:1.25.0",
+                "com.google.oauth-client:google-oauth-client:1.25.0",
 
-                    "com.google.auth:google-auth-library-credentials:0.11.0",
-                    "com.google.auth:google-auth-library-oauth2-http:0.11.0",
+                "com.google.auth:google-auth-library-credentials:0.11.0",
+                "com.google.auth:google-auth-library-oauth2-http:0.11.0",
 
-                    "com.google.j2objc:j2objc-annotations:1.3",
+                "com.google.j2objc:j2objc-annotations:1.3",
 
-                    "com.google.http-client:google-http-client:1.29.0",
-                    "com.google.http-client:google-http-client-jackson2:1.29.0",
+                "com.google.http-client:google-http-client:1.29.0",
+                "com.google.http-client:google-http-client-jackson2:1.29.0",
 
-                    "com.google.api-client:google-api-client:1.30.9",
+                "com.google.api-client:google-api-client:1.30.9",
 
-                    "org.apache.httpcomponents:httpclient:4.5.5",
+                "org.apache.httpcomponents:httpclient:4.5.5",
 
-                    "com.fasterxml.jackson.core:jackson-core:2.9.9",
-                    "commons-collections:commons-collections:3.2.2",
+                "com.fasterxml.jackson.core:jackson-core:2.9.9",
+                "commons-collections:commons-collections:3.2.2",
 
-                    "io.netty:netty-common:4.1.34.Final",
-                    "io.netty:netty-buffer:4.1.34.Final",
-                    "io.netty:netty-transport:4.1.34.Final",
-                    "io.netty:netty-handler:4.1.34.Final",
-                    "io.netty:netty-codec-http:4.1.34.Final",
+                "io.netty:netty-common:4.1.34.Final",
+                "io.netty:netty-buffer:4.1.34.Final",
+                "io.netty:netty-transport:4.1.34.Final",
+                "io.netty:netty-handler:4.1.34.Final",
+                "io.netty:netty-codec-http:4.1.34.Final",
 
-                    Deps.build.servletApi,
+                Deps.build.servletApi,
 
-                    "org.eclipse.jetty.orbit:javax.servlet.jsp:2.2.0.v201112011158",
-                    "org.eclipse.jetty.toolchain:jetty-schemas:3.1",
+                "org.eclipse.jetty.orbit:javax.servlet.jsp:2.2.0.v201112011158",
+                "org.eclipse.jetty.toolchain:jetty-schemas:3.1",
 
-                    // Transitive dependencies from `core-java` may have different (older) versions.
-                    "io.spine:spine-base:$spineBaseVersion",
-                    "io.spine:spine-testlib:$spineBaseVersion",
-                    "io.spine:spine-time:$spineTimeVersion"
+                // Transitive dependencies from `core-java` may have different (older) versions.
+                "io.spine:spine-base:$spineBaseVersion",
+                "io.spine:spine-testlib:$spineBaseVersion",
+                "io.spine:spine-time:$spineTimeVersion"
             )
         }
     }
diff --git a/buildSrc/src/main/kotlin/io/spine/gradle/internal/LocalDeps.kt b/buildSrc/src/main/kotlin/io/spine/gradle/internal/LocalDeps.kt
index 48ab3419e..486dada51 100644
--- a/buildSrc/src/main/kotlin/io/spine/gradle/internal/LocalDeps.kt
+++ b/buildSrc/src/main/kotlin/io/spine/gradle/internal/LocalDeps.kt
@@ -28,4 +28,4 @@ val Build.servletApi: String
 
 val Runtime.slf4jJul: String
     get() = @Suppress("DEPRECATION") // SLF4J version.
-            "org.slf4j:slf4j-jdk14:${Deps.versions.slf4j}"
+    "org.slf4j:slf4j-jdk14:${Deps.versions.slf4j}"
diff --git a/client-js/build.gradle.kts b/client-js/build.gradle.kts
index 9faf775b6..0f96f6ab9 100644
--- a/client-js/build.gradle.kts
+++ b/client-js/build.gradle.kts
@@ -18,8 +18,8 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-import com.google.common.io.Files
 import com.google.common.collect.Lists
+import com.google.common.io.Files
 
 
 apply(from = "$rootDir/scripts/js.gradle")
@@ -28,19 +28,31 @@ val spineCoreVersion: String by extra
 
 dependencies {
     protobuf(project(":web"))
-    protobuf(group = "io.spine", name = "spine-client", version = spineCoreVersion, classifier = "proto")
-    testProtobuf(group = "io.spine", name = "spine-client", version = spineCoreVersion, classifier = "proto")
+    protobuf(
+        group = "io.spine",
+        name = "spine-client",
+        version = spineCoreVersion,
+        classifier = "proto"
+    )
+    testProtobuf(
+        group = "io.spine",
+        name = "spine-client",
+        version = spineCoreVersion,
+        classifier = "proto"
+    )
 }
 
 idea.module {
     sourceDirs.add(file(project.extra["srcDir"]))
     testSourceDirs.add(file(project.extra["testSrcDir"]))
 
-    excludeDirs.addAll(files(
+    excludeDirs.addAll(
+        files(
             project.extra["nycOutputDir"],
             project.extra["genProtoMain"],
             project.extra["genProtoTest"]
-    ))
+        )
+    )
 }
 
 
@@ -67,7 +79,13 @@ tasks.compileTestJava {
 val jsDocDir = Files.createTempDir()
 
 val jsDoc by tasks.registering(type = Exec::class) {
-    commandLine("$projectDir/node_modules/.bin/jsdoc", "-r", "-d", jsDocDir.path, "$projectDir/main/")
+    commandLine(
+        "$projectDir/node_modules/.bin/jsdoc",
+        "-r",
+        "-d",
+        jsDocDir.path,
+        "$projectDir/main/"
+    )
 }
 
 afterEvaluate {
diff --git a/firebase-web/build.gradle.kts b/firebase-web/build.gradle.kts
index 76b3f4db0..018ca9390 100644
--- a/firebase-web/build.gradle.kts
+++ b/firebase-web/build.gradle.kts
@@ -18,7 +18,11 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-import com.google.protobuf.gradle.*
+import com.google.protobuf.gradle.builtins
+import com.google.protobuf.gradle.generateProtoTasks
+import com.google.protobuf.gradle.id
+import com.google.protobuf.gradle.protobuf
+import com.google.protobuf.gradle.protoc
 import io.spine.gradle.internal.DependencyResolution
 import io.spine.gradle.internal.Deps
 import io.spine.gradle.internal.slf4jJul
diff --git a/web/build.gradle.kts b/web/build.gradle.kts
index ecba8937f..343a7cb2c 100644
--- a/web/build.gradle.kts
+++ b/web/build.gradle.kts
@@ -18,7 +18,11 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-import com.google.protobuf.gradle.*
+import com.google.protobuf.gradle.builtins
+import com.google.protobuf.gradle.generateProtoTasks
+import com.google.protobuf.gradle.id
+import com.google.protobuf.gradle.protobuf
+import com.google.protobuf.gradle.protoc
 import io.spine.gradle.internal.DependencyResolution
 import io.spine.gradle.internal.Deps
 import io.spine.gradle.internal.IncrementGuard

From 800cd5df6b896b7dbad68352ad0bfa74d52a754c Mon Sep 17 00:00:00 2001
From: Yuri Sergiichuk <yuri.sergiichuk@teamdev.com>
Date: Fri, 4 Dec 2020 14:21:46 +0200
Subject: [PATCH 04/41] Use new Gradle `compileOnlyApi` configuration.

---
 build.gradle.kts | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/build.gradle.kts b/build.gradle.kts
index 73817b07d..4df3ac134 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -115,15 +115,17 @@ subprojects {
         errorproneJavac(Deps.build.errorProneJavac)
 
         implementation(Deps.build.guava)
-        implementation(Deps.build.checkerAnnotations)
-        Deps.build.errorProneAnnotations.forEach { implementation(it) }
 
+        compileOnlyApi(Deps.build.checkerAnnotations)
+        compileOnlyApi(Deps.build.jsr305Annotations)
+        Deps.build.errorProneAnnotations.forEach { compileOnlyApi(it) }
+
+        testImplementation("io.spine:spine-testutil-client:$spineCoreVersion")
         testImplementation(Deps.test.guavaTestlib)
         Deps.test.junit5Api.forEach { testImplementation(it) }
         testImplementation(Deps.test.junit5Runner)
         testImplementation(Deps.test.mockito)
         testImplementation(Deps.test.hamcrest)
-        testImplementation("io.spine:spine-testutil-client:$spineCoreVersion")
     }
 
     DependencyResolution.forceConfiguration(configurations)

From 9179bb84d500f63950a11bceaa8264c366b8c6b6 Mon Sep 17 00:00:00 2001
From: Yuri Sergiichuk <yuri.sergiichuk@teamdev.com>
Date: Fri, 4 Dec 2020 14:32:06 +0200
Subject: [PATCH 05/41] Drop hamcrest usage.

---
 build.gradle.kts                              |  6 +--
 .../spine/web/future/FutureObserverTest.java  | 40 +++++++++++++------
 2 files changed, 30 insertions(+), 16 deletions(-)

diff --git a/build.gradle.kts b/build.gradle.kts
index 4df3ac134..65db30911 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -122,10 +122,10 @@ subprojects {
 
         testImplementation("io.spine:spine-testutil-client:$spineCoreVersion")
         testImplementation(Deps.test.guavaTestlib)
-        Deps.test.junit5Api.forEach { testImplementation(it) }
-        testImplementation(Deps.test.junit5Runner)
         testImplementation(Deps.test.mockito)
-        testImplementation(Deps.test.hamcrest)
+        Deps.test.junit5Api.forEach { testImplementation(it) }
+        Deps.test.truth.forEach { testImplementation(it) }
+        testRuntimeOnly(Deps.test.junit5Runner)
     }
 
     DependencyResolution.forceConfiguration(configurations)
diff --git a/web/src/test/java/io/spine/web/future/FutureObserverTest.java b/web/src/test/java/io/spine/web/future/FutureObserverTest.java
index 9b13c3ace..4435f737f 100644
--- a/web/src/test/java/io/spine/web/future/FutureObserverTest.java
+++ b/web/src/test/java/io/spine/web/future/FutureObserverTest.java
@@ -20,19 +20,19 @@
 
 package io.spine.web.future;
 
+import com.google.common.truth.StringSubject;
+import com.google.errorprone.annotations.CanIgnoreReturnValue;
 import org.junit.jupiter.api.DisplayName;
 import org.junit.jupiter.api.Test;
 
 import java.util.concurrent.CompletionException;
 
 import static com.google.common.base.Throwables.getRootCause;
-import static org.hamcrest.MatcherAssert.assertThat;
-import static org.hamcrest.Matchers.instanceOf;
+import static com.google.common.truth.Truth.assertThat;
 import static org.junit.jupiter.api.Assertions.assertEquals;
-import static org.junit.jupiter.api.Assertions.assertNull;
 import static org.junit.jupiter.api.Assertions.assertThrows;
 
-@DisplayName("FutureObserver should")
+@DisplayName("`FutureObserver` should")
 class FutureObserverTest {
 
     @Test
@@ -41,9 +41,9 @@ void testCreateDefault() {
         FutureObserver<String> observer = FutureObserver.create();
         String value = "hello";
         observer.onNext(value);
-        assertEquals(value, observer.toFuture().join());
+        assertResult(observer).isEqualTo(value);
         observer.onCompleted();
-        assertEquals(value, observer.toFuture().join());
+        assertResult(observer).isEqualTo(value);
     }
 
     @Test
@@ -51,7 +51,7 @@ void testCreateDefault() {
     void testDefaultNull() {
         FutureObserver<String> observer = FutureObserver.create();
         observer.onCompleted();
-        assertNull(observer.toFuture().join());
+        assertResult(observer).isNull();
     }
 
     @Test
@@ -60,7 +60,7 @@ void testDefaultValue() {
         String defaultValue = "Aquaman";
         FutureObserver<String> observer = FutureObserver.withDefault(defaultValue);
         observer.onCompleted();
-        assertEquals(defaultValue, observer.toFuture().join());
+        assertResult(observer).isEqualTo(defaultValue);
     }
 
     @Test
@@ -77,13 +77,26 @@ void testOverrideWithError() {
         FutureObserver<String> observer = FutureObserver.create();
         String value = "Titanic";
         observer.onNext(value);
-        assertEquals(value, observer.toFuture().join());
+        assertEquals(value, observer.toFuture()
+                                    .join());
         observer.onError(new IcebergCollisionException());
-        Throwable thrown = assertThrows(CompletionException.class,
-                                        () -> observer.toFuture()
-                                                      .join());
+        Throwable thrown = assertThrows(
+                CompletionException.class,
+                () -> observerResult(observer)
+        );
         Throwable rootCause = getRootCause(thrown);
-        assertThat(rootCause, instanceOf(IcebergCollisionException.class));
+        assertThat(rootCause).isInstanceOf(IcebergCollisionException.class);
+    }
+
+    private static StringSubject assertResult(FutureObserver<String> observer) {
+        return assertThat(observerResult(observer));
+    }
+
+    @CanIgnoreReturnValue
+    private static <T> T observerResult(FutureObserver<T> observer) {
+        return observer
+                .toFuture()
+                .join();
     }
 
     /**
@@ -92,6 +105,7 @@ void testOverrideWithError() {
      * <p>This exception type exists in order to uniquely flag an error origin.
      */
     private static final class IcebergCollisionException extends Exception {
+
         private static final long serialVersionUID = 0L;
     }
 }

From e09f82eac4067973e56fa803256f7aaffdfcfb2a Mon Sep 17 00:00:00 2001
From: Yuri Sergiichuk <yuri.sergiichuk@teamdev.com>
Date: Fri, 4 Dec 2020 14:55:20 +0200
Subject: [PATCH 06/41] Add extendable mocked servlet primitives.

---
 .../io/spine/web/given/MockedRequest.java     | 407 ++++++++++++++++++
 .../io/spine/web/given/MockedResponse.java    | 208 +++++++++
 2 files changed, 615 insertions(+)
 create mode 100644 testutil-web/src/main/java/io/spine/web/given/MockedRequest.java
 create mode 100644 testutil-web/src/main/java/io/spine/web/given/MockedResponse.java

diff --git a/testutil-web/src/main/java/io/spine/web/given/MockedRequest.java b/testutil-web/src/main/java/io/spine/web/given/MockedRequest.java
new file mode 100644
index 000000000..ef746d35c
--- /dev/null
+++ b/testutil-web/src/main/java/io/spine/web/given/MockedRequest.java
@@ -0,0 +1,407 @@
+/*
+ * Copyright (c) 2000-2020 TeamDev Ltd. All rights reserved.
+ * TeamDev PROPRIETARY and CONFIDENTIAL.
+ * Use is subject to license terms.
+ */
+
+package io.spine.web.given;
+
+import com.google.common.collect.ImmutableMap;
+import org.checkerframework.checker.nullness.qual.Nullable;
+
+import javax.servlet.AsyncContext;
+import javax.servlet.DispatcherType;
+import javax.servlet.RequestDispatcher;
+import javax.servlet.ServletContext;
+import javax.servlet.ServletInputStream;
+import javax.servlet.ServletRequest;
+import javax.servlet.ServletResponse;
+import javax.servlet.http.Cookie;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import javax.servlet.http.HttpSession;
+import javax.servlet.http.HttpUpgradeHandler;
+import javax.servlet.http.Part;
+import java.io.BufferedReader;
+import java.security.Principal;
+import java.util.Collection;
+import java.util.Enumeration;
+import java.util.Locale;
+import java.util.Map;
+
+/**
+ * A mock servlet request that returns a pre-defined request URI and headers.
+ *
+ * @apiNote Some of the methods are marked as {@linkplain Deprecated deprecated} to avoid
+ *         the deprecation warnings, as their {@code super} methods are marked as such.
+ */
+public class MockedRequest implements HttpServletRequest {
+
+    private final ImmutableMap<String, String> headers;
+    private final String requestUri;
+
+    private MockedRequest(Map<String, String> headers, String uri) {
+        this.headers = ImmutableMap.copyOf(headers);
+        this.requestUri = uri;
+    }
+
+    /**
+     * Creates a new mock request.
+     */
+    public static ServletRequest create(String requestUri) {
+        return create(ImmutableMap.of(), requestUri);
+    }
+
+    /**
+     * Creates a new mock request with headers.
+     */
+    public static ServletRequest create(Map<String, String> headers, String requestUri) {
+        return new MockedRequest(headers, requestUri);
+    }
+
+    @Override
+    public String getRequestURI() {
+        return requestUri;
+    }
+
+    // All methods below are intentionally no-op.
+
+    @Override
+    public @Nullable String getAuthType() {
+        return null;
+    }
+
+    @Override
+    public @Nullable Cookie[] getCookies() {
+        return null;
+    }
+
+    @Override
+    public long getDateHeader(String name) {
+        return 0;
+    }
+
+    @Override
+    public @Nullable String getHeader(String name) {
+        return headers.get(name);
+    }
+
+    @Override
+    public @Nullable Enumeration<String> getHeaders(String name) {
+        return null;
+    }
+
+    @Override
+    public @Nullable Enumeration<String> getHeaderNames() {
+        return null;
+    }
+
+    @Override
+    public int getIntHeader(String name) {
+        return 0;
+    }
+
+    @Override
+    public @Nullable String getMethod() {
+        return null;
+    }
+
+    @Override
+    public @Nullable String getPathInfo() {
+        return null;
+    }
+
+    @Override
+    public @Nullable String getPathTranslated() {
+        return null;
+    }
+
+    @Override
+    public @Nullable String getContextPath() {
+        return null;
+    }
+
+    @Override
+    public @Nullable String getQueryString() {
+        return null;
+    }
+
+    @Override
+    public @Nullable String getRemoteUser() {
+        return null;
+    }
+
+    @Override
+    public boolean isUserInRole(String role) {
+        return false;
+    }
+
+    @Override
+    public @Nullable Principal getUserPrincipal() {
+        return null;
+    }
+
+    @Override
+    public @Nullable String getRequestedSessionId() {
+        return null;
+    }
+
+    @Override
+    public @Nullable StringBuffer getRequestURL() {
+        return null;
+    }
+
+    @Override
+    public @Nullable String getServletPath() {
+        return null;
+    }
+
+    @Override
+    public @Nullable HttpSession getSession(boolean create) {
+        return null;
+    }
+
+    @Override
+    public @Nullable HttpSession getSession() {
+        return null;
+    }
+
+    @Override
+    public @Nullable String changeSessionId() {
+        return null;
+    }
+
+    @Override
+    public boolean isRequestedSessionIdValid() {
+        return false;
+    }
+
+    @Override
+    public boolean isRequestedSessionIdFromCookie() {
+        return false;
+    }
+
+    @Override
+    public boolean isRequestedSessionIdFromURL() {
+        return false;
+    }
+
+    @Deprecated
+    @Override
+    public boolean isRequestedSessionIdFromUrl() {
+        return false;
+    }
+
+    @Override
+    public boolean authenticate(HttpServletResponse response) {
+        return false;
+    }
+
+    @Override
+    public void login(String username, String password) {
+    }
+
+    @Override
+    public void logout() {
+    }
+
+    @Override
+    public @Nullable Collection<Part> getParts() {
+        return null;
+    }
+
+    @Override
+    public @Nullable Part getPart(String name) {
+        return null;
+    }
+
+    @Override
+    public @Nullable <T extends HttpUpgradeHandler> T upgrade(Class<T> handlerClass) {
+        return null;
+    }
+
+    @Override
+    public @Nullable Object getAttribute(String name) {
+        return null;
+    }
+
+    @Override
+    public @Nullable Enumeration<String> getAttributeNames() {
+        return null;
+    }
+
+    @Override
+    public @Nullable String getCharacterEncoding() {
+        return null;
+    }
+
+    @Override
+    public void setCharacterEncoding(String env) {
+    }
+
+    @Override
+    public int getContentLength() {
+        return 0;
+    }
+
+    @Override
+    public long getContentLengthLong() {
+        return 0;
+    }
+
+    @Override
+    public @Nullable String getContentType() {
+        return null;
+    }
+
+    @Override
+    public @Nullable ServletInputStream getInputStream() {
+        return null;
+    }
+
+    @Override
+    public @Nullable String getParameter(String name) {
+        return null;
+    }
+
+    @Override
+    public @Nullable Enumeration<String> getParameterNames() {
+        return null;
+    }
+
+    @Override
+    public @Nullable String[] getParameterValues(String name) {
+        return null;
+    }
+
+    @Override
+    public @Nullable Map<String, String[]> getParameterMap() {
+        return null;
+    }
+
+    @Override
+    public @Nullable String getProtocol() {
+        return null;
+    }
+
+    @Override
+    public @Nullable String getScheme() {
+        return null;
+    }
+
+    @Override
+    public @Nullable String getServerName() {
+        return null;
+    }
+
+    @Override
+    public int getServerPort() {
+        return 0;
+    }
+
+    @Override
+    public @Nullable BufferedReader getReader() {
+        return null;
+    }
+
+    @Override
+    public @Nullable String getRemoteAddr() {
+        return null;
+    }
+
+    @Override
+    public @Nullable String getRemoteHost() {
+        return null;
+    }
+
+    @Override
+    public void setAttribute(String name, Object o) {
+    }
+
+    @Override
+    public void removeAttribute(String name) {
+    }
+
+    @Override
+    public @Nullable Locale getLocale() {
+        return null;
+    }
+
+    @Override
+    public @Nullable Enumeration<Locale> getLocales() {
+        return null;
+    }
+
+    @Override
+    public boolean isSecure() {
+        return false;
+    }
+
+    @Override
+    public @Nullable RequestDispatcher getRequestDispatcher(String path) {
+        return null;
+    }
+
+    @Deprecated
+    @Override
+    public @Nullable String getRealPath(String path) {
+        return null;
+    }
+
+    @Override
+    public int getRemotePort() {
+        return 0;
+    }
+
+    @Override
+    public @Nullable String getLocalName() {
+        return null;
+    }
+
+    @Override
+    public @Nullable String getLocalAddr() {
+        return null;
+    }
+
+    @Override
+    public int getLocalPort() {
+        return 0;
+    }
+
+    @Override
+    public @Nullable ServletContext getServletContext() {
+        return null;
+    }
+
+    @Override
+    public @Nullable AsyncContext startAsync() throws IllegalStateException {
+        return null;
+    }
+
+    @Override
+    public @Nullable AsyncContext
+    startAsync(ServletRequest servletRequest, ServletResponse servletResponse)
+            throws IllegalStateException {
+        return null;
+    }
+
+    @Override
+    public boolean isAsyncStarted() {
+        return false;
+    }
+
+    @Override
+    public boolean isAsyncSupported() {
+        return false;
+    }
+
+    @Override
+    public @Nullable AsyncContext getAsyncContext() {
+        return null;
+    }
+
+    @Override
+    public @Nullable DispatcherType getDispatcherType() {
+        return null;
+    }
+}
diff --git a/testutil-web/src/main/java/io/spine/web/given/MockedResponse.java b/testutil-web/src/main/java/io/spine/web/given/MockedResponse.java
new file mode 100644
index 000000000..7f9c9e1eb
--- /dev/null
+++ b/testutil-web/src/main/java/io/spine/web/given/MockedResponse.java
@@ -0,0 +1,208 @@
+/*
+ * Copyright (c) 2000-2020 TeamDev Ltd. All rights reserved.
+ * TeamDev PROPRIETARY and CONFIDENTIAL.
+ * Use is subject to license terms.
+ */
+
+package io.spine.web.given;
+
+import com.google.common.collect.ImmutableList;
+import org.checkerframework.checker.nullness.qual.Nullable;
+
+import javax.servlet.ServletOutputStream;
+import javax.servlet.http.Cookie;
+import javax.servlet.http.HttpServletResponse;
+import java.io.PrintWriter;
+import java.util.Collection;
+import java.util.Locale;
+
+/**
+ * A mock servlet request that returns pre-defined request URI.
+ *
+ * @apiNote Some of the methods are marked as {@linkplain Deprecated deprecated} to avoid
+ *         the deprecation warnings, as their {@code super} methods are marked as such.
+ */
+public class MockedResponse implements HttpServletResponse {
+
+    private final int status;
+
+    private MockedResponse(int status) {
+        this.status = status;
+    }
+
+    /**
+     * Creates a mock response that always returns the given status.
+     */
+    public static MockedResponse create(int status) {
+        return new MockedResponse(status);
+    }
+
+    @Override
+    public int getStatus() {
+        return status;
+    }
+
+    // All methods below are intentionally no-op.
+
+    @Override
+    public void addCookie(Cookie cookie) {
+    }
+
+    @Override
+    public boolean containsHeader(String name) {
+        return false;
+    }
+
+    @Override
+    public @Nullable String encodeURL(String url) {
+        return null;
+    }
+
+    @Override
+    public @Nullable String encodeRedirectURL(String url) {
+        return null;
+    }
+
+    @Deprecated
+    @Override
+    public @Nullable String encodeUrl(String url) {
+        return null;
+    }
+
+    @Deprecated
+    @Override
+    public @Nullable String encodeRedirectUrl(String url) {
+        return null;
+    }
+
+    @Override
+    public void sendError(int sc, String msg) {
+    }
+
+    @Override
+    public void sendError(int sc) {
+    }
+
+    @Override
+    public void sendRedirect(String location) {
+    }
+
+    @Override
+    public void setDateHeader(String name, long date) {
+    }
+
+    @Override
+    public void addDateHeader(String name, long date) {
+    }
+
+    @Override
+    public void setHeader(String name, String value) {
+    }
+
+    @Override
+    public void addHeader(String name, String value) {
+    }
+
+    @Override
+    public void setIntHeader(String name, int value) {
+    }
+
+    @Override
+    public void addIntHeader(String name, int value) {
+    }
+
+    @Override
+    public void setStatus(int sc) {
+    }
+
+    @Deprecated
+    @Override
+    public void setStatus(int sc, String sm) {
+    }
+
+    @Override
+    public @Nullable String getHeader(String name) {
+        return null;
+    }
+
+    @Override
+    public Collection<String> getHeaders(String name) {
+        return ImmutableList.of();
+    }
+
+    @Override
+    public Collection<String> getHeaderNames() {
+        return ImmutableList.of();
+    }
+
+    @Override
+    public @Nullable String getCharacterEncoding() {
+        return null;
+    }
+
+    @Override
+    public @Nullable String getContentType() {
+        return null;
+    }
+
+    @Override
+    public @Nullable ServletOutputStream getOutputStream() {
+        return null;
+    }
+
+    @Override
+    public @Nullable PrintWriter getWriter() {
+        return null;
+    }
+
+    @Override
+    public void setCharacterEncoding(String charset) {
+    }
+
+    @Override
+    public void setContentLength(int len) {
+    }
+
+    @Override
+    public void setContentLengthLong(long len) {
+    }
+
+    @Override
+    public void setContentType(String type) {
+    }
+
+    @Override
+    public void setBufferSize(int size) {
+    }
+
+    @Override
+    public int getBufferSize() {
+        return 0;
+    }
+
+    @Override
+    public void flushBuffer() {
+    }
+
+    @Override
+    public void resetBuffer() {
+    }
+
+    @Override
+    public boolean isCommitted() {
+        return false;
+    }
+
+    @Override
+    public void reset() {
+    }
+
+    @Override
+    public void setLocale(Locale loc) {
+    }
+
+    @Override
+    public @Nullable Locale getLocale() {
+        return null;
+    }
+}

From 5a74370d5f86ac19a0792fef82be39877a38a1fa Mon Sep 17 00:00:00 2001
From: Yuri Sergiichuk <yuri.sergiichuk@teamdev.com>
Date: Fri, 4 Dec 2020 16:41:23 +0200
Subject: [PATCH 07/41] Convert to interfaces.

---
 .../io/spine/web/given/MockedRequest.java     | 173 ++++++++----------
 .../io/spine/web/given/MockedResponse.java    | 100 +++++-----
 2 files changed, 117 insertions(+), 156 deletions(-)

diff --git a/testutil-web/src/main/java/io/spine/web/given/MockedRequest.java b/testutil-web/src/main/java/io/spine/web/given/MockedRequest.java
index ef746d35c..7eefb9ed8 100644
--- a/testutil-web/src/main/java/io/spine/web/given/MockedRequest.java
+++ b/testutil-web/src/main/java/io/spine/web/given/MockedRequest.java
@@ -6,7 +6,6 @@
 
 package io.spine.web.given;
 
-import com.google.common.collect.ImmutableMap;
 import org.checkerframework.checker.nullness.qual.Nullable;
 
 import javax.servlet.AsyncContext;
@@ -30,378 +29,356 @@
 import java.util.Map;
 
 /**
- * A mock servlet request that returns a pre-defined request URI and headers.
+ * A mocked no-op servlet request that returns.
  *
  * @apiNote Some of the methods are marked as {@linkplain Deprecated deprecated} to avoid
  *         the deprecation warnings, as their {@code super} methods are marked as such.
  */
-public class MockedRequest implements HttpServletRequest {
-
-    private final ImmutableMap<String, String> headers;
-    private final String requestUri;
-
-    private MockedRequest(Map<String, String> headers, String uri) {
-        this.headers = ImmutableMap.copyOf(headers);
-        this.requestUri = uri;
-    }
-
-    /**
-     * Creates a new mock request.
-     */
-    public static ServletRequest create(String requestUri) {
-        return create(ImmutableMap.of(), requestUri);
-    }
-
-    /**
-     * Creates a new mock request with headers.
-     */
-    public static ServletRequest create(Map<String, String> headers, String requestUri) {
-        return new MockedRequest(headers, requestUri);
-    }
+public interface MockedRequest extends HttpServletRequest {
 
     @Override
-    public String getRequestURI() {
-        return requestUri;
+    default @Nullable String getRequestURI() {
+        return null;
     }
 
-    // All methods below are intentionally no-op.
-
     @Override
-    public @Nullable String getAuthType() {
+    default @Nullable String getAuthType() {
         return null;
     }
 
     @Override
-    public @Nullable Cookie[] getCookies() {
+    @SuppressWarnings("ReturnOfNull") // we're explicitly returning `null`.
+    default @Nullable Cookie[] getCookies() {
         return null;
     }
 
     @Override
-    public long getDateHeader(String name) {
+    default long getDateHeader(String name) {
         return 0;
     }
 
     @Override
-    public @Nullable String getHeader(String name) {
-        return headers.get(name);
+    default @Nullable String getHeader(String name) {
+        return null;
     }
 
     @Override
-    public @Nullable Enumeration<String> getHeaders(String name) {
+    default @Nullable Enumeration<String> getHeaders(String name) {
         return null;
     }
 
     @Override
-    public @Nullable Enumeration<String> getHeaderNames() {
+    default @Nullable Enumeration<String> getHeaderNames() {
         return null;
     }
 
     @Override
-    public int getIntHeader(String name) {
+    default int getIntHeader(String name) {
         return 0;
     }
 
     @Override
-    public @Nullable String getMethod() {
+    default @Nullable String getMethod() {
         return null;
     }
 
     @Override
-    public @Nullable String getPathInfo() {
+    default @Nullable String getPathInfo() {
         return null;
     }
 
     @Override
-    public @Nullable String getPathTranslated() {
+    default @Nullable String getPathTranslated() {
         return null;
     }
 
     @Override
-    public @Nullable String getContextPath() {
+    default @Nullable String getContextPath() {
         return null;
     }
 
     @Override
-    public @Nullable String getQueryString() {
+    default @Nullable String getQueryString() {
         return null;
     }
 
     @Override
-    public @Nullable String getRemoteUser() {
+    default @Nullable String getRemoteUser() {
         return null;
     }
 
     @Override
-    public boolean isUserInRole(String role) {
+    default boolean isUserInRole(String role) {
         return false;
     }
 
     @Override
-    public @Nullable Principal getUserPrincipal() {
+    default @Nullable Principal getUserPrincipal() {
         return null;
     }
 
     @Override
-    public @Nullable String getRequestedSessionId() {
+    default @Nullable String getRequestedSessionId() {
         return null;
     }
 
     @Override
-    public @Nullable StringBuffer getRequestURL() {
+    default @Nullable StringBuffer getRequestURL() {
         return null;
     }
 
     @Override
-    public @Nullable String getServletPath() {
+    default @Nullable String getServletPath() {
         return null;
     }
 
     @Override
-    public @Nullable HttpSession getSession(boolean create) {
+    default @Nullable HttpSession getSession(boolean create) {
         return null;
     }
 
     @Override
-    public @Nullable HttpSession getSession() {
+    default @Nullable HttpSession getSession() {
         return null;
     }
 
     @Override
-    public @Nullable String changeSessionId() {
+    default @Nullable String changeSessionId() {
         return null;
     }
 
     @Override
-    public boolean isRequestedSessionIdValid() {
+    default boolean isRequestedSessionIdValid() {
         return false;
     }
 
     @Override
-    public boolean isRequestedSessionIdFromCookie() {
+    default boolean isRequestedSessionIdFromCookie() {
         return false;
     }
 
     @Override
-    public boolean isRequestedSessionIdFromURL() {
+    default boolean isRequestedSessionIdFromURL() {
         return false;
     }
 
     @Deprecated
     @Override
-    public boolean isRequestedSessionIdFromUrl() {
+    default boolean isRequestedSessionIdFromUrl() {
         return false;
     }
 
     @Override
-    public boolean authenticate(HttpServletResponse response) {
+    default boolean authenticate(HttpServletResponse response) {
         return false;
     }
 
     @Override
-    public void login(String username, String password) {
+    default void login(String username, String password) {
     }
 
     @Override
-    public void logout() {
+    default void logout() {
     }
 
     @Override
-    public @Nullable Collection<Part> getParts() {
+    default @Nullable Collection<Part> getParts() {
         return null;
     }
 
     @Override
-    public @Nullable Part getPart(String name) {
+    default @Nullable Part getPart(String name) {
         return null;
     }
 
     @Override
-    public @Nullable <T extends HttpUpgradeHandler> T upgrade(Class<T> handlerClass) {
+    default @Nullable <T extends HttpUpgradeHandler> T upgrade(Class<T> handlerClass) {
         return null;
     }
 
     @Override
-    public @Nullable Object getAttribute(String name) {
+    default @Nullable Object getAttribute(String name) {
         return null;
     }
 
     @Override
-    public @Nullable Enumeration<String> getAttributeNames() {
+    default @Nullable Enumeration<String> getAttributeNames() {
         return null;
     }
 
     @Override
-    public @Nullable String getCharacterEncoding() {
+    default @Nullable String getCharacterEncoding() {
         return null;
     }
 
     @Override
-    public void setCharacterEncoding(String env) {
+    default void setCharacterEncoding(String env) {
     }
 
     @Override
-    public int getContentLength() {
+    default int getContentLength() {
         return 0;
     }
 
     @Override
-    public long getContentLengthLong() {
+    default long getContentLengthLong() {
         return 0;
     }
 
     @Override
-    public @Nullable String getContentType() {
+    default @Nullable String getContentType() {
         return null;
     }
 
     @Override
-    public @Nullable ServletInputStream getInputStream() {
+    default @Nullable ServletInputStream getInputStream() {
         return null;
     }
 
     @Override
-    public @Nullable String getParameter(String name) {
+    default @Nullable String getParameter(String name) {
         return null;
     }
 
     @Override
-    public @Nullable Enumeration<String> getParameterNames() {
+    default @Nullable Enumeration<String> getParameterNames() {
         return null;
     }
 
     @Override
-    public @Nullable String[] getParameterValues(String name) {
+    @SuppressWarnings("ReturnOfNull") // we're explicitly returning `null`.
+    default @Nullable String[] getParameterValues(String name) {
         return null;
     }
 
     @Override
-    public @Nullable Map<String, String[]> getParameterMap() {
+    default @Nullable Map<String, String[]> getParameterMap() {
         return null;
     }
 
     @Override
-    public @Nullable String getProtocol() {
+    default @Nullable String getProtocol() {
         return null;
     }
 
     @Override
-    public @Nullable String getScheme() {
+    default @Nullable String getScheme() {
         return null;
     }
 
     @Override
-    public @Nullable String getServerName() {
+    default @Nullable String getServerName() {
         return null;
     }
 
     @Override
-    public int getServerPort() {
+    default int getServerPort() {
         return 0;
     }
 
     @Override
-    public @Nullable BufferedReader getReader() {
+    default @Nullable BufferedReader getReader() {
         return null;
     }
 
     @Override
-    public @Nullable String getRemoteAddr() {
+    default @Nullable String getRemoteAddr() {
         return null;
     }
 
     @Override
-    public @Nullable String getRemoteHost() {
+    default @Nullable String getRemoteHost() {
         return null;
     }
 
     @Override
-    public void setAttribute(String name, Object o) {
+    default void setAttribute(String name, Object o) {
     }
 
     @Override
-    public void removeAttribute(String name) {
+    default void removeAttribute(String name) {
     }
 
     @Override
-    public @Nullable Locale getLocale() {
+    default @Nullable Locale getLocale() {
         return null;
     }
 
     @Override
-    public @Nullable Enumeration<Locale> getLocales() {
+    default @Nullable Enumeration<Locale> getLocales() {
         return null;
     }
 
     @Override
-    public boolean isSecure() {
+    default boolean isSecure() {
         return false;
     }
 
     @Override
-    public @Nullable RequestDispatcher getRequestDispatcher(String path) {
+    default @Nullable RequestDispatcher getRequestDispatcher(String path) {
         return null;
     }
 
     @Deprecated
     @Override
-    public @Nullable String getRealPath(String path) {
+    default @Nullable String getRealPath(String path) {
         return null;
     }
 
     @Override
-    public int getRemotePort() {
+    default int getRemotePort() {
         return 0;
     }
 
     @Override
-    public @Nullable String getLocalName() {
+    default @Nullable String getLocalName() {
         return null;
     }
 
     @Override
-    public @Nullable String getLocalAddr() {
+    default @Nullable String getLocalAddr() {
         return null;
     }
 
     @Override
-    public int getLocalPort() {
+    default int getLocalPort() {
         return 0;
     }
 
     @Override
-    public @Nullable ServletContext getServletContext() {
+    default @Nullable ServletContext getServletContext() {
         return null;
     }
 
     @Override
-    public @Nullable AsyncContext startAsync() throws IllegalStateException {
+    default @Nullable AsyncContext startAsync() throws IllegalStateException {
         return null;
     }
 
     @Override
-    public @Nullable AsyncContext
+    default @Nullable AsyncContext
     startAsync(ServletRequest servletRequest, ServletResponse servletResponse)
             throws IllegalStateException {
         return null;
     }
 
     @Override
-    public boolean isAsyncStarted() {
+    default boolean isAsyncStarted() {
         return false;
     }
 
     @Override
-    public boolean isAsyncSupported() {
+    default boolean isAsyncSupported() {
         return false;
     }
 
     @Override
-    public @Nullable AsyncContext getAsyncContext() {
+    default @Nullable AsyncContext getAsyncContext() {
         return null;
     }
 
     @Override
-    public @Nullable DispatcherType getDispatcherType() {
+    default @Nullable DispatcherType getDispatcherType() {
         return null;
     }
 }
diff --git a/testutil-web/src/main/java/io/spine/web/given/MockedResponse.java b/testutil-web/src/main/java/io/spine/web/given/MockedResponse.java
index 7f9c9e1eb..24ce2b0f7 100644
--- a/testutil-web/src/main/java/io/spine/web/given/MockedResponse.java
+++ b/testutil-web/src/main/java/io/spine/web/given/MockedResponse.java
@@ -6,7 +6,6 @@
 
 package io.spine.web.given;
 
-import com.google.common.collect.ImmutableList;
 import org.checkerframework.checker.nullness.qual.Nullable;
 
 import javax.servlet.ServletOutputStream;
@@ -17,192 +16,177 @@
 import java.util.Locale;
 
 /**
- * A mock servlet request that returns pre-defined request URI.
+ * A mocked no-op servlet response.
  *
  * @apiNote Some of the methods are marked as {@linkplain Deprecated deprecated} to avoid
  *         the deprecation warnings, as their {@code super} methods are marked as such.
  */
-public class MockedResponse implements HttpServletResponse {
-
-    private final int status;
-
-    private MockedResponse(int status) {
-        this.status = status;
-    }
-
-    /**
-     * Creates a mock response that always returns the given status.
-     */
-    public static MockedResponse create(int status) {
-        return new MockedResponse(status);
-    }
+public interface MockedResponse extends HttpServletResponse {
 
     @Override
-    public int getStatus() {
-        return status;
+    default int getStatus() {
+        return 0;
     }
 
-    // All methods below are intentionally no-op.
-
     @Override
-    public void addCookie(Cookie cookie) {
+    default void addCookie(Cookie cookie) {
     }
 
     @Override
-    public boolean containsHeader(String name) {
+    default boolean containsHeader(String name) {
         return false;
     }
 
     @Override
-    public @Nullable String encodeURL(String url) {
+    default @Nullable String encodeURL(String url) {
         return null;
     }
 
     @Override
-    public @Nullable String encodeRedirectURL(String url) {
+    default @Nullable String encodeRedirectURL(String url) {
         return null;
     }
 
     @Deprecated
     @Override
-    public @Nullable String encodeUrl(String url) {
+    default @Nullable String encodeUrl(String url) {
         return null;
     }
 
     @Deprecated
     @Override
-    public @Nullable String encodeRedirectUrl(String url) {
+    default @Nullable String encodeRedirectUrl(String url) {
         return null;
     }
 
     @Override
-    public void sendError(int sc, String msg) {
+    default void sendError(int sc, String msg) {
     }
 
     @Override
-    public void sendError(int sc) {
+    default void sendError(int sc) {
     }
 
     @Override
-    public void sendRedirect(String location) {
+    default void sendRedirect(String location) {
     }
 
     @Override
-    public void setDateHeader(String name, long date) {
+    default void setDateHeader(String name, long date) {
     }
 
     @Override
-    public void addDateHeader(String name, long date) {
+    default void addDateHeader(String name, long date) {
     }
 
     @Override
-    public void setHeader(String name, String value) {
+    default void setHeader(String name, String value) {
     }
 
     @Override
-    public void addHeader(String name, String value) {
+    default void addHeader(String name, String value) {
     }
 
     @Override
-    public void setIntHeader(String name, int value) {
+    default void setIntHeader(String name, int value) {
     }
 
     @Override
-    public void addIntHeader(String name, int value) {
+    default void addIntHeader(String name, int value) {
     }
 
     @Override
-    public void setStatus(int sc) {
+    default void setStatus(int sc) {
     }
 
     @Deprecated
     @Override
-    public void setStatus(int sc, String sm) {
+    default void setStatus(int sc, String sm) {
     }
 
     @Override
-    public @Nullable String getHeader(String name) {
+    default @Nullable String getHeader(String name) {
         return null;
     }
 
     @Override
-    public Collection<String> getHeaders(String name) {
-        return ImmutableList.of();
+    default @Nullable Collection<String> getHeaders(String name) {
+        return null;
     }
 
     @Override
-    public Collection<String> getHeaderNames() {
-        return ImmutableList.of();
+    default @Nullable Collection<String> getHeaderNames() {
+        return null;
     }
 
     @Override
-    public @Nullable String getCharacterEncoding() {
+    default @Nullable String getCharacterEncoding() {
         return null;
     }
 
     @Override
-    public @Nullable String getContentType() {
+    default @Nullable String getContentType() {
         return null;
     }
 
     @Override
-    public @Nullable ServletOutputStream getOutputStream() {
+    default @Nullable ServletOutputStream getOutputStream() {
         return null;
     }
 
     @Override
-    public @Nullable PrintWriter getWriter() {
+    default @Nullable PrintWriter getWriter() {
         return null;
     }
 
     @Override
-    public void setCharacterEncoding(String charset) {
+    default void setCharacterEncoding(String charset) {
     }
 
     @Override
-    public void setContentLength(int len) {
+    default void setContentLength(int len) {
     }
 
     @Override
-    public void setContentLengthLong(long len) {
+    default void setContentLengthLong(long len) {
     }
 
     @Override
-    public void setContentType(String type) {
+    default void setContentType(String type) {
     }
 
     @Override
-    public void setBufferSize(int size) {
+    default void setBufferSize(int size) {
     }
 
     @Override
-    public int getBufferSize() {
+    default int getBufferSize() {
         return 0;
     }
 
     @Override
-    public void flushBuffer() {
+    default void flushBuffer() {
     }
 
     @Override
-    public void resetBuffer() {
+    default void resetBuffer() {
     }
 
     @Override
-    public boolean isCommitted() {
+    default boolean isCommitted() {
         return false;
     }
 
     @Override
-    public void reset() {
+    default void reset() {
     }
 
     @Override
-    public void setLocale(Locale loc) {
+    default void setLocale(Locale loc) {
     }
 
     @Override
-    public @Nullable Locale getLocale() {
+    default @Nullable Locale getLocale() {
         return null;
     }
 }

From a31f91f6dca34cff92f85c1fde901902b5649d58 Mon Sep 17 00:00:00 2001
From: Yuri Sergiichuk <yuri.sergiichuk@teamdev.com>
Date: Fri, 4 Dec 2020 17:00:58 +0200
Subject: [PATCH 08/41] Introduce fixed content request and response.

---
 .../spine/web/given/FixedContentRequest.java  | 148 ++++++++++++++++++
 .../spine/web/given/FixedContentResponse.java | 110 +++++++++++++
 2 files changed, 258 insertions(+)
 create mode 100644 testutil-web/src/main/java/io/spine/web/given/FixedContentRequest.java
 create mode 100644 testutil-web/src/main/java/io/spine/web/given/FixedContentResponse.java

diff --git a/testutil-web/src/main/java/io/spine/web/given/FixedContentRequest.java b/testutil-web/src/main/java/io/spine/web/given/FixedContentRequest.java
new file mode 100644
index 000000000..f11740f28
--- /dev/null
+++ b/testutil-web/src/main/java/io/spine/web/given/FixedContentRequest.java
@@ -0,0 +1,148 @@
+/*
+ * Copyright 2020, TeamDev. All rights reserved.
+ *
+ * Redistribution and use in source and/or binary forms, with or without
+ * modification, must retain the above copyright notice and the following
+ * disclaimer.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+package io.spine.web.given;
+
+import com.google.common.collect.ImmutableMap;
+import com.google.common.collect.ImmutableSet;
+import com.google.common.net.MediaType;
+import org.checkerframework.checker.nullness.qual.Nullable;
+
+import java.io.BufferedReader;
+import java.io.ByteArrayInputStream;
+import java.io.InputStreamReader;
+import java.util.Enumeration;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+import static com.google.common.collect.Iterators.asEnumeration;
+import static com.google.common.collect.Iterators.singletonIterator;
+import static java.nio.charset.Charset.defaultCharset;
+import static java.util.Collections.emptyIterator;
+
+/**
+ * A mocked servlet request with pre-defined {@code content}, {@code type} and {@code headers}.
+ *
+ * <p>In most cases this implementation should be sufficient enough for local tests.
+ */
+@SuppressWarnings("UnstableApiUsage") // we're OK using Guava's beta APIs
+public final class FixedContentRequest implements MockedRequest {
+
+    private static final String CONTENT_TYPE = "Content-Type";
+
+    private final ImmutableMap<String, String> headers;
+    private final byte[] content;
+    private final MediaType type;
+
+    private FixedContentRequest(ImmutableMap<String, String> headers,
+                                byte[] content,
+                                MediaType type) {
+        this.headers = headers;
+        this.content = content;
+        this.type = type;
+    }
+
+    /**
+     * Creates a new mocked request with specified {@code content} and default
+     * {@linkplain MediaType#ANY_TYPE any} type.
+     */
+    public static FixedContentRequest create(String content) {
+        checkNotNull(content);
+        return create(content, MediaType.ANY_TYPE);
+    }
+
+    /**
+     * Creates a new mocked request with specified {@code content} and {@code type}.
+     */
+    public static FixedContentRequest create(String content, MediaType type) {
+        checkNotNull(content);
+        checkNotNull(type);
+        return create(content, type, contentTypeHeader(type));
+    }
+
+    /**
+     * Creates a new mocked request with specified {@code content}, {@code type}
+     * and {@code headers}.
+     */
+    public static FixedContentRequest create(String content,
+                                             MediaType type,
+                                             ImmutableMap<String, String> headers) {
+        checkNotNull(content);
+        checkNotNull(type);
+        checkNotNull(headers);
+        return create(content.getBytes(defaultCharset()), type, headers);
+    }
+
+    /**
+     * Creates a new mocked request with specified {@code content}, {@code type}
+     * and {@code headers}.
+     */
+    public static FixedContentRequest create(byte[] content,
+                                             MediaType type,
+                                             ImmutableMap<String, String> headers) {
+        checkNotNull(content);
+        checkNotNull(type);
+        checkNotNull(headers);
+        return new FixedContentRequest(headers, content, type);
+    }
+
+    private static ImmutableMap<String, String> contentTypeHeader(MediaType type) {
+        return ImmutableMap.of(CONTENT_TYPE, type.toString());
+    }
+
+    @Override
+    public @Nullable String getHeader(String name) {
+        return headers.get(name);
+    }
+
+    @Override
+    public Enumeration<String> getHeaders(String name) {
+        String result = headers.get(name);
+        if (result == null) {
+            return asEnumeration(emptyIterator());
+        }
+        return asEnumeration(singletonIterator(result));
+    }
+
+    @Override
+    public Enumeration<String> getHeaderNames() {
+        ImmutableSet<String> names = headers.keySet();
+        return asEnumeration(names.iterator());
+    }
+
+    @Override
+    public int getContentLength() {
+        return content.length;
+    }
+
+    @Override
+    public long getContentLengthLong() {
+        return content.length;
+    }
+
+    @Override
+    public @Nullable String getContentType() {
+        return type.toString();
+    }
+
+    @Override
+    public BufferedReader getReader() {
+        return new BufferedReader(new InputStreamReader(new ByteArrayInputStream(content)));
+    }
+}
diff --git a/testutil-web/src/main/java/io/spine/web/given/FixedContentResponse.java b/testutil-web/src/main/java/io/spine/web/given/FixedContentResponse.java
new file mode 100644
index 000000000..50800aabb
--- /dev/null
+++ b/testutil-web/src/main/java/io/spine/web/given/FixedContentResponse.java
@@ -0,0 +1,110 @@
+/*
+ * Copyright 2020, TeamDev. All rights reserved.
+ *
+ * Redistribution and use in source and/or binary forms, with or without
+ * modification, must retain the above copyright notice and the following
+ * disclaimer.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+package io.spine.web.given;
+
+import com.google.common.collect.ImmutableMap;
+import com.google.common.collect.ImmutableSet;
+import org.checkerframework.checker.nullness.qual.Nullable;
+
+import java.io.PrintWriter;
+import java.io.Writer;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+
+/**
+ * A mocked servlet response with pre-defined {@code writer}, {@code status} and {@code headers}.
+ *
+ * <p>In most cases this implementation should be sufficient enough for local tests.
+ */
+public final class FixedContentResponse implements MockedResponse {
+
+    private static final int SUCCESS = 200;
+
+    private final ImmutableMap<String, String> headers;
+    private final int status;
+    private final Writer writer;
+
+    private FixedContentResponse(ImmutableMap<String, String> headers,
+                                 Writer writer,
+                                 int status) {
+        this.headers = headers;
+        this.writer = writer;
+        this.status = status;
+    }
+
+    /**
+     * Creates a new mocked response with specified {@code writer} and default
+     * {@code 200} status.
+     */
+    public static FixedContentResponse create(Writer writer) {
+        checkNotNull(writer);
+        return create(writer, SUCCESS);
+    }
+
+    /**
+     * Creates a new mocked response with specified {@code writer} and {@code status}.
+     */
+    public static FixedContentResponse create(Writer writer, int status) {
+        checkNotNull(writer);
+        return create(writer, status, ImmutableMap.of());
+    }
+
+    /**
+     * Creates a new mocked response with specified {@code writer}, {@code status}
+     * and {@code headers}.
+     */
+    public static FixedContentResponse create(Writer writer,
+                                              int status,
+                                              ImmutableMap<String, String> headers) {
+        checkNotNull(writer);
+        checkNotNull(headers);
+        return new FixedContentResponse(headers, writer, status);
+    }
+
+    @Override
+    public int getStatus() {
+        return status;
+    }
+
+    @Override
+    public @Nullable String getHeader(String name) {
+        return headers.get(name);
+    }
+
+    @Override
+    public ImmutableSet<String> getHeaders(String name) {
+        String result = headers.get(name);
+        if (result == null) {
+            return ImmutableSet.of();
+        }
+        return ImmutableSet.of(result);
+    }
+
+    @Override
+    public ImmutableSet<String> getHeaderNames() {
+        return headers.keySet();
+    }
+
+    @Override
+    public PrintWriter getWriter() {
+        return new PrintWriter(writer);
+    }
+}

From 8a3b8aa2446500f7ea3c6202191892b43479f111 Mon Sep 17 00:00:00 2001
From: Yuri Sergiichuk <yuri.sergiichuk@teamdev.com>
Date: Fri, 4 Dec 2020 17:14:30 +0200
Subject: [PATCH 09/41] Use servlet constant.

---
 .../main/java/io/spine/web/given/FixedContentResponse.java  | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/testutil-web/src/main/java/io/spine/web/given/FixedContentResponse.java b/testutil-web/src/main/java/io/spine/web/given/FixedContentResponse.java
index 50800aabb..87caae9bf 100644
--- a/testutil-web/src/main/java/io/spine/web/given/FixedContentResponse.java
+++ b/testutil-web/src/main/java/io/spine/web/given/FixedContentResponse.java
@@ -36,8 +36,6 @@
  */
 public final class FixedContentResponse implements MockedResponse {
 
-    private static final int SUCCESS = 200;
-
     private final ImmutableMap<String, String> headers;
     private final int status;
     private final Writer writer;
@@ -52,11 +50,11 @@ private FixedContentResponse(ImmutableMap<String, String> headers,
 
     /**
      * Creates a new mocked response with specified {@code writer} and default
-     * {@code 200} status.
+     * {@linkplain #SC_OK OK} status.
      */
     public static FixedContentResponse create(Writer writer) {
         checkNotNull(writer);
-        return create(writer, SUCCESS);
+        return create(writer, SC_OK);
     }
 
     /**

From b139246711b4f2d46e573d0ae72380735706bf16 Mon Sep 17 00:00:00 2001
From: Yuri Sergiichuk <yuri.sergiichuk@teamdev.com>
Date: Fri, 4 Dec 2020 17:30:17 +0200
Subject: [PATCH 10/41] Use UTF8 as the default charset.

---
 .../java/io/spine/web/given/FixedContentRequest.java   | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/testutil-web/src/main/java/io/spine/web/given/FixedContentRequest.java b/testutil-web/src/main/java/io/spine/web/given/FixedContentRequest.java
index f11740f28..8b705c72b 100644
--- a/testutil-web/src/main/java/io/spine/web/given/FixedContentRequest.java
+++ b/testutil-web/src/main/java/io/spine/web/given/FixedContentRequest.java
@@ -28,12 +28,12 @@
 import java.io.BufferedReader;
 import java.io.ByteArrayInputStream;
 import java.io.InputStreamReader;
+import java.nio.charset.StandardCharsets;
 import java.util.Enumeration;
 
 import static com.google.common.base.Preconditions.checkNotNull;
 import static com.google.common.collect.Iterators.asEnumeration;
 import static com.google.common.collect.Iterators.singletonIterator;
-import static java.nio.charset.Charset.defaultCharset;
 import static java.util.Collections.emptyIterator;
 
 /**
@@ -86,7 +86,7 @@ public static FixedContentRequest create(String content,
         checkNotNull(content);
         checkNotNull(type);
         checkNotNull(headers);
-        return create(content.getBytes(defaultCharset()), type, headers);
+        return create(content.getBytes(StandardCharsets.UTF_8), type, headers);
     }
 
     /**
@@ -143,6 +143,10 @@ public long getContentLengthLong() {
 
     @Override
     public BufferedReader getReader() {
-        return new BufferedReader(new InputStreamReader(new ByteArrayInputStream(content)));
+        return new BufferedReader(
+                new InputStreamReader(
+                        new ByteArrayInputStream(content), StandardCharsets.UTF_8
+                )
+        );
     }
 }

From 8ef15dd4e5cf30de5a63f5000accb9d5a46cf7f9 Mon Sep 17 00:00:00 2001
From: Yuri Sergiichuk <yuri.sergiichuk@teamdev.com>
Date: Fri, 4 Dec 2020 17:30:53 +0200
Subject: [PATCH 11/41] Introduce a `SettableResponse` that allows verifying
 particular interactions done with a response.

---
 .../io/spine/web/given/SettableResponse.java  | 97 +++++++++++++++++++
 1 file changed, 97 insertions(+)
 create mode 100644 testutil-web/src/main/java/io/spine/web/given/SettableResponse.java

diff --git a/testutil-web/src/main/java/io/spine/web/given/SettableResponse.java b/testutil-web/src/main/java/io/spine/web/given/SettableResponse.java
new file mode 100644
index 000000000..dcabe8ddf
--- /dev/null
+++ b/testutil-web/src/main/java/io/spine/web/given/SettableResponse.java
@@ -0,0 +1,97 @@
+/*
+ * Copyright 2020, TeamDev. All rights reserved.
+ *
+ * Redistribution and use in source and/or binary forms, with or without
+ * modification, must retain the above copyright notice and the following
+ * disclaimer.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+package io.spine.web.given;
+
+import com.google.common.collect.ImmutableSet;
+import org.checkerframework.checker.nullness.qual.Nullable;
+
+import java.io.PrintWriter;
+import java.io.StringWriter;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Set;
+
+/**
+ * A mocked response whose {@code status} and {@code type} could be set.
+ */
+public final class SettableResponse implements MockedResponse {
+
+    private final StringWriter writer = new StringWriter();
+    private final Map<String, String> headers = new HashMap<>();
+    private String contentType = "";
+    private int status = -1;
+
+    @Override
+    public int getStatus() {
+        return status;
+    }
+
+    @Override
+    public @Nullable String getHeader(String name) {
+        return headers.get(name);
+    }
+
+    @Override
+    public void sendError(int sc) {
+        status = sc;
+    }
+
+    @Override
+    public void sendError(int sc, String msg) {
+        sendError(sc);
+    }
+
+    @Override
+    public void setContentType(String contentType) {
+        this.contentType = contentType;
+    }
+
+    @Override
+    public @Nullable String getContentType() {
+        return contentType;
+    }
+
+    @Override
+    public ImmutableSet<String> getHeaders(String name) {
+        String result = headers.get(name);
+        if (result == null) {
+            return ImmutableSet.of();
+        }
+        return ImmutableSet.of(result);
+    }
+
+    @Override
+    public Set<String> getHeaderNames() {
+        return headers.keySet();
+    }
+
+    @Override
+    public PrintWriter getWriter() {
+        return new PrintWriter(writer);
+    }
+
+    /**
+     * Returns the content of the associated response writer.
+     */
+    public String writerContent() {
+        return writer.toString();
+    }
+}

From c8d92e45d83f294c36267583f866b54f9df3120a Mon Sep 17 00:00:00 2001
From: Yuri Sergiichuk <yuri.sergiichuk@teamdev.com>
Date: Fri, 4 Dec 2020 17:31:11 +0200
Subject: [PATCH 12/41] Migrate from `mockito` to mocked response/request
 implementations

---
 .../spine/web/command/CommandServletTest.java | 11 +++----
 .../java/io/spine/web/given/Servlets.java     | 29 ++++++++-----------
 .../io/spine/web/query/QueryServletTest.java  | 19 +++++++-----
 3 files changed, 29 insertions(+), 30 deletions(-)

diff --git a/web/src/test/java/io/spine/web/command/CommandServletTest.java b/web/src/test/java/io/spine/web/command/CommandServletTest.java
index 35b3f79af..20ab0c65d 100644
--- a/web/src/test/java/io/spine/web/command/CommandServletTest.java
+++ b/web/src/test/java/io/spine/web/command/CommandServletTest.java
@@ -30,24 +30,25 @@
 import io.spine.testing.client.command.TestCommandMessage;
 import io.spine.testing.logging.MuteLogging;
 import io.spine.web.command.given.DetachedCommandServlet;
+import io.spine.web.given.SettableResponse;
 import org.junit.jupiter.api.DisplayName;
 import org.junit.jupiter.api.Test;
 
-import javax.servlet.http.HttpServletResponse;
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.io.ObjectOutput;
 import java.io.ObjectOutputStream;
 import java.io.StringWriter;
 
+import static com.google.common.truth.Truth.assertThat;
 import static io.spine.base.Identifier.newUuid;
 import static io.spine.web.given.Servlets.request;
 import static io.spine.web.given.Servlets.response;
+import static javax.servlet.http.HttpServletResponse.SC_BAD_REQUEST;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertThrows;
-import static org.mockito.Mockito.verify;
 
-@DisplayName("CommandServlet should")
+@DisplayName("`CommandServlet` should")
 class CommandServletTest {
 
     private static final CommandFactory commandFactory =
@@ -82,8 +83,8 @@ void testHandle() throws IOException {
     @DisplayName("respond 400 to an invalid command")
     void testInvalidCommand() throws IOException {
         CommandServlet servlet = new DetachedCommandServlet();
-        HttpServletResponse response = response(new StringWriter());
+        SettableResponse response = new SettableResponse();
         servlet.doPost(request(Time.currentTime()), response);
-        verify(response).sendError(400);
+        assertThat(response.getStatus()).isEqualTo(SC_BAD_REQUEST);
     }
 }
diff --git a/web/src/test/java/io/spine/web/given/Servlets.java b/web/src/test/java/io/spine/web/given/Servlets.java
index 745101a13..79e732c2d 100644
--- a/web/src/test/java/io/spine/web/given/Servlets.java
+++ b/web/src/test/java/io/spine/web/given/Servlets.java
@@ -20,20 +20,13 @@
 
 package io.spine.web.given;
 
+import com.google.common.net.MediaType;
 import com.google.protobuf.Message;
 import io.spine.json.Json;
 
-import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
-import java.io.BufferedReader;
-import java.io.IOException;
-import java.io.PrintWriter;
-import java.io.StringReader;
 import java.io.StringWriter;
 
-import static org.mockito.Mockito.mock;
-import static org.mockito.Mockito.when;
-
 /**
  * The factory of mock servlet API objects, such as requests and responses.
  */
@@ -45,16 +38,18 @@ public final class Servlets {
     private Servlets() {
     }
 
-    public static HttpServletRequest request(Message contents) throws IOException {
-        HttpServletRequest request = mock(HttpServletRequest.class);
-        String content = Json.toJson(contents);
-        when(request.getReader()).thenReturn(new BufferedReader(new StringReader(content)));
-        return request;
+    /**
+     * Creates a new request with the supplied {@code content}.
+     */
+    public static FixedContentRequest request(Message content) {
+        String json = Json.toJson(content);
+        return FixedContentRequest.create(json, MediaType.JSON_UTF_8);
     }
 
-    public static HttpServletResponse response(StringWriter writer) throws IOException {
-        HttpServletResponse response = mock(HttpServletResponse.class);
-        when(response.getWriter()).thenReturn(new PrintWriter(writer));
-        return response;
+    /**
+     * Creates a new response with the supplied {@code writer}.
+     */
+    public static HttpServletResponse response(StringWriter writer) {
+        return FixedContentResponse.create(writer);
     }
 }
diff --git a/web/src/test/java/io/spine/web/query/QueryServletTest.java b/web/src/test/java/io/spine/web/query/QueryServletTest.java
index ad0568498..c8edfe5e4 100644
--- a/web/src/test/java/io/spine/web/query/QueryServletTest.java
+++ b/web/src/test/java/io/spine/web/query/QueryServletTest.java
@@ -20,11 +20,14 @@
 
 package io.spine.web.query;
 
+import com.google.common.truth.Truth;
+import com.google.protobuf.Message;
 import io.spine.client.Query;
 import io.spine.client.QueryFactory;
 import io.spine.json.Json;
 import io.spine.testing.client.TestActorRequestFactory;
 import io.spine.testing.logging.MuteLogging;
+import io.spine.web.given.SettableResponse;
 import io.spine.web.query.given.QueryServletTestEnv.TestQueryServlet;
 import io.spine.web.test.Task;
 import io.spine.web.test.TaskId;
@@ -32,7 +35,6 @@
 import org.junit.jupiter.api.Test;
 
 import javax.servlet.http.HttpServletRequest;
-import javax.servlet.http.HttpServletResponse;
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.io.ObjectOutputStream;
@@ -42,10 +44,10 @@
 import static io.spine.base.Time.currentTime;
 import static io.spine.web.given.Servlets.request;
 import static io.spine.web.given.Servlets.response;
+import static javax.servlet.http.HttpServletResponse.SC_BAD_REQUEST;
 import static org.junit.jupiter.api.Assertions.assertThrows;
-import static org.mockito.Mockito.verify;
 
-@DisplayName("QueryServlet should")
+@DisplayName("`QueryServlet` should")
 class QueryServletTest {
 
     private static final QueryFactory queryFactory =
@@ -54,7 +56,7 @@ class QueryServletTest {
     @Test
     @DisplayName("throw UnsupportedOperationException when trying to serialize")
     void testFailToSerialize() throws IOException {
-        QueryServlet servlet = new TestQueryServlet();
+        QueryServlet<Message> servlet = new TestQueryServlet();
         ObjectOutputStream stream = new ObjectOutputStream(new ByteArrayOutputStream());
         assertThrows(UnsupportedOperationException.class, () -> stream.writeObject(servlet));
         stream.close();
@@ -68,7 +70,7 @@ void testHandle() throws IOException {
                 .setId(TaskId.generate())
                 .setDescription("some-task-description")
                 .build();
-        QueryServlet servlet = new TestQueryServlet(task);
+        QueryServlet<Message> servlet = new TestQueryServlet(task);
         StringWriter response = new StringWriter();
         Query query = queryFactory.all(Task.class);
         HttpServletRequest request = request(query);
@@ -81,9 +83,10 @@ void testHandle() throws IOException {
     @Test
     @DisplayName("respond 400 to an invalid query")
     void testInvalidQuery() throws IOException {
-        QueryServlet servlet = new TestQueryServlet();
-        HttpServletResponse response = response(new StringWriter());
+        QueryServlet<Message> servlet = new TestQueryServlet();
+        SettableResponse response = new SettableResponse();
         servlet.doPost(request(currentTime()), response);
-        verify(response).sendError(400);
+        Truth.assertThat(response.getStatus())
+             .isEqualTo(SC_BAD_REQUEST);
     }
 }

From 5c7c5a0d603f76810ab3eb733cf99900aac3cd30 Mon Sep 17 00:00:00 2001
From: Yuri Sergiichuk <yuri.sergiichuk@teamdev.com>
Date: Fri, 4 Dec 2020 17:35:19 +0200
Subject: [PATCH 13/41] Avoid Mockito usage.

---
 .../web/firebase/FirebaseClientFactoryTest.java   | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/firebase-web/src/test/java/io/spine/web/firebase/FirebaseClientFactoryTest.java b/firebase-web/src/test/java/io/spine/web/firebase/FirebaseClientFactoryTest.java
index 18fe92364..e8830822c 100644
--- a/firebase-web/src/test/java/io/spine/web/firebase/FirebaseClientFactoryTest.java
+++ b/firebase-web/src/test/java/io/spine/web/firebase/FirebaseClientFactoryTest.java
@@ -38,14 +38,14 @@
 import java.util.Date;
 
 import static com.google.common.truth.Truth.assertThat;
-import static org.mockito.Mockito.mock;
 
 @DisplayName("`FirebaseClientFactory` should")
 class FirebaseClientFactoryTest extends UtilityClassTest<FirebaseClientFactory> {
 
     private static final FirebaseCredentials CREDENTIALS = FirebaseCredentials.empty();
     private static final String FIREBASE_APP_NAME = FirebaseClientFactoryTest.class.getSimpleName();
-    private FirebaseDatabase database = mock(FirebaseDatabase.class);
+    private final FirebaseApp app = FirebaseApp.getInstance(FIREBASE_APP_NAME);
+    private FirebaseDatabase database;
 
     FirebaseClientFactoryTest() {
         super(FirebaseClientFactory.class);
@@ -66,19 +66,20 @@ static void initApp() {
 
     @Override
     protected void configure(NullPointerTester tester) {
-        tester.setDefault(FirebaseDatabase.class, mock(FirebaseDatabase.class))
+        tester.setDefault(FirebaseDatabase.class, FirebaseDatabase.getInstance(app))
               .setDefault(FirebaseCredentials.class, CREDENTIALS);
     }
 
     @BeforeEach
-    void configureFirebaseMock() {
-        FirebaseApp app = FirebaseApp.getInstance(FIREBASE_APP_NAME);
+    void configureDatabase() {
         database = FirebaseDatabase.getInstance(app);
     }
 
     @AfterEach
-    void cleanUp() {
-        ServerEnvironment.instance().reset();
+    void resetEnvironment() {
+        ServerEnvironment
+                .instance()
+                .reset();
     }
 
     @Test

From d5b5cc9a6e2b8da1a4419a65bd6938ad51d3fed8 Mon Sep 17 00:00:00 2001
From: Yuri Sergiichuk <yuri.sergiichuk@teamdev.com>
Date: Fri, 4 Dec 2020 18:13:35 +0200
Subject: [PATCH 14/41] Rename `TestFirebaseClient` into `MemoizedFirebase` and
 improve its API.

---
 .../spine/web/firebase/AsyncClientTest.java   | 12 +++----
 ...ebaseClient.java => MemoizedFirebase.java} | 35 +++++++++++++------
 2 files changed, 30 insertions(+), 17 deletions(-)
 rename firebase-web/src/test/java/io/spine/web/firebase/given/{TestFirebaseClient.java => MemoizedFirebase.java} (71%)

diff --git a/firebase-web/src/test/java/io/spine/web/firebase/AsyncClientTest.java b/firebase-web/src/test/java/io/spine/web/firebase/AsyncClientTest.java
index 11460e2af..6b3eda644 100644
--- a/firebase-web/src/test/java/io/spine/web/firebase/AsyncClientTest.java
+++ b/firebase-web/src/test/java/io/spine/web/firebase/AsyncClientTest.java
@@ -21,7 +21,7 @@
 package io.spine.web.firebase;
 
 import com.google.common.util.concurrent.Uninterruptibles;
-import io.spine.web.firebase.given.TestFirebaseClient;
+import io.spine.web.firebase.given.MemoizedFirebase;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.DisplayName;
 import org.junit.jupiter.api.Test;
@@ -37,7 +37,7 @@
 @DisplayName("Async Firebase client should")
 class AsyncClientTest {
 
-    private TestFirebaseClient delegate;
+    private MemoizedFirebase delegate;
     private NodePath path;
     private ExecutorService executor;
     private Duration latency;
@@ -45,7 +45,7 @@ class AsyncClientTest {
     @BeforeEach
     void setUp() {
         latency = ofSeconds(2);
-        delegate = TestFirebaseClient.withSimulatedLatency(latency);
+        delegate = MemoizedFirebase.withSimulatedLatency(latency);
         path = NodePaths.of("some/kind/of/path");
         executor = newSingleThreadExecutor();
     }
@@ -78,14 +78,14 @@ void executeWritesWithForkJoinPool() {
     void allowDirectExecutor() {
         AsyncClient asyncClient = new AsyncClient(delegate, directExecutor());
         asyncClient.create(path, NodeValue.empty());
-        assertThat(delegate.writes()).contains(path);
+        assertThat(delegate.writes()).containsKey(path);
     }
 
     private void checkAsync(AsyncClient asyncClient) {
         asyncClient.update(path, NodeValue.empty());
-        assertThat(delegate.writes()).doesNotContain(path);
+        assertThat(delegate.writes()).doesNotContainKey(path);
         Duration surefireTime = latency.plusSeconds(1);
         Uninterruptibles.sleepUninterruptibly(surefireTime);
-        assertThat(delegate.writes()).contains(path);
+        assertThat(delegate.writes()).containsKey(path);
     }
 }
diff --git a/firebase-web/src/test/java/io/spine/web/firebase/given/TestFirebaseClient.java b/firebase-web/src/test/java/io/spine/web/firebase/given/MemoizedFirebase.java
similarity index 71%
rename from firebase-web/src/test/java/io/spine/web/firebase/given/TestFirebaseClient.java
rename to firebase-web/src/test/java/io/spine/web/firebase/given/MemoizedFirebase.java
index 0086b0d9a..e03e7a6ff 100644
--- a/firebase-web/src/test/java/io/spine/web/firebase/given/TestFirebaseClient.java
+++ b/firebase-web/src/test/java/io/spine/web/firebase/given/MemoizedFirebase.java
@@ -21,39 +21,52 @@
 package io.spine.web.firebase.given;
 
 import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableMap;
 import com.google.firebase.database.ChildEventListener;
 import io.spine.web.firebase.FirebaseClient;
 import io.spine.web.firebase.NodePath;
 import io.spine.web.firebase.NodeValue;
 
 import java.time.Duration;
+import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
 import java.util.Optional;
 
 import static com.google.common.base.Preconditions.checkNotNull;
 import static com.google.common.collect.Lists.newArrayList;
 import static com.google.common.util.concurrent.Uninterruptibles.sleepUninterruptibly;
 
-public final class TestFirebaseClient implements FirebaseClient {
+/**
+ * A Firebase client that memoizes read and write operations.
+ *
+ * <p>Supports having a custom write latency through {@linkplain #withSimulatedLatency(Duration)
+ * setting} a particular write operations duration.
+ */
+public final class MemoizedFirebase implements FirebaseClient {
 
+    private final Map<NodePath, NodeValue> writes = new HashMap<>();
     private final List<NodePath> reads = newArrayList();
-    private final List<NodePath> writes = newArrayList();
 
     private final Duration writeLatency;
 
-    private TestFirebaseClient(Duration latency) {
+    private MemoizedFirebase(Duration latency) {
         this.writeLatency = latency;
     }
 
-    public static TestFirebaseClient withSimulatedLatency(Duration latency) {
+    public static MemoizedFirebase withNoLatency() {
+        return withSimulatedLatency(Duration.ZERO);
+    }
+
+    public static MemoizedFirebase withSimulatedLatency(Duration latency) {
         checkNotNull(latency);
-        return new TestFirebaseClient(latency);
+        return new MemoizedFirebase(latency);
     }
 
     @Override
     public Optional<NodeValue> fetchNode(NodePath nodePath) {
         reads.add(nodePath);
-        return Optional.empty();
+        return Optional.ofNullable(writes.get(nodePath));
     }
 
     @Override
@@ -64,26 +77,26 @@ public void subscribeTo(NodePath nodePath, ChildEventListener listener) {
     @Override
     public void create(NodePath nodePath, NodeValue value) {
         sleepUninterruptibly(writeLatency);
-        writes.add(nodePath);
+        writes.put(nodePath, value);
     }
 
     @Override
     public void update(NodePath nodePath, NodeValue value) {
         sleepUninterruptibly(writeLatency);
-        writes.add(nodePath);
+        writes.put(nodePath, value);
     }
 
     @Override
     public void delete(NodePath nodePath) {
         sleepUninterruptibly(writeLatency);
-        writes.add(nodePath);
+        writes.remove(nodePath);
     }
 
     public ImmutableList<NodePath> reads() {
         return ImmutableList.copyOf(reads);
     }
 
-    public ImmutableList<NodePath> writes() {
-        return ImmutableList.copyOf(writes);
+    public ImmutableMap<NodePath, NodeValue> writes() {
+        return ImmutableMap.copyOf(writes);
     }
 }

From bffdbc1205aca72911e37f9e25decd8c91738709 Mon Sep 17 00:00:00 2001
From: Yuri Sergiichuk <yuri.sergiichuk@teamdev.com>
Date: Mon, 7 Dec 2020 11:24:58 +0200
Subject: [PATCH 15/41] Drop Mockito usage.

---
 .../io/spine/web/firebase/StoredJson.java     |  7 +-
 .../web/firebase/given/MemoizedFirebase.java  | 23 ++++++
 .../query/FirebaseQueryBridgeTest.java        | 79 +++++++++++++------
 3 files changed, 83 insertions(+), 26 deletions(-)

diff --git a/firebase-web/src/main/java/io/spine/web/firebase/StoredJson.java b/firebase-web/src/main/java/io/spine/web/firebase/StoredJson.java
index 2b5c14647..d3c233191 100644
--- a/firebase-web/src/main/java/io/spine/web/firebase/StoredJson.java
+++ b/firebase-web/src/main/java/io/spine/web/firebase/StoredJson.java
@@ -26,6 +26,7 @@
 import com.google.gson.JsonParser;
 import com.google.protobuf.Any;
 import com.google.protobuf.Message;
+import io.spine.annotation.Internal;
 import io.spine.protobuf.AnyPacker;
 import io.spine.value.StringTypeValue;
 
@@ -84,7 +85,11 @@ public NodeValue asNodeValue() {
         return NodeValue.from(this);
     }
 
-    JsonObject asJsonObject() {
+    /**
+     * Parses the JSON string into a {@code JsonObject}.
+     */
+    @Internal
+    public JsonObject asJsonObject() {
         JsonParser parser = new JsonParser();
         JsonElement object = parser.parse(value());
         return object.getAsJsonObject();
diff --git a/firebase-web/src/test/java/io/spine/web/firebase/given/MemoizedFirebase.java b/firebase-web/src/test/java/io/spine/web/firebase/given/MemoizedFirebase.java
index e03e7a6ff..8046a9553 100644
--- a/firebase-web/src/test/java/io/spine/web/firebase/given/MemoizedFirebase.java
+++ b/firebase-web/src/test/java/io/spine/web/firebase/given/MemoizedFirebase.java
@@ -36,6 +36,7 @@
 import static com.google.common.base.Preconditions.checkNotNull;
 import static com.google.common.collect.Lists.newArrayList;
 import static com.google.common.util.concurrent.Uninterruptibles.sleepUninterruptibly;
+import static io.spine.util.Exceptions.newIllegalStateException;
 
 /**
  * A Firebase client that memoizes read and write operations.
@@ -92,11 +93,33 @@ public void delete(NodePath nodePath) {
         writes.remove(nodePath);
     }
 
+    /**
+     * Returns a copy of all made read operations.
+     */
     public ImmutableList<NodePath> reads() {
         return ImmutableList.copyOf(reads);
     }
 
+    /**
+     * Returns a copy of all made write operation.
+     */
     public ImmutableMap<NodePath, NodeValue> writes() {
         return ImmutableMap.copyOf(writes);
     }
+
+    /**
+     * Returns a {@code NodeValue} written to a specific {@code path}.
+     *
+     * @throws IllegalStateException
+     *         if no value is present for the path.
+     */
+    public NodeValue valueFor(NodePath path) {
+        NodeValue result = writes.get(path);
+        if (result == null) {
+            throw newIllegalStateException(
+                    "A value is expected to be present at path `%s`.", path.getValue()
+            );
+        }
+        return result;
+    }
 }
diff --git a/firebase-web/src/test/java/io/spine/web/firebase/query/FirebaseQueryBridgeTest.java b/firebase-web/src/test/java/io/spine/web/firebase/query/FirebaseQueryBridgeTest.java
index 18e63eccf..ec8e51615 100644
--- a/firebase-web/src/test/java/io/spine/web/firebase/query/FirebaseQueryBridgeTest.java
+++ b/firebase-web/src/test/java/io/spine/web/firebase/query/FirebaseQueryBridgeTest.java
@@ -20,34 +20,37 @@
 
 package io.spine.web.firebase.query;
 
+import com.google.common.collect.Iterators;
+import com.google.common.truth.Truth;
+import com.google.gson.JsonElement;
+import com.google.gson.JsonObject;
+import com.google.protobuf.Message;
 import io.spine.client.Query;
 import io.spine.client.QueryFactory;
 import io.spine.core.Event;
+import io.spine.json.Json;
 import io.spine.server.BoundedContextBuilder;
 import io.spine.server.QueryService;
 import io.spine.testing.client.TestActorRequestFactory;
 import io.spine.web.firebase.FirebaseClient;
+import io.spine.web.firebase.NodePaths;
+import io.spine.web.firebase.NodeValue;
+import io.spine.web.firebase.StoredJson;
 import io.spine.web.firebase.given.Book;
 import io.spine.web.firebase.given.BookId;
-import io.spine.web.given.TestQueryService;
-import io.spine.web.firebase.subscription.given.HasChildren;
+import io.spine.web.firebase.given.MemoizedFirebase;
 import io.spine.web.given.TestQueryService;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.DisplayName;
 import org.junit.jupiter.api.Test;
 
-import java.util.HashMap;
 import java.util.Map;
+import java.util.Set;
 
+import static com.google.common.truth.extensions.proto.ProtoTruth.assertThat;
 import static io.spine.base.Identifier.newUuid;
-import static com.google.common.truth.Truth.assertThat;
-import static io.spine.json.Json.toCompactJson;
-import static io.spine.web.firebase.subscription.given.HasChildren.anyKey;
 import static org.junit.jupiter.api.Assertions.assertThrows;
-import static org.mockito.ArgumentMatchers.any;
-import static org.mockito.ArgumentMatchers.argThat;
 import static org.mockito.Mockito.mock;
-import static org.mockito.Mockito.verify;
 
 @DisplayName("FirebaseQueryBridge should")
 class FirebaseQueryBridgeTest {
@@ -55,11 +58,11 @@ class FirebaseQueryBridgeTest {
     private static final QueryFactory queryFactory =
             new TestActorRequestFactory(FirebaseQueryBridgeTest.class).query();
 
-    private FirebaseClient firebaseClient;
+    private MemoizedFirebase firebaseClient;
 
     @BeforeEach
     void setUp() {
-        firebaseClient = mock(FirebaseClient.class);
+        firebaseClient = MemoizedFirebase.withNoLatency();
     }
 
     @SuppressWarnings({"ResultOfMethodCallIgnored", "CheckReturnValue"}) // Method called to throw.
@@ -78,7 +81,8 @@ void requireQueryService() {
     void requireFirebaseClient() {
         QueryService queryService = QueryService
                 .newBuilder()
-                .add(BoundedContextBuilder.assumingTests().build())
+                .add(BoundedContextBuilder.assumingTests()
+                                          .build())
                 .build();
         FirebaseQueryBridge.Builder builder = FirebaseQueryBridge
                 .newBuilder()
@@ -90,13 +94,15 @@ void requireFirebaseClient() {
     @DisplayName("produce a database path for the given query results")
     void testMediate() {
         TestQueryService queryService = new TestQueryService();
-        FirebaseQueryBridge bridge = FirebaseQueryBridge.newBuilder()
-                                                        .setQueryService(queryService)
-                                                        .setFirebaseClient(firebaseClient)
-                                                        .build();
+        FirebaseQueryBridge bridge = FirebaseQueryBridge
+                .newBuilder()
+                .setQueryService(queryService)
+                .setFirebaseClient(firebaseClient)
+                .build();
         Query query = queryFactory.all(Event.class);
         FirebaseQueryResponse response = bridge.send(query);
-        assertThat(response).isNotNull();
+        Truth.assertThat(response)
+             .isNotNull();
     }
 
     @Test
@@ -112,15 +118,38 @@ void testWriteData() {
                 .setName(newUuid())
                 .build();
         TestQueryService queryService = new TestQueryService(book);
-        FirebaseQueryBridge bridge = FirebaseQueryBridge.newBuilder()
-                                                        .setQueryService(queryService)
-                                                        .setFirebaseClient(firebaseClient)
-                                                        .build();
+        FirebaseQueryBridge bridge = FirebaseQueryBridge
+                .newBuilder()
+                .setQueryService(queryService)
+                .setFirebaseClient(firebaseClient)
+                .build();
         Query query = queryFactory.all(Book.class);
-        bridge.send(query);
+        FirebaseQueryResponse response = bridge.send(query);
+        NodeValue nodeValue = firebaseClient.valueFor(NodePaths.of(response.getPath()));
+        Book actual = firstFieldOf(nodeValue, Book.class);
+        assertThat(actual).isEqualTo(book);
+    }
 
-        Map<String, String> expected = new HashMap<>();
-        expected.put(anyKey(), toCompactJson(book));
-        verify(firebaseClient).create(any(), argThat(new HasChildren(expected)));
+    /**
+     * Returns the {@code message} stored in the first JSON element of the {@code nodeValue}.
+     *
+     * <p>The node has a single randomized field with the field value being a serialized
+     * processed message.
+     *
+     * @implNote the {@code nodeValue} holds data as a JSON primitive string (i.e. an
+     *         escaped string that actually holds a JSON object), thus we're forced to parse
+     *         the string into a JSON object first and then convert it back to a string.
+     */
+    private static <T extends Message> T firstFieldOf(NodeValue nodeValue, Class<T> message) {
+        JsonObject json = nodeValue.underlyingJson();
+        Set<Map.Entry<String, JsonElement>> entries = json.entrySet();
+        JsonElement value = Iterators
+                .getOnlyElement(entries.iterator())
+                .getValue();
+        String messageJson = StoredJson
+                .from(value.getAsString())
+                .asJsonObject()
+                .toString();
+        return Json.fromJson(messageJson, message);
     }
 }

From a55f78277c26ebbbad027232f72fbe631b8f244a Mon Sep 17 00:00:00 2001
From: Yuri Sergiichuk <yuri.sergiichuk@teamdev.com>
Date: Mon, 7 Dec 2020 11:39:35 +0200
Subject: [PATCH 16/41] Eliminate Mockito usage.

---
 .../firebase/given/FirebaseResultTestEnv.java |  55 ----------
 .../FirebaseSubscriptionBridgeTestEnv.java    |  12 --
 .../query/FirebaseQueryBridgeTest.java        |   4 +-
 .../FirebaseSubscriptionBridgeTest.java       |  10 +-
 .../subscription/given/HasChildren.java       | 103 ------------------
 5 files changed, 6 insertions(+), 178 deletions(-)
 delete mode 100644 firebase-web/src/test/java/io/spine/web/firebase/given/FirebaseResultTestEnv.java
 delete mode 100644 firebase-web/src/test/java/io/spine/web/firebase/subscription/given/HasChildren.java

diff --git a/firebase-web/src/test/java/io/spine/web/firebase/given/FirebaseResultTestEnv.java b/firebase-web/src/test/java/io/spine/web/firebase/given/FirebaseResultTestEnv.java
deleted file mode 100644
index a88f3cc6c..000000000
--- a/firebase-web/src/test/java/io/spine/web/firebase/given/FirebaseResultTestEnv.java
+++ /dev/null
@@ -1,55 +0,0 @@
-/*
- * Copyright 2020, TeamDev. All rights reserved.
- *
- * Redistribution and use in source and/or binary forms, with or without
- * modification, must retain the above copyright notice and the following
- * disclaimer.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
-package io.spine.web.firebase.given;
-
-import io.spine.core.Response;
-
-import javax.servlet.ServletResponse;
-import java.io.IOException;
-import java.io.PrintWriter;
-import java.io.StringWriter;
-
-import static io.spine.core.Responses.statusOk;
-import static org.mockito.Mockito.when;
-
-public final class FirebaseResultTestEnv {
-
-    /**
-     * Prevents instantiation of this test environment.
-     */
-    private FirebaseResultTestEnv() {
-    }
-
-    public static StringWriter mockWriter(ServletResponse response) throws IOException {
-        StringWriter stringWriter = new StringWriter();
-        PrintWriter writer = new PrintWriter(stringWriter);
-        when(response.getWriter()).thenReturn(writer);
-        return stringWriter;
-    }
-
-    public static Response okCancelSubscriptionResult() {
-        Response response = Response
-                .newBuilder()
-                .setStatus(statusOk())
-                .vBuild();
-        return response;
-    }
-}
diff --git a/firebase-web/src/test/java/io/spine/web/firebase/given/FirebaseSubscriptionBridgeTestEnv.java b/firebase-web/src/test/java/io/spine/web/firebase/given/FirebaseSubscriptionBridgeTestEnv.java
index 39705ac40..1ac620e94 100644
--- a/firebase-web/src/test/java/io/spine/web/firebase/given/FirebaseSubscriptionBridgeTestEnv.java
+++ b/firebase-web/src/test/java/io/spine/web/firebase/given/FirebaseSubscriptionBridgeTestEnv.java
@@ -36,17 +36,12 @@
 import io.spine.web.firebase.NodePath;
 import io.spine.web.firebase.subscription.FirebaseSubscriptionBridge;
 
-import javax.servlet.ServletResponse;
-import java.io.IOException;
-import java.io.PrintWriter;
-import java.io.StringWriter;
 import java.util.Collection;
 import java.util.regex.Pattern;
 
 import static com.google.common.collect.Lists.newArrayList;
 import static com.google.common.truth.Truth.assertThat;
 import static io.spine.core.Responses.statusOk;
-import static org.mockito.Mockito.when;
 
 @SuppressWarnings("DuplicateStringLiteralInspection") // Duplicate strings for testing.
 public final class FirebaseSubscriptionBridgeTestEnv {
@@ -90,13 +85,6 @@ public static Response newResponse() {
                 .vBuild();
     }
 
-    public static StringWriter mockWriter(ServletResponse response) throws IOException {
-        StringWriter stringWriter = new StringWriter();
-        PrintWriter writer = new PrintWriter(stringWriter);
-        when(response.getWriter()).thenReturn(writer);
-        return stringWriter;
-    }
-
     public static Subscription newSubscription(Topic topic) {
         return Subscription
                 .newBuilder()
diff --git a/firebase-web/src/test/java/io/spine/web/firebase/query/FirebaseQueryBridgeTest.java b/firebase-web/src/test/java/io/spine/web/firebase/query/FirebaseQueryBridgeTest.java
index ec8e51615..3680090de 100644
--- a/firebase-web/src/test/java/io/spine/web/firebase/query/FirebaseQueryBridgeTest.java
+++ b/firebase-web/src/test/java/io/spine/web/firebase/query/FirebaseQueryBridgeTest.java
@@ -32,7 +32,6 @@
 import io.spine.server.BoundedContextBuilder;
 import io.spine.server.QueryService;
 import io.spine.testing.client.TestActorRequestFactory;
-import io.spine.web.firebase.FirebaseClient;
 import io.spine.web.firebase.NodePaths;
 import io.spine.web.firebase.NodeValue;
 import io.spine.web.firebase.StoredJson;
@@ -50,7 +49,6 @@
 import static com.google.common.truth.extensions.proto.ProtoTruth.assertThat;
 import static io.spine.base.Identifier.newUuid;
 import static org.junit.jupiter.api.Assertions.assertThrows;
-import static org.mockito.Mockito.mock;
 
 @DisplayName("FirebaseQueryBridge should")
 class FirebaseQueryBridgeTest {
@@ -71,7 +69,7 @@ void setUp() {
     void requireQueryService() {
         FirebaseQueryBridge.Builder builder = FirebaseQueryBridge
                 .newBuilder()
-                .setFirebaseClient(mock(FirebaseClient.class));
+                .setFirebaseClient(firebaseClient);
         assertThrows(IllegalStateException.class, builder::build);
     }
 
diff --git a/firebase-web/src/test/java/io/spine/web/firebase/subscription/FirebaseSubscriptionBridgeTest.java b/firebase-web/src/test/java/io/spine/web/firebase/subscription/FirebaseSubscriptionBridgeTest.java
index 7ea2af628..e2a1975ae 100644
--- a/firebase-web/src/test/java/io/spine/web/firebase/subscription/FirebaseSubscriptionBridgeTest.java
+++ b/firebase-web/src/test/java/io/spine/web/firebase/subscription/FirebaseSubscriptionBridgeTest.java
@@ -28,6 +28,7 @@
 import io.spine.server.BoundedContextBuilder;
 import io.spine.server.SubscriptionService;
 import io.spine.web.firebase.FirebaseClient;
+import io.spine.web.firebase.given.MemoizedFirebase;
 import io.spine.web.firebase.subscription.given.InMemFirebaseClient;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.DisplayName;
@@ -43,9 +44,8 @@
 import static io.spine.web.firebase.given.FirebaseSubscriptionBridgeTestEnv.newTarget;
 import static io.spine.web.firebase.given.FirebaseSubscriptionBridgeTestEnv.topicFactory;
 import static org.junit.jupiter.api.Assertions.assertThrows;
-import static org.mockito.Mockito.mock;
 
-@DisplayName("FirebaseSubscriptionBridge should")
+@DisplayName("`FirebaseSubscriptionBridge` should")
 class FirebaseSubscriptionBridgeTest {
 
     private FirebaseSubscriptionBridge bridge;
@@ -59,19 +59,19 @@ void setUp() {
         topicFactory = topicFactory();
     }
 
-    @SuppressWarnings({"ResultOfMethodCallIgnored", "CheckReturnValue"}) // Method called to throw.
     @Test
     @DisplayName("require Query Service set in Builder")
+    @SuppressWarnings({"ResultOfMethodCallIgnored", "CheckReturnValue"}) // Method called to throw.
     void requireQueryService() {
         FirebaseSubscriptionBridge.Builder builder = FirebaseSubscriptionBridge
                 .newBuilder()
-                .setFirebaseClient(mock(FirebaseClient.class));
+                .setFirebaseClient(MemoizedFirebase.withNoLatency());
         assertThrows(IllegalStateException.class, builder::build);
     }
 
-    @SuppressWarnings({"ResultOfMethodCallIgnored", "CheckReturnValue"}) // Method called to throw.
     @Test
     @DisplayName("require Firebase Client set in Builder")
+    @SuppressWarnings({"ResultOfMethodCallIgnored", "CheckReturnValue"}) // Method called to throw.
     void requireFirebaseClient() {
         SubscriptionService subscriptionService = SubscriptionService
                 .newBuilder()
diff --git a/firebase-web/src/test/java/io/spine/web/firebase/subscription/given/HasChildren.java b/firebase-web/src/test/java/io/spine/web/firebase/subscription/given/HasChildren.java
deleted file mode 100644
index 8f7b42123..000000000
--- a/firebase-web/src/test/java/io/spine/web/firebase/subscription/given/HasChildren.java
+++ /dev/null
@@ -1,103 +0,0 @@
-/*
- * Copyright 2020, TeamDev. All rights reserved.
- *
- * Redistribution and use in source and/or binary forms, with or without
- * modification, must retain the above copyright notice and the following
- * disclaimer.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
-package io.spine.web.firebase.subscription.given;
-
-import com.google.common.collect.ImmutableMap;
-import com.google.gson.JsonElement;
-import com.google.gson.JsonObject;
-import io.spine.web.firebase.NodeValue;
-import org.mockito.ArgumentMatcher;
-
-import java.util.List;
-import java.util.Map;
-import java.util.UUID;
-
-import static com.google.common.base.Preconditions.checkNotNull;
-import static java.util.stream.Collectors.toList;
-
-/**
- * A checker of {@code NodeValue} instances used in Firebase requests.
- *
- * <p>By default checks that the value contains all the {@linkplain #expected expected} entries
- * under the specified keys.
- *
- * <p>If {@link #ANY_KEY} is specified as entry key then the checker verifies that corresponding
- * value is present under any of the keys in the tested object.
- */
-public class HasChildren implements ArgumentMatcher<NodeValue> {
-
-    private static final String ANY_KEY = "any_key";
-    public static final String JSON_NULL = "json_null";
-
-    private final ImmutableMap<String, String> expected;
-
-    /**
-     * Creates a new matcher for the specified expected entries.
-     *
-     * @param expected
-     *         the expected entries in "nodeKey-nodeValue" format
-     */
-    public HasChildren(Map<String, String> expected) {
-        this.expected = ImmutableMap.copyOf(expected);
-    }
-
-    @Override
-    public boolean matches(NodeValue nodeValue) {
-        JsonObject actual = nodeValue.underlyingJson();
-        for (Map.Entry<String, String> entry : expected.entrySet()) {
-            String key = entry.getKey();
-            String value = entry.getValue();
-            if (!hasKeyAndValue(actual, key, value)) {
-                return false;
-            }
-        }
-        return true;
-    }
-
-    private static boolean hasKeyAndValue(JsonObject json, String key, String value) {
-        checkNotNull(json);
-        checkNotNull(key);
-        if (key.startsWith(ANY_KEY)) {
-            List<Map.Entry<String, JsonElement>> containingValue = json
-                    .entrySet()
-                    .stream()
-                    .filter(e -> equalsOrNull(e.getValue(), value))
-                    .collect(toList());
-            boolean result = !containingValue.isEmpty();
-            return result;
-        } else {
-            boolean result = json.has(key) && equalsOrNull(json.get(key), value);
-            return result;
-        }
-    }
-
-    public static String anyKey() {
-        return ANY_KEY + UUID.randomUUID().toString();
-    }
-
-    private static boolean equalsOrNull(JsonElement element, String value) {
-        if (element.isJsonNull()) {
-            return value.equals(JSON_NULL);
-        }
-
-        return element.getAsString().equals(value);
-    }
-}

From d2fb8ec626385551f1ae872ab34fef24ac6510cd Mon Sep 17 00:00:00 2001
From: Yuri Sergiichuk <yuri.sergiichuk@teamdev.com>
Date: Mon, 7 Dec 2020 12:12:33 +0200
Subject: [PATCH 17/41] The final Mockito-less step.

---
 build.gradle.kts                              |   1 -
 .../firebase/rest/HttpClientMockFactory.java  | 131 ++++++++++++++++++
 .../web/firebase/rest/HttpClientTest.java     |  77 ++--------
 .../rest/RemoteDatabaseClientTest.java        |  41 +++---
 4 files changed, 164 insertions(+), 86 deletions(-)
 create mode 100644 firebase-web/src/test/java/io/spine/web/firebase/rest/HttpClientMockFactory.java

diff --git a/build.gradle.kts b/build.gradle.kts
index 65db30911..2f246c43d 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -122,7 +122,6 @@ subprojects {
 
         testImplementation("io.spine:spine-testutil-client:$spineCoreVersion")
         testImplementation(Deps.test.guavaTestlib)
-        testImplementation(Deps.test.mockito)
         Deps.test.junit5Api.forEach { testImplementation(it) }
         Deps.test.truth.forEach { testImplementation(it) }
         testRuntimeOnly(Deps.test.junit5Runner)
diff --git a/firebase-web/src/test/java/io/spine/web/firebase/rest/HttpClientMockFactory.java b/firebase-web/src/test/java/io/spine/web/firebase/rest/HttpClientMockFactory.java
new file mode 100644
index 000000000..2230db052
--- /dev/null
+++ b/firebase-web/src/test/java/io/spine/web/firebase/rest/HttpClientMockFactory.java
@@ -0,0 +1,131 @@
+/*
+ * Copyright 2020, TeamDev. All rights reserved.
+ *
+ * Redistribution and use in source and/or binary forms, with or without
+ * modification, must retain the above copyright notice and the following
+ * disclaimer.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+package io.spine.web.firebase.rest;
+
+import com.google.api.client.http.HttpRequestFactory;
+import com.google.api.client.http.HttpTransport;
+import com.google.api.client.http.LowLevelHttpRequest;
+import com.google.api.client.testing.http.MockHttpTransport;
+import com.google.api.client.testing.http.MockLowLevelHttpRequest;
+import com.google.api.client.testing.http.MockLowLevelHttpResponse;
+
+import java.io.IOException;
+
+/**
+ * Creates mocked {@link HttpClient}s.
+ */
+final class HttpClientMockFactory {
+
+    /**
+     * Prevents instantiation of this utility class.
+     */
+    private HttpClientMockFactory() {
+    }
+
+    /**
+     * Creates a new no-operation {@code HttpClient}.
+     */
+    static HttpClient noOpClient() {
+        MockHttpTransport transport = new MockHttpTransport.Builder().build();
+        return HttpClient.using(transport.createRequestFactory());
+    }
+
+    /**
+     * Creates an {@code HttpClient} mock which returns the specified {@code content}
+     * on every request.
+     */
+    static HttpClient mockHttpClient(String content) {
+        return mockHttpClient(content, HttpClientMockFactory::noOpObserver);
+    }
+
+    /**
+     * Creates an {@code HttpClient} mock which returns the specified {@code content}
+     * on every request and uses supplied {@code observer} while building requests.
+     */
+    static HttpClient mockHttpClient(String content, RequestObserver observer) {
+        return HttpClient.using(mockRequestFactory(content, observer));
+    }
+
+    private static HttpRequestFactory
+    mockRequestFactory(String content, RequestObserver observer) {
+        HttpTransport transportMock = mockHttpTransport(content, observer);
+        HttpRequestFactory requestFactoryMock = transportMock.createRequestFactory();
+        return requestFactoryMock;
+    }
+
+    private static HttpTransport
+    mockHttpTransport(String content, RequestObserver observer) {
+        final MockLowLevelHttpResponse response = new MockLowLevelHttpResponse();
+        response.setContent(content);
+        return new MockHttpTransport() {
+            @Override
+            public LowLevelHttpRequest
+            buildRequest(String method, String url) {
+                MockLowLevelHttpRequest request = new MockLowLevelHttpRequest(url);
+                request.setResponse(response);
+                observer.onRequest(method, url);
+                return request;
+            }
+        };
+    }
+
+    /**
+     * Creates an {@code HttpClient} mock which throws {@link java.io.IOException} on every
+     * request.
+     */
+    static HttpClient throwingClient() {
+        return HttpClient.using(throwingRequestFactory());
+    }
+
+    private static HttpRequestFactory throwingRequestFactory() {
+        HttpRequestFactory result = throwingHttpTransport().createRequestFactory();
+        return result;
+    }
+
+    private static MockHttpTransport throwingHttpTransport() {
+        return new MockHttpTransport() {
+            @Override
+            public LowLevelHttpRequest
+            buildRequest(String method, String url) throws IOException {
+                throw new IOException("Intended exception");
+            }
+        };
+    }
+
+    private static void noOpObserver(String method, String url) {
+    }
+
+    /**
+     * Observes built HTTP requests.
+     */
+    interface RequestObserver {
+
+        /**
+         * A callback that is executed whenever an HTTP request is built.
+         *
+         * @param method
+         *         the HTTP method being used
+         * @param url
+         *         the request URL
+         */
+        void onRequest(String method, String url);
+    }
+}
diff --git a/firebase-web/src/test/java/io/spine/web/firebase/rest/HttpClientTest.java b/firebase-web/src/test/java/io/spine/web/firebase/rest/HttpClientTest.java
index 1c5b56ad9..efe9ac117 100644
--- a/firebase-web/src/test/java/io/spine/web/firebase/rest/HttpClientTest.java
+++ b/firebase-web/src/test/java/io/spine/web/firebase/rest/HttpClientTest.java
@@ -22,25 +22,18 @@
 
 import com.google.api.client.http.ByteArrayContent;
 import com.google.api.client.http.GenericUrl;
-import com.google.api.client.http.HttpRequestFactory;
-import com.google.api.client.http.HttpTransport;
-import com.google.api.client.http.LowLevelHttpRequest;
-import com.google.api.client.http.LowLevelHttpResponse;
-import com.google.api.client.testing.http.MockHttpTransport;
-import com.google.api.client.testing.http.MockLowLevelHttpRequest;
-import com.google.api.client.testing.http.MockLowLevelHttpResponse;
 import org.junit.jupiter.api.DisplayName;
 import org.junit.jupiter.api.Test;
 
-import java.io.IOException;
-
 import static com.google.api.client.http.ByteArrayContent.fromString;
 import static com.google.common.net.MediaType.JSON_UTF_8;
+import static io.spine.web.firebase.rest.HttpClientMockFactory.mockHttpClient;
+import static io.spine.web.firebase.rest.HttpClientMockFactory.throwingClient;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertThrows;
 
+@DisplayName("`HttpClient` should")
 @SuppressWarnings({"ResultOfMethodCallIgnored", "CheckReturnValue"}) // Calling methods to throw.
-@DisplayName("HttpClient should")
 class HttpClientTest {
 
     private static final GenericUrl URL = new GenericUrl("https://localhost:8080");
@@ -50,8 +43,7 @@ class HttpClientTest {
     @Test
     @DisplayName("execute GET request")
     void executeGetRequest() {
-        HttpRequestFactory transport = mockRequestFactory(RESPONSE);
-        HttpClient requestExecutor = HttpClient.using(transport);
+        HttpClient requestExecutor = mockHttpClient(RESPONSE);
         String content = requestExecutor.get(URL);
         assertEquals(RESPONSE, content);
     }
@@ -59,16 +51,14 @@ void executeGetRequest() {
     @Test
     @DisplayName("throw RequestToFirebaseFailedException if an error occurs on GET request")
     void throwIfErrorOnGet() {
-        HttpRequestFactory transport = throwingRequestFactory();
-        HttpClient requestExecutor = HttpClient.using(transport);
+        HttpClient requestExecutor = throwingClient();
         assertThrows(RequestToFirebaseFailedException.class, () -> requestExecutor.get(URL));
     }
 
     @Test
     @DisplayName("execute PUT request")
     void executePutRequest() {
-        HttpRequestFactory transport = mockRequestFactory(RESPONSE);
-        HttpClient requestExecutor = HttpClient.using(transport);
+        HttpClient requestExecutor = mockHttpClient(RESPONSE);
         String content = requestExecutor.put(URL, CONTENT);
         assertEquals(RESPONSE, content);
     }
@@ -76,8 +66,7 @@ void executePutRequest() {
     @Test
     @DisplayName("throw RequestToFirebaseFailedException if an error occurs on PUT request")
     void throwIfErrorOnPut() {
-        HttpRequestFactory transport = throwingRequestFactory();
-        HttpClient requestExecutor = HttpClient.using(transport);
+        HttpClient requestExecutor = throwingClient();
         assertThrows(RequestToFirebaseFailedException.class,
                      () -> requestExecutor.put(URL, CONTENT));
     }
@@ -85,8 +74,7 @@ void throwIfErrorOnPut() {
     @Test
     @DisplayName("execute PATCH request")
     void executePatchRequest() {
-        HttpRequestFactory transport = mockRequestFactory(RESPONSE);
-        HttpClient requestExecutor = HttpClient.using(transport);
+        HttpClient requestExecutor = mockHttpClient(RESPONSE);
         String content = requestExecutor.patch(URL, CONTENT);
         assertEquals(RESPONSE, content);
     }
@@ -94,55 +82,8 @@ void executePatchRequest() {
     @Test
     @DisplayName("throw RequestToFirebaseFailedException if an error occurs on PATCH request")
     void throwIfErrorOnPatch() {
-        HttpRequestFactory transport = throwingRequestFactory();
-        HttpClient requestExecutor = HttpClient.using(transport);
+        HttpClient requestExecutor = throwingClient();
         assertThrows(RequestToFirebaseFailedException.class,
                      () -> requestExecutor.patch(URL, CONTENT));
     }
-
-    /**
-     * Returns an {@code HttpRequestFactory} mock which returns the specified content on every
-     * request.
-     */
-    private static HttpRequestFactory mockRequestFactory(String content) {
-        HttpTransport transportMock = mockHttpTransport(content);
-        HttpRequestFactory requestFactoryMock = transportMock.createRequestFactory();
-        return requestFactoryMock;
-    }
-
-    /**
-     * Returns an {@code HttpRequestFactory} mock which throws {@link java.io.IOException} on every
-     * request.
-     */
-    private static HttpRequestFactory throwingRequestFactory() {
-        HttpRequestFactory result = throwingHttpTransport().createRequestFactory();
-        return result;
-    }
-
-    private static HttpTransport mockHttpTransport(String content) {
-        return new MockHttpTransport() {
-            @Override
-            public LowLevelHttpRequest
-            buildRequest(String method, String url) {
-                return new MockLowLevelHttpRequest() {
-                    @Override
-                    public LowLevelHttpResponse execute() {
-                        MockLowLevelHttpResponse response = new MockLowLevelHttpResponse();
-                        response.setContent(content);
-                        return response;
-                    }
-                };
-            }
-        };
-    }
-
-    private static MockHttpTransport throwingHttpTransport() {
-        return new MockHttpTransport() {
-            @Override
-            public LowLevelHttpRequest
-            buildRequest(String method, String url) throws IOException {
-                throw new IOException("Intended exception");
-            }
-        };
-    }
 }
diff --git a/firebase-web/src/test/java/io/spine/web/firebase/rest/RemoteDatabaseClientTest.java b/firebase-web/src/test/java/io/spine/web/firebase/rest/RemoteDatabaseClientTest.java
index 0b56f2b2e..f50d53415 100644
--- a/firebase-web/src/test/java/io/spine/web/firebase/rest/RemoteDatabaseClientTest.java
+++ b/firebase-web/src/test/java/io/spine/web/firebase/rest/RemoteDatabaseClientTest.java
@@ -20,8 +20,8 @@
 
 package io.spine.web.firebase.rest;
 
-import com.google.api.client.http.ByteArrayContent;
 import com.google.api.client.http.GenericUrl;
+import com.google.api.client.http.HttpMethods;
 import com.google.api.client.http.HttpRequestFactory;
 import com.google.api.client.testing.http.MockHttpTransport;
 import com.google.auth.oauth2.AccessToken;
@@ -32,6 +32,7 @@
 import com.google.firebase.database.FirebaseDatabase;
 import io.spine.web.firebase.DatabaseUrl;
 import io.spine.web.firebase.DatabaseUrls;
+import io.spine.web.firebase.FirebaseClient;
 import io.spine.web.firebase.NodePath;
 import io.spine.web.firebase.NodePaths;
 import io.spine.web.firebase.NodeValue;
@@ -45,17 +46,15 @@
 import java.util.Date;
 import java.util.Optional;
 
+import static com.google.common.truth.Truth.assertThat;
 import static io.spine.testing.DisplayNames.NOT_ACCEPT_NULLS;
+import static io.spine.web.firebase.rest.HttpClientMockFactory.mockHttpClient;
+import static io.spine.web.firebase.rest.HttpClientMockFactory.noOpClient;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertFalse;
 import static org.junit.jupiter.api.Assertions.assertNotNull;
 import static org.junit.jupiter.api.Assertions.assertThrows;
 import static org.junit.jupiter.api.Assertions.assertTrue;
-import static org.mockito.ArgumentMatchers.any;
-import static org.mockito.ArgumentMatchers.eq;
-import static org.mockito.Mockito.mock;
-import static org.mockito.Mockito.verify;
-import static org.mockito.Mockito.when;
 
 @DisplayName("`RemoteDatabaseClient` should")
 class RemoteDatabaseClientTest {
@@ -71,8 +70,7 @@ class RemoteDatabaseClientTest {
     private static final GenericUrl EXPECTED_NODE_URL =
             new GenericUrl(DATABASE_URL_STRING + '/' + PATH + ".json");
 
-    private HttpClient httpClient;
-    private RemoteDatabaseClient client;
+    private FirebaseDatabase database;
     private NodePath path;
     private NodeValue value;
 
@@ -91,9 +89,9 @@ static void initFirebase() {
 
     @BeforeEach
     void setUp() {
-        httpClient = mock(HttpClient.class);
-        FirebaseDatabase mockFirebase = mock(FirebaseDatabase.class);
-        client = new RemoteDatabaseClient(mockFirebase, NODE_FACTORY, httpClient);
+        database = FirebaseDatabase.getInstance(
+                FirebaseApp.getInstance(FIREBASE_APP_NAME)
+        );
         path = NodePaths.of(PATH);
         value = DATA.asNodeValue();
     }
@@ -101,6 +99,7 @@ void setUp() {
     @Test
     @DisplayName(NOT_ACCEPT_NULLS)
     void passNullToleranceCheck() {
+        FirebaseClient client = new RemoteDatabaseClient(database, NODE_FACTORY, noOpClient());
         new NullPointerTester()
                 .setDefault(NodePath.class, path)
                 .setDefault(NodeValue.class, value)
@@ -110,7 +109,8 @@ void passNullToleranceCheck() {
     @Test
     @DisplayName("retrieve data from given database path")
     void getData() {
-        when(httpClient.get(any())).thenReturn(DATA.value());
+        HttpClient httpClient = mockHttpClient(DATA.value());
+        FirebaseClient client = new RemoteDatabaseClient(database, NODE_FACTORY, httpClient);
 
         Optional<NodeValue> result = client.fetchNode(path);
         assertTrue(result.isPresent());
@@ -123,7 +123,8 @@ void getData() {
     @Test
     @DisplayName("return empty Optional in case of null data")
     void getNullData() {
-        when(httpClient.get(any())).thenReturn(NULL_ENTRY);
+        HttpClient httpClient = mockHttpClient(NULL_ENTRY);
+        FirebaseClient client = new RemoteDatabaseClient(database, NODE_FACTORY, httpClient);
 
         Optional<NodeValue> result = client.fetchNode(path);
         assertFalse(result.isPresent());
@@ -132,19 +133,25 @@ void getNullData() {
     @Test
     @DisplayName("store data via PUT method when node is not present")
     void storeNewViaPut() {
-        when(httpClient.get(any())).thenReturn(NULL_ENTRY);
+        HttpClient httpClient = mockHttpClient(NULL_ENTRY, (method, url) -> {
+            assertThat(method).isEqualTo(HttpMethods.PUT);
+            assertThat(url).isEqualTo(EXPECTED_NODE_URL.build());
+        });
+        FirebaseClient client = new RemoteDatabaseClient(database, NODE_FACTORY, httpClient);
 
         client.create(path, value);
-        verify(httpClient).put(eq(EXPECTED_NODE_URL), any(ByteArrayContent.class));
     }
 
     @Test
     @DisplayName("store data via PATCH method when node already exists")
     void updateExistingViaPatch() {
-        when(httpClient.get(any())).thenReturn(DATA.value());
+        HttpClient httpClient = mockHttpClient(NULL_ENTRY, (method, url) -> {
+            assertThat(method).isEqualTo(HttpMethods.PATCH);
+            assertThat(url).isEqualTo(EXPECTED_NODE_URL.build());
+        });
+        FirebaseClient client = new RemoteDatabaseClient(database, NODE_FACTORY, httpClient);
 
         client.update(path, value);
-        verify(httpClient).patch(eq(EXPECTED_NODE_URL), any(ByteArrayContent.class));
     }
 
     @Nested

From 2c677057a7ad90c524af420e5ae623c9dc2f49c1 Mon Sep 17 00:00:00 2001
From: Yuri Sergiichuk <yuri.sergiichuk@teamdev.com>
Date: Mon, 7 Dec 2020 12:20:19 +0200
Subject: [PATCH 18/41] Suppress PMD warnings.

---
 testutil-web/src/main/java/io/spine/web/given/MockedRequest.java | 1 +
 .../src/main/java/io/spine/web/given/MockedResponse.java         | 1 +
 2 files changed, 2 insertions(+)

diff --git a/testutil-web/src/main/java/io/spine/web/given/MockedRequest.java b/testutil-web/src/main/java/io/spine/web/given/MockedRequest.java
index 7eefb9ed8..87d21b0c3 100644
--- a/testutil-web/src/main/java/io/spine/web/given/MockedRequest.java
+++ b/testutil-web/src/main/java/io/spine/web/given/MockedRequest.java
@@ -34,6 +34,7 @@
  * @apiNote Some of the methods are marked as {@linkplain Deprecated deprecated} to avoid
  *         the deprecation warnings, as their {@code super} methods are marked as such.
  */
+@SuppressWarnings("PMD.UncommentedEmptyMethodBody") // default implementations are empty on purpose.
 public interface MockedRequest extends HttpServletRequest {
 
     @Override
diff --git a/testutil-web/src/main/java/io/spine/web/given/MockedResponse.java b/testutil-web/src/main/java/io/spine/web/given/MockedResponse.java
index 24ce2b0f7..c09e6c8c4 100644
--- a/testutil-web/src/main/java/io/spine/web/given/MockedResponse.java
+++ b/testutil-web/src/main/java/io/spine/web/given/MockedResponse.java
@@ -21,6 +21,7 @@
  * @apiNote Some of the methods are marked as {@linkplain Deprecated deprecated} to avoid
  *         the deprecation warnings, as their {@code super} methods are marked as such.
  */
+@SuppressWarnings("PMD.UncommentedEmptyMethodBody") // default implementations are empty on purpose.
 public interface MockedResponse extends HttpServletResponse {
 
     @Override

From ae9f283add2fe3ef6693faa12ba7b42c3f79aff7 Mon Sep 17 00:00:00 2001
From: Yuri Sergiichuk <yuri.sergiichuk@teamdev.com>
Date: Mon, 7 Dec 2020 12:20:31 +0200
Subject: [PATCH 19/41] Update JS versions.

---
 client-js/package.json                  | 2 +-
 integration-tests/js-tests/package.json | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/client-js/package.json b/client-js/package.json
index 89d1a7f4c..bd334d12b 100644
--- a/client-js/package.json
+++ b/client-js/package.json
@@ -1,6 +1,6 @@
 {
   "name": "spine-web",
-  "version": "1.6.15",
+  "version": "1.6.16",
   "license": "Apache-2.0",
   "description": "A JS client for interacting with Spine applications.",
   "homepage": "https://spine.io",
diff --git a/integration-tests/js-tests/package.json b/integration-tests/js-tests/package.json
index ff5b0a466..b2551caf6 100644
--- a/integration-tests/js-tests/package.json
+++ b/integration-tests/js-tests/package.json
@@ -1,6 +1,6 @@
 {
   "name": "client-js-tests",
-  "version": "1.6.15",
+  "version": "1.6.16",
   "license": "Apache-2.0",
   "description": "Tests of a `spine-web` JS library against the Spine-based application.",
   "scripts": {

From 5be0cee3e36e78cc15e86243c7ea2bce4fbcaa16 Mon Sep 17 00:00:00 2001
From: Yuri Sergiichuk <yuri.sergiichuk@teamdev.com>
Date: Mon, 7 Dec 2020 12:21:18 +0200
Subject: [PATCH 20/41] Update reports.

---
 license-report.md | 303 ++++++++++++----------------------------------
 pom.xml           |  67 ++++------
 2 files changed, 103 insertions(+), 267 deletions(-)

diff --git a/license-report.md b/license-report.md
index 1661bff8f..f7546c2d4 100644
--- a/license-report.md
+++ b/license-report.md
@@ -1,6 +1,6 @@
 
     
-# Dependencies of `io.spine:spine-client-js:1.6.15`
+# Dependencies of `io.spine:spine-client-js:1.6.16`
 
 ## Runtime
 1. **Group:** com.google.code.findbugs **Name:** jsr305 **Version:** 3.0.2
@@ -10,9 +10,6 @@
 1. **Group:** com.google.errorprone **Name:** error_prone_annotations **Version:** 2.4.0
      * **POM License: Apache 2.0** - [http://www.apache.org/licenses/LICENSE-2.0.txt](http://www.apache.org/licenses/LICENSE-2.0.txt)
 
-1. **Group:** com.google.errorprone **Name:** error_prone_type_annotations **Version:** 2.4.0
-     * **POM License: Apache 2.0** - [http://www.apache.org/licenses/LICENSE-2.0.txt](http://www.apache.org/licenses/LICENSE-2.0.txt)
-
 1. **Group:** com.google.guava **Name:** failureaccess **Version:** 1.0.1
      * **Manifest Project URL:** [https://github.com/google/guava/](https://github.com/google/guava/)
      * **POM License: The Apache Software License, Version 2.0** - [http://www.apache.org/licenses/LICENSE-2.0.txt](http://www.apache.org/licenses/LICENSE-2.0.txt)
@@ -220,12 +217,6 @@
      * **POM Project URL:** [http://junit.org](http://junit.org)
      * **POM License: Eclipse Public License 1.0** - [http://www.eclipse.org/legal/epl-v10.html](http://www.eclipse.org/legal/epl-v10.html)
 
-1. **Group:** net.bytebuddy **Name:** byte-buddy **Version:** 1.7.9
-     * **POM License: The Apache Software License, Version 2.0** - [http://www.apache.org/licenses/LICENSE-2.0.txt](http://www.apache.org/licenses/LICENSE-2.0.txt)
-
-1. **Group:** net.bytebuddy **Name:** byte-buddy-agent **Version:** 1.7.9
-     * **POM License: The Apache Software License, Version 2.0** - [http://www.apache.org/licenses/LICENSE-2.0.txt](http://www.apache.org/licenses/LICENSE-2.0.txt)
-
 1. **Group:** net.java.dev.javacc **Name:** javacc **Version:** 5.0
      * **POM Project URL:** [https://javacc.dev.java.net/](https://javacc.dev.java.net/)
      * **POM License: Berkeley Software Distribution (BSD) License** - [http://www.opensource.org/licenses/bsd-license.html](http://www.opensource.org/licenses/bsd-license.html)
@@ -280,9 +271,6 @@
      * **POM License: MIT license** - [http://www.opensource.org/licenses/mit-license.php](http://www.opensource.org/licenses/mit-license.php)
      * **POM License: The Apache Software License, Version 2.0** - [http://www.apache.org/licenses/LICENSE-2.0.txt](http://www.apache.org/licenses/LICENSE-2.0.txt)
 
-1. **Group:** org.hamcrest **Name:** hamcrest-all **Version:** 1.3
-     * **POM License: New BSD License** - [http://www.opensource.org/licenses/bsd-license.php](http://www.opensource.org/licenses/bsd-license.php)
-
 1. **Group:** org.hamcrest **Name:** hamcrest-core **Version:** 1.3
      * **POM License: New BSD License** - [http://www.opensource.org/licenses/bsd-license.php](http://www.opensource.org/licenses/bsd-license.php)
 
@@ -319,14 +307,6 @@
      * **POM Project URL:** [https://junit.org/junit5/](https://junit.org/junit5/)
      * **POM License: Eclipse Public License v2.0** - [https://www.eclipse.org/legal/epl-v20.html](https://www.eclipse.org/legal/epl-v20.html)
 
-1. **Group:** org.mockito **Name:** mockito-core **Version:** 2.12.0
-     * **POM Project URL:** [https://github.com/mockito/mockito](https://github.com/mockito/mockito)
-     * **POM License: The MIT License** - [https://github.com/mockito/mockito/blob/master/LICENSE](https://github.com/mockito/mockito/blob/master/LICENSE)
-
-1. **Group:** org.objenesis **Name:** objenesis **Version:** 2.6
-     * **POM Project URL:** [http://objenesis.org](http://objenesis.org)
-     * **POM License: Apache 2** - [http://www.apache.org/licenses/LICENSE-2.0.txt](http://www.apache.org/licenses/LICENSE-2.0.txt)
-
 1. **Group:** org.opentest4j **Name:** opentest4j **Version:** 1.2.0
      * **Manifest License:** The Apache License, Version 2.0 (Not packaged)
      * **POM Project URL:** [https://github.com/ota4j-team/opentest4j](https://github.com/ota4j-team/opentest4j)
@@ -388,17 +368,17 @@
  The dependencies distributed under several licenses, are used according their commercial-use-friendly license.
 
 
-This report was generated on **Mon Nov 23 17:08:56 EET 2020** using [Gradle-License-Report plugin](https://github.com/jk1/Gradle-License-Report) by Evgeny Naumenko, licensed under [Apache 2.0 License](https://github.com/jk1/Gradle-License-Report/blob/master/LICENSE).
+This report was generated on **Mon Dec 07 12:18:22 EET 2020** using [Gradle-License-Report plugin](https://github.com/jk1/Gradle-License-Report) by Evgeny Naumenko, licensed under [Apache 2.0 License](https://github.com/jk1/Gradle-License-Report/blob/master/LICENSE).
 
 
-#NPM dependencies of `spine-web@1.6.15`
+#NPM dependencies of `spine-web@1.6.16`
 
 ## `Production` dependencies:
 
 1. **base64-js@1.3.1**
      * Licenses: MIT
      * Repository: [https://github.com/beatgammit/base64-js](https://github.com/beatgammit/base64-js)
-1. **google-protobuf@3.14.0**
+1. **google-protobuf@3.13.0**
      * Licenses: BSD-3-Clause
      * Repository: [https://github.com/protocolbuffers/protobuf/tree/master/js](https://github.com/protocolbuffers/protobuf/tree/master/js)
 1. **isomorphic-fetch@3.0.0**
@@ -410,7 +390,7 @@ This report was generated on **Mon Nov 23 17:08:56 EET 2020** using [Gradle-Lice
 1. **rxjs@6.5.5**
      * Licenses: Apache-2.0
      * Repository: [https://github.com/reactivex/rxjs](https://github.com/reactivex/rxjs)
-1. **spine-web@1.6.15**
+1. **spine-web@1.6.16**
      * Licenses: Apache-2.0
      * Repository: [https://github.com/SpineEventEngine/web](https://github.com/SpineEventEngine/web)
 1. **tslib@1.14.1**
@@ -419,7 +399,7 @@ This report was generated on **Mon Nov 23 17:08:56 EET 2020** using [Gradle-Lice
 1. **uuid@8.3.1**
      * Licenses: MIT
      * Repository: [https://github.com/uuidjs/uuid](https://github.com/uuidjs/uuid)
-1. **whatwg-fetch@3.5.0**
+1. **whatwg-fetch@3.4.1**
      * Licenses: MIT
      * Repository: [https://github.com/github/fetch](https://github.com/github/fetch)
 
@@ -427,16 +407,16 @@ This report was generated on **Mon Nov 23 17:08:56 EET 2020** using [Gradle-Lice
 
 ## `Development` dependencies:
 
-1. **@babel/cli@7.12.7**
+1. **@babel/cli@7.12.1**
      * Licenses: MIT
      * Repository: [https://github.com/babel/babel](https://github.com/babel/babel)
 1. **@babel/code-frame@7.10.4**
      * Licenses: MIT
      * Repository: [https://github.com/babel/babel](https://github.com/babel/babel)
-1. **@babel/compat-data@7.12.7**
+1. **@babel/compat-data@7.12.5**
      * Licenses: MIT
      * Repository: [https://github.com/babel/babel](https://github.com/babel/babel)
-1. **@babel/core@7.12.7**
+1. **@babel/core@7.12.3**
      * Licenses: MIT
      * Repository: [https://github.com/babel/babel](https://github.com/babel/babel)
 1. **@babel/generator@7.12.5**
@@ -454,7 +434,7 @@ This report was generated on **Mon Nov 23 17:08:56 EET 2020** using [Gradle-Lice
 1. **@babel/helper-create-class-features-plugin@7.12.1**
      * Licenses: MIT
      * Repository: [https://github.com/babel/babel](https://github.com/babel/babel)
-1. **@babel/helper-create-regexp-features-plugin@7.12.7**
+1. **@babel/helper-create-regexp-features-plugin@7.12.1**
      * Licenses: MIT
      * Repository: [https://github.com/babel/babel](https://github.com/babel/babel)
 1. **@babel/helper-define-map@7.10.5**
@@ -472,7 +452,7 @@ This report was generated on **Mon Nov 23 17:08:56 EET 2020** using [Gradle-Lice
 1. **@babel/helper-hoist-variables@7.10.4**
      * Licenses: MIT
      * Repository: [https://github.com/babel/babel](https://github.com/babel/babel)
-1. **@babel/helper-member-expression-to-functions@7.12.7**
+1. **@babel/helper-member-expression-to-functions@7.12.1**
      * Licenses: MIT
      * Repository: [https://github.com/babel/babel](https://github.com/babel/babel)
 1. **@babel/helper-module-imports@7.12.5**
@@ -481,12 +461,15 @@ This report was generated on **Mon Nov 23 17:08:56 EET 2020** using [Gradle-Lice
 1. **@babel/helper-module-transforms@7.12.1**
      * Licenses: MIT
      * Repository: [https://github.com/babel/babel](https://github.com/babel/babel)
-1. **@babel/helper-optimise-call-expression@7.12.7**
+1. **@babel/helper-optimise-call-expression@7.10.4**
      * Licenses: MIT
      * Repository: [https://github.com/babel/babel](https://github.com/babel/babel)
 1. **@babel/helper-plugin-utils@7.10.4**
      * Licenses: MIT
      * Repository: [https://github.com/babel/babel](https://github.com/babel/babel)
+1. **@babel/helper-regex@7.10.5**
+     * Licenses: MIT
+     * Repository: [https://github.com/babel/babel](https://github.com/babel/babel)
 1. **@babel/helper-remap-async-to-generator@7.12.1**
      * Licenses: MIT
      * Repository: [https://github.com/babel/babel](https://github.com/babel/babel)
@@ -517,7 +500,7 @@ This report was generated on **Mon Nov 23 17:08:56 EET 2020** using [Gradle-Lice
 1. **@babel/highlight@7.10.4**
      * Licenses: MIT
      * Repository: [https://github.com/babel/babel](https://github.com/babel/babel)
-1. **@babel/parser@7.12.7**
+1. **@babel/parser@7.12.5**
      * Licenses: MIT
      * Repository: [https://github.com/babel/babel](https://github.com/babel/babel)
 1. **@babel/plugin-proposal-async-generator-functions@7.12.1**
@@ -541,7 +524,7 @@ This report was generated on **Mon Nov 23 17:08:56 EET 2020** using [Gradle-Lice
 1. **@babel/plugin-proposal-nullish-coalescing-operator@7.12.1**
      * Licenses: MIT
      * Repository: [https://github.com/babel/babel](https://github.com/babel/babel)
-1. **@babel/plugin-proposal-numeric-separator@7.12.7**
+1. **@babel/plugin-proposal-numeric-separator@7.12.5**
      * Licenses: MIT
      * Repository: [https://github.com/babel/babel](https://github.com/babel/babel)
 1. **@babel/plugin-proposal-object-rest-spread@7.12.1**
@@ -550,7 +533,7 @@ This report was generated on **Mon Nov 23 17:08:56 EET 2020** using [Gradle-Lice
 1. **@babel/plugin-proposal-optional-catch-binding@7.12.1**
      * Licenses: MIT
      * Repository: [https://github.com/babel/babel](https://github.com/babel/babel)
-1. **@babel/plugin-proposal-optional-chaining@7.12.7**
+1. **@babel/plugin-proposal-optional-chaining@7.12.1**
      * Licenses: MIT
      * Repository: [https://github.com/babel/babel](https://github.com/babel/babel)
 1. **@babel/plugin-proposal-private-methods@7.12.1**
@@ -676,7 +659,7 @@ This report was generated on **Mon Nov 23 17:08:56 EET 2020** using [Gradle-Lice
 1. **@babel/plugin-transform-spread@7.12.1**
      * Licenses: MIT
      * Repository: [https://github.com/babel/babel](https://github.com/babel/babel)
-1. **@babel/plugin-transform-sticky-regex@7.12.7**
+1. **@babel/plugin-transform-sticky-regex@7.12.1**
      * Licenses: MIT
      * Repository: [https://github.com/babel/babel](https://github.com/babel/babel)
 1. **@babel/plugin-transform-template-literals@7.12.1**
@@ -691,7 +674,7 @@ This report was generated on **Mon Nov 23 17:08:56 EET 2020** using [Gradle-Lice
 1. **@babel/plugin-transform-unicode-regex@7.12.1**
      * Licenses: MIT
      * Repository: [https://github.com/babel/babel](https://github.com/babel/babel)
-1. **@babel/preset-env@7.12.7**
+1. **@babel/preset-env@7.12.1**
      * Licenses: MIT
      * Repository: [https://github.com/babel/babel](https://github.com/babel/babel)
 1. **@babel/preset-modules@0.1.4**
@@ -703,13 +686,13 @@ This report was generated on **Mon Nov 23 17:08:56 EET 2020** using [Gradle-Lice
 1. **@babel/runtime@7.12.5**
      * Licenses: MIT
      * Repository: [https://github.com/babel/babel](https://github.com/babel/babel)
-1. **@babel/template@7.12.7**
+1. **@babel/template@7.10.4**
      * Licenses: MIT
      * Repository: [https://github.com/babel/babel](https://github.com/babel/babel)
-1. **@babel/traverse@7.12.7**
+1. **@babel/traverse@7.12.5**
      * Licenses: MIT
      * Repository: [https://github.com/babel/babel](https://github.com/babel/babel)
-1. **@babel/types@7.12.7**
+1. **@babel/types@7.12.6**
      * Licenses: MIT
      * Repository: [https://github.com/babel/babel](https://github.com/babel/babel)
 1. **@firebase/analytics-types@0.4.0**
@@ -796,19 +779,22 @@ This report was generated on **Mon Nov 23 17:08:56 EET 2020** using [Gradle-Lice
 1. **@firebase/webchannel-wrapper@0.4.0**
      * Licenses: Apache-2.0
      * Repository: [https://github.com/firebase/firebase-js-sdk](https://github.com/firebase/firebase-js-sdk)
-1. **@grpc/grpc-js@1.2.1**
+1. **@grpc/grpc-js@1.1.8**
      * Licenses: Apache-2.0
      * Repository: [https://github.com/grpc/grpc-node/tree/master/packages/grpc-js](https://github.com/grpc/grpc-node/tree/master/packages/grpc-js)
 1. **@grpc/proto-loader@0.5.5**
      * Licenses: Apache-2.0
      * Repository: [https://github.com/grpc/grpc-node](https://github.com/grpc/grpc-node)
+1. **@grpc/proto-loader@0.6.0-pre9**
+     * Licenses: Apache-2.0
+     * Repository: [https://github.com/grpc/grpc-node](https://github.com/grpc/grpc-node)
 1. **@istanbuljs/load-nyc-config@1.1.0**
      * Licenses: ISC
      * Repository: [https://github.com/istanbuljs/load-nyc-config](https://github.com/istanbuljs/load-nyc-config)
 1. **@istanbuljs/schema@0.1.2**
      * Licenses: MIT
      * Repository: [https://github.com/istanbuljs/schema](https://github.com/istanbuljs/schema)
-1. **@nicolo-ribaudo/chokidar-2@2.1.8-no-fsevents**
+1. **@nicolo-ribaudo/chokidar-2@2.1.8**
      * Licenses: MIT
      * Repository: [https://github.com/nicolo-ribaudo/chokidar-2](https://github.com/nicolo-ribaudo/chokidar-2)
 1. **@protobufjs/aspromise@1.1.2**
@@ -850,7 +836,7 @@ This report was generated on **Mon Nov 23 17:08:56 EET 2020** using [Gradle-Lice
 1. **@sinonjs/formatio@5.0.1**
      * Licenses: BSD-3-Clause
      * Repository: [https://github.com/sinonjs/formatio](https://github.com/sinonjs/formatio)
-1. **@sinonjs/samsam@5.3.0**
+1. **@sinonjs/samsam@5.2.0**
      * Licenses: BSD-3-Clause
      * Repository: [https://github.com/sinonjs/samsam](https://github.com/sinonjs/samsam)
 1. **@sinonjs/text-encoding@0.7.1**
@@ -859,19 +845,16 @@ This report was generated on **Mon Nov 23 17:08:56 EET 2020** using [Gradle-Lice
 1. **@tootallnate/once@1.1.2**
      * Licenses: MIT
      * Repository: [https://github.com/TooTallNate/once](https://github.com/TooTallNate/once)
-1. **@types/color-name@1.1.1**
-     * Licenses: MIT
-     * Repository: [https://github.com/DefinitelyTyped/DefinitelyTyped](https://github.com/DefinitelyTyped/DefinitelyTyped)
 1. **@types/json-schema@7.0.6**
      * Licenses: MIT
      * Repository: [https://github.com/DefinitelyTyped/DefinitelyTyped](https://github.com/DefinitelyTyped/DefinitelyTyped)
 1. **@types/long@4.0.1**
      * Licenses: MIT
      * Repository: [https://github.com/DefinitelyTyped/DefinitelyTyped](https://github.com/DefinitelyTyped/DefinitelyTyped)
-1. **@types/node@12.19.6**
+1. **@types/node@12.19.3**
      * Licenses: MIT
      * Repository: [https://github.com/DefinitelyTyped/DefinitelyTyped](https://github.com/DefinitelyTyped/DefinitelyTyped)
-1. **@types/node@13.13.32**
+1. **@types/node@13.13.30**
      * Licenses: MIT
      * Repository: [https://github.com/DefinitelyTyped/DefinitelyTyped](https://github.com/DefinitelyTyped/DefinitelyTyped)
 1. **@ungap/promise-all-settled@1.1.2**
@@ -958,7 +941,7 @@ This report was generated on **Mon Nov 23 17:08:56 EET 2020** using [Gradle-Lice
 1. **agent-base@6.0.2**
      * Licenses: MIT
      * Repository: [https://github.com/TooTallNate/node-agent-base](https://github.com/TooTallNate/node-agent-base)
-1. **aggregate-error@3.0.1**
+1. **aggregate-error@3.1.0**
      * Licenses: MIT
      * Repository: [https://github.com/sindresorhus/aggregate-error](https://github.com/sindresorhus/aggregate-error)
 1. **ajv-errors@1.0.1**
@@ -991,9 +974,6 @@ This report was generated on **Mon Nov 23 17:08:56 EET 2020** using [Gradle-Lice
 1. **ansi-styles@3.2.1**
      * Licenses: MIT
      * Repository: [https://github.com/chalk/ansi-styles](https://github.com/chalk/ansi-styles)
-1. **ansi-styles@4.2.1**
-     * Licenses: MIT
-     * Repository: [https://github.com/chalk/ansi-styles](https://github.com/chalk/ansi-styles)
 1. **ansi-styles@4.3.0**
      * Licenses: MIT
      * Repository: [https://github.com/chalk/ansi-styles](https://github.com/chalk/ansi-styles)
@@ -1060,7 +1040,7 @@ This report was generated on **Mon Nov 23 17:08:56 EET 2020** using [Gradle-Lice
 1. **babel-code-frame@6.26.0**
      * Licenses: MIT
      * Repository: [https://github.com/babel/babel/tree/master/packages/babel-code-frame](https://github.com/babel/babel/tree/master/packages/babel-code-frame)
-1. **babel-loader@8.2.1**
+1. **babel-loader@8.1.0**
      * Licenses: MIT
      * Repository: [https://github.com/babel/babel-loader](https://github.com/babel/babel-loader)
 1. **babel-messages@6.23.0**
@@ -1108,9 +1088,6 @@ This report was generated on **Mon Nov 23 17:08:56 EET 2020** using [Gradle-Lice
 1. **binary-extensions@2.1.0**
      * Licenses: MIT
      * Repository: [https://github.com/sindresorhus/binary-extensions](https://github.com/sindresorhus/binary-extensions)
-1. **bindings@1.5.0**
-     * Licenses: MIT
-     * Repository: [https://github.com/TooTallNate/node-bindings](https://github.com/TooTallNate/node-bindings)
 1. **bluebird@3.7.2**
      * Licenses: MIT
      * Repository: [https://github.com/petkaantonov/bluebird](https://github.com/petkaantonov/bluebird)
@@ -1144,7 +1121,7 @@ This report was generated on **Mon Nov 23 17:08:56 EET 2020** using [Gradle-Lice
 1. **browserify-des@1.0.2**
      * Licenses: MIT
      * Repository: [https://github.com/crypto-browserify/browserify-des](https://github.com/crypto-browserify/browserify-des)
-1. **browserify-rsa@4.1.0**
+1. **browserify-rsa@4.0.1**
      * Licenses: MIT
      * Repository: [https://github.com/crypto-browserify/browserify-rsa](https://github.com/crypto-browserify/browserify-rsa)
 1. **browserify-sign@4.2.1**
@@ -1153,7 +1130,7 @@ This report was generated on **Mon Nov 23 17:08:56 EET 2020** using [Gradle-Lice
 1. **browserify-zlib@0.2.0**
      * Licenses: MIT
      * Repository: [https://github.com/devongovett/browserify-zlib](https://github.com/devongovett/browserify-zlib)
-1. **browserslist@4.14.7**
+1. **browserslist@4.14.6**
      * Licenses: MIT
      * Repository: [https://github.com/browserslist/browserslist](https://github.com/browserslist/browserslist)
 1. **buffer-equal-constant-time@1.0.1**
@@ -1189,7 +1166,7 @@ This report was generated on **Mon Nov 23 17:08:56 EET 2020** using [Gradle-Lice
 1. **camelcase@6.2.0**
      * Licenses: MIT
      * Repository: [https://github.com/sindresorhus/camelcase](https://github.com/sindresorhus/camelcase)
-1. **caniuse-lite@1.0.30001159**
+1. **caniuse-lite@1.0.30001156**
      * Licenses: CC-BY-4.0
      * Repository: [https://github.com/ben-eb/caniuse-lite](https://github.com/ben-eb/caniuse-lite)
 1. **catharsis@0.8.11**
@@ -1252,7 +1229,7 @@ This report was generated on **Mon Nov 23 17:08:56 EET 2020** using [Gradle-Lice
 1. **colorette@1.2.1**
      * Licenses: MIT
      * Repository: [https://github.com/jorgebucaran/colorette](https://github.com/jorgebucaran/colorette)
-1. **command-line-usage@6.1.1**
+1. **command-line-usage@6.1.0**
      * Licenses: MIT
      * Repository: [https://github.com/75lb/command-line-usage](https://github.com/75lb/command-line-usage)
 1. **commander@2.20.3**
@@ -1291,7 +1268,7 @@ This report was generated on **Mon Nov 23 17:08:56 EET 2020** using [Gradle-Lice
 1. **copy-descriptor@0.1.1**
      * Licenses: MIT
      * Repository: [https://github.com/jonschlinkert/copy-descriptor](https://github.com/jonschlinkert/copy-descriptor)
-1. **core-js-compat@3.7.0**
+1. **core-js-compat@3.6.5**
      * Licenses: MIT
      * Repository: [https://github.com/zloirock/core-js](https://github.com/zloirock/core-js)
 1. **core-js@2.6.11**
@@ -1327,15 +1304,9 @@ This report was generated on **Mon Nov 23 17:08:56 EET 2020** using [Gradle-Lice
 1. **debug@3.2.6**
      * Licenses: MIT
      * Repository: [https://github.com/visionmedia/debug](https://github.com/visionmedia/debug)
-1. **debug@4.1.1**
-     * Licenses: MIT
-     * Repository: [https://github.com/visionmedia/debug](https://github.com/visionmedia/debug)
 1. **debug@4.2.0**
      * Licenses: MIT
      * Repository: [https://github.com/visionmedia/debug](https://github.com/visionmedia/debug)
-1. **debug@4.3.1**
-     * Licenses: MIT
-     * Repository: [https://github.com/visionmedia/debug](https://github.com/visionmedia/debug)
 1. **debuglog@1.0.1**
      * Licenses: MIT
      * Repository: [https://github.com/sam-github/node-debuglog](https://github.com/sam-github/node-debuglog)
@@ -1390,7 +1361,7 @@ This report was generated on **Mon Nov 23 17:08:56 EET 2020** using [Gradle-Lice
 1. **ecdsa-sig-formatter@1.0.11**
      * Licenses: Apache-2.0
      * Repository: [https://github.com/Brightspace/node-ecdsa-sig-formatter](https://github.com/Brightspace/node-ecdsa-sig-formatter)
-1. **electron-to-chromium@1.3.603**
+1. **electron-to-chromium@1.3.588**
      * Licenses: ISC
      * Repository: [https://github.com/kilian/electron-to-chromium](https://github.com/kilian/electron-to-chromium)
 1. **elliptic@6.5.3**
@@ -1498,9 +1469,6 @@ This report was generated on **Mon Nov 23 17:08:56 EET 2020** using [Gradle-Lice
 1. **figgy-pudding@3.5.2**
      * Licenses: ISC
      * Repository: [https://github.com/npm/figgy-pudding](https://github.com/npm/figgy-pudding)
-1. **file-uri-to-path@1.0.0**
-     * Licenses: MIT
-     * Repository: [https://github.com/TooTallNate/file-uri-to-path](https://github.com/TooTallNate/file-uri-to-path)
 1. **fill-range@4.0.0**
      * Licenses: MIT
      * Repository: [https://github.com/jonschlinkert/fill-range](https://github.com/jonschlinkert/fill-range)
@@ -1546,7 +1514,7 @@ This report was generated on **Mon Nov 23 17:08:56 EET 2020** using [Gradle-Lice
 1. **from2@2.3.0**
      * Licenses: MIT
      * Repository: [https://github.com/hughsk/from2](https://github.com/hughsk/from2)
-1. **fromentries@1.2.0**
+1. **fromentries@1.3.2**
      * Licenses: MIT
      * Repository: [https://github.com/feross/fromentries](https://github.com/feross/fromentries)
 1. **fs-readdir-recursive@1.1.0**
@@ -1558,12 +1526,6 @@ This report was generated on **Mon Nov 23 17:08:56 EET 2020** using [Gradle-Lice
 1. **fs.realpath@1.0.0**
      * Licenses: ISC
      * Repository: [https://github.com/isaacs/fs.realpath](https://github.com/isaacs/fs.realpath)
-1. **fsevents@1.2.13**
-     * Licenses: MIT
-     * Repository: [https://github.com/strongloop/fsevents](https://github.com/strongloop/fsevents)
-1. **fsevents@2.1.3**
-     * Licenses: MIT
-     * Repository: [https://github.com/fsevents/fsevents](https://github.com/fsevents/fsevents)
 1. **function-bind@1.1.1**
      * Licenses: MIT
      * Repository: [https://github.com/Raynos/function-bind](https://github.com/Raynos/function-bind)
@@ -1612,13 +1574,13 @@ This report was generated on **Mon Nov 23 17:08:56 EET 2020** using [Gradle-Lice
 1. **google-p12-pem@3.0.3**
      * Licenses: MIT
      * Repository: [https://github.com/google/google-p12-pem](https://github.com/google/google-p12-pem)
-1. **graceful-fs@4.2.3**
+1. **graceful-fs@4.2.4**
      * Licenses: ISC
      * Repository: [https://github.com/isaacs/node-graceful-fs](https://github.com/isaacs/node-graceful-fs)
 1. **growl@1.10.5**
      * Licenses: MIT
      * Repository: [https://github.com/tj/node-growl](https://github.com/tj/node-growl)
-1. **gtoken@5.1.0**
+1. **gtoken@5.0.5**
      * Licenses: MIT
      * Repository: [https://github.com/google/node-gtoken](https://github.com/google/node-gtoken)
 1. **has-ansi@2.0.0**
@@ -1654,7 +1616,7 @@ This report was generated on **Mon Nov 23 17:08:56 EET 2020** using [Gradle-Lice
 1. **hash.js@1.1.7**
      * Licenses: MIT
      * Repository: [https://github.com/indutny/hash.js](https://github.com/indutny/hash.js)
-1. **hasha@5.2.0**
+1. **hasha@5.2.2**
      * Licenses: MIT
      * Repository: [https://github.com/sindresorhus/hasha](https://github.com/sindresorhus/hasha)
 1. **he@1.2.0**
@@ -1744,6 +1706,9 @@ This report was generated on **Mon Nov 23 17:08:56 EET 2020** using [Gradle-Lice
 1. **is-buffer@1.1.6**
      * Licenses: MIT
      * Repository: [https://github.com/feross/is-buffer](https://github.com/feross/is-buffer)
+1. **is-core-module@2.1.0**
+     * Licenses: MIT
+     * Repository: [https://github.com/inspect-js/is-core-module](https://github.com/inspect-js/is-core-module)
 1. **is-data-descriptor@0.1.4**
      * Licenses: MIT
      * Repository: [https://github.com/jonschlinkert/is-data-descriptor](https://github.com/jonschlinkert/is-data-descriptor)
@@ -1843,9 +1808,6 @@ This report was generated on **Mon Nov 23 17:08:56 EET 2020** using [Gradle-Lice
 1. **js-tokens@4.0.0**
      * Licenses: MIT
      * Repository: [https://github.com/lydell/js-tokens](https://github.com/lydell/js-tokens)
-1. **js-yaml@3.13.1**
-     * Licenses: MIT
-     * Repository: [https://github.com/nodeca/js-yaml](https://github.com/nodeca/js-yaml)
 1. **js-yaml@3.14.0**
      * Licenses: MIT
      * Repository: [https://github.com/nodeca/js-yaml](https://github.com/nodeca/js-yaml)
@@ -1867,6 +1829,9 @@ This report was generated on **Mon Nov 23 17:08:56 EET 2020** using [Gradle-Lice
 1. **json-parse-better-errors@1.0.2**
      * Licenses: MIT
      * Repository: [https://github.com/zkat/json-parse-better-errors](https://github.com/zkat/json-parse-better-errors)
+1. **json-parse-even-better-errors@2.3.1**
+     * Licenses: MIT
+     * Repository: [https://github.com/npm/json-parse-even-better-errors](https://github.com/npm/json-parse-even-better-errors)
 1. **json-schema-traverse@0.4.1**
      * Licenses: MIT
      * Repository: [https://github.com/epoberezkin/json-schema-traverse](https://github.com/epoberezkin/json-schema-traverse)
@@ -1936,9 +1901,6 @@ This report was generated on **Mon Nov 23 17:08:56 EET 2020** using [Gradle-Lice
 1. **lodash.get@4.4.2**
      * Licenses: MIT
      * Repository: [https://github.com/lodash/lodash](https://github.com/lodash/lodash)
-1. **lodash@4.17.15**
-     * Licenses: MIT
-     * Repository: [https://github.com/lodash/lodash](https://github.com/lodash/lodash)
 1. **lodash@4.17.20**
      * Licenses: MIT
      * Repository: [https://github.com/lodash/lodash](https://github.com/lodash/lodash)
@@ -2014,9 +1976,6 @@ This report was generated on **Mon Nov 23 17:08:56 EET 2020** using [Gradle-Lice
 1. **minimatch@3.0.4**
      * Licenses: ISC
      * Repository: [https://github.com/isaacs/minimatch](https://github.com/isaacs/minimatch)
-1. **minimist@0.0.8**
-     * Licenses: MIT
-     * Repository: [https://github.com/substack/minimist](https://github.com/substack/minimist)
 1. **minimist@1.2.5**
      * Licenses: MIT
      * Repository: [https://github.com/substack/minimist](https://github.com/substack/minimist)
@@ -2026,9 +1985,6 @@ This report was generated on **Mon Nov 23 17:08:56 EET 2020** using [Gradle-Lice
 1. **mixin-deep@1.3.2**
      * Licenses: MIT
      * Repository: [https://github.com/jonschlinkert/mixin-deep](https://github.com/jonschlinkert/mixin-deep)
-1. **mkdirp@0.5.1**
-     * Licenses: MIT
-     * Repository: [https://github.com/substack/node-mkdirp](https://github.com/substack/node-mkdirp)
 1. **mkdirp@0.5.5**
      * Licenses: MIT
      * Repository: [https://github.com/substack/node-mkdirp](https://github.com/substack/node-mkdirp)
@@ -2047,9 +2003,6 @@ This report was generated on **Mon Nov 23 17:08:56 EET 2020** using [Gradle-Lice
 1. **ms@2.1.2**
      * Licenses: MIT
      * Repository: [https://github.com/zeit/ms](https://github.com/zeit/ms)
-1. **nan@2.14.2**
-     * Licenses: MIT
-     * Repository: [https://github.com/nodejs/nan](https://github.com/nodejs/nan)
 1. **nanoid@3.1.12**
      * Licenses: MIT
      * Repository: [https://github.com/ai/nanoid](https://github.com/ai/nanoid)
@@ -2062,6 +2015,9 @@ This report was generated on **Mon Nov 23 17:08:56 EET 2020** using [Gradle-Lice
 1. **nise@4.0.4**
      * Licenses: BSD-3-Clause
      * Repository: [https://github.com/sinonjs/nise](https://github.com/sinonjs/nise)
+1. **node-fetch@2.6.1**
+     * Licenses: MIT
+     * Repository: [https://github.com/bitinn/node-fetch](https://github.com/bitinn/node-fetch)
 1. **node-forge@0.10.0**
      * Licenses: (BSD-3-Clause OR GPL-2.0)
      * Repository: [https://github.com/digitalbazaar/forge](https://github.com/digitalbazaar/forge)
@@ -2074,7 +2030,7 @@ This report was generated on **Mon Nov 23 17:08:56 EET 2020** using [Gradle-Lice
 1. **node-preload@0.2.1**
      * Licenses: MIT
      * Repository: [https://github.com/cfware/node-preload](https://github.com/cfware/node-preload)
-1. **node-releases@1.1.67**
+1. **node-releases@1.1.65**
      * Licenses: MIT
      * Repository: [https://github.com/chicoxyzzy/node-releases](https://github.com/chicoxyzzy/node-releases)
 1. **nopt@4.0.3**
@@ -2134,7 +2090,7 @@ This report was generated on **Mon Nov 23 17:08:56 EET 2020** using [Gradle-Lice
 1. **osenv@0.1.5**
      * Licenses: ISC
      * Repository: [https://github.com/npm/osenv](https://github.com/npm/osenv)
-1. **p-limit@2.2.2**
+1. **p-limit@2.3.0**
      * Licenses: MIT
      * Repository: [https://github.com/sindresorhus/p-limit](https://github.com/sindresorhus/p-limit)
 1. **p-limit@3.0.2**
@@ -2233,7 +2189,7 @@ This report was generated on **Mon Nov 23 17:08:56 EET 2020** using [Gradle-Lice
 1. **promise-polyfill@8.1.3**
      * Licenses: MIT
      * Repository: [https://github.com/taylorhakes/promise-polyfill](https://github.com/taylorhakes/promise-polyfill)
-1. **protobufjs@6.10.2**
+1. **protobufjs@6.10.1**
      * Licenses: BSD-3-Clause
      * Repository: [https://github.com/protobufjs/protobuf.js](https://github.com/protobufjs/protobuf.js)
 1. **prr@1.0.1**
@@ -2275,7 +2231,7 @@ This report was generated on **Mon Nov 23 17:08:56 EET 2020** using [Gradle-Lice
 1. **read-installed@4.0.3**
      * Licenses: ISC
      * Repository: [https://github.com/isaacs/read-installed](https://github.com/isaacs/read-installed)
-1. **read-package-json@2.1.1**
+1. **read-package-json@2.1.2**
      * Licenses: ISC
      * Repository: [https://github.com/npm/read-package-json](https://github.com/npm/read-package-json)
 1. **readable-stream@2.3.7**
@@ -2359,7 +2315,7 @@ This report was generated on **Mon Nov 23 17:08:56 EET 2020** using [Gradle-Lice
 1. **resolve-url@0.2.1**
      * Licenses: MIT
      * Repository: [https://github.com/lydell/resolve-url](https://github.com/lydell/resolve-url)
-1. **resolve@1.15.1**
+1. **resolve@1.18.1**
      * Licenses: MIT
      * Repository: [https://github.com/browserify/resolve](https://github.com/browserify/resolve)
 1. **ret@0.1.15**
@@ -2428,7 +2384,7 @@ This report was generated on **Mon Nov 23 17:08:56 EET 2020** using [Gradle-Lice
 1. **shebang-regex@3.0.0**
      * Licenses: MIT
      * Repository: [https://github.com/sindresorhus/shebang-regex](https://github.com/sindresorhus/shebang-regex)
-1. **signal-exit@3.0.2**
+1. **signal-exit@3.0.3**
      * Licenses: ISC
      * Repository: [https://github.com/tapjs/signal-exit](https://github.com/tapjs/signal-exit)
 1. **sinon@9.2.1**
@@ -2473,25 +2429,25 @@ This report was generated on **Mon Nov 23 17:08:56 EET 2020** using [Gradle-Lice
 1. **spdx-compare@1.0.0**
      * Licenses: MIT
      * Repository: [https://github.com/kemitchell/spdx-compare.js](https://github.com/kemitchell/spdx-compare.js)
-1. **spdx-correct@3.1.0**
+1. **spdx-correct@3.1.1**
      * Licenses: Apache-2.0
      * Repository: [https://github.com/jslicense/spdx-correct.js](https://github.com/jslicense/spdx-correct.js)
-1. **spdx-exceptions@2.2.0**
+1. **spdx-exceptions@2.3.0**
      * Licenses: CC-BY-3.0
      * Repository: [https://github.com/kemitchell/spdx-exceptions.json](https://github.com/kemitchell/spdx-exceptions.json)
-1. **spdx-expression-parse@3.0.0**
+1. **spdx-expression-parse@3.0.1**
      * Licenses: MIT
      * Repository: [https://github.com/jslicense/spdx-expression-parse.js](https://github.com/jslicense/spdx-expression-parse.js)
-1. **spdx-license-ids@3.0.5**
+1. **spdx-license-ids@3.0.6**
      * Licenses: CC0-1.0
-     * Repository: [https://github.com/shinnn/spdx-license-ids](https://github.com/shinnn/spdx-license-ids)
+     * Repository: [https://github.com/jslicense/spdx-license-ids](https://github.com/jslicense/spdx-license-ids)
 1. **spdx-ranges@2.1.1**
      * Licenses: (MIT AND CC-BY-3.0)
      * Repository: [https://github.com/kemitchell/spdx-ranges.js](https://github.com/kemitchell/spdx-ranges.js)
 1. **spdx-satisfies@4.0.1**
      * Licenses: MIT
      * Repository: [https://github.com/kemitchell/spdx-satisfies.js](https://github.com/kemitchell/spdx-satisfies.js)
-1. **spine-web@1.6.15**
+1. **spine-web@1.6.16**
      * Licenses: Apache-2.0
      * Repository: [https://github.com/SpineEventEngine/web](https://github.com/SpineEventEngine/web)
 1. **split-string@3.1.0**
@@ -2563,9 +2519,6 @@ This report was generated on **Mon Nov 23 17:08:56 EET 2020** using [Gradle-Lice
 1. **supports-color@5.5.0**
      * Licenses: MIT
      * Repository: [https://github.com/chalk/supports-color](https://github.com/chalk/supports-color)
-1. **supports-color@7.1.0**
-     * Licenses: MIT
-     * Repository: [https://github.com/chalk/supports-color](https://github.com/chalk/supports-color)
 1. **supports-color@7.2.0**
      * Licenses: MIT
      * Repository: [https://github.com/chalk/supports-color](https://github.com/chalk/supports-color)
@@ -2710,10 +2663,10 @@ This report was generated on **Mon Nov 23 17:08:56 EET 2020** using [Gradle-Lice
 1. **vm-browserify@1.1.2**
      * Licenses: MIT
      * Repository: [https://github.com/substack/vm-browserify](https://github.com/substack/vm-browserify)
-1. **watchpack-chokidar2@2.0.1**
+1. **watchpack-chokidar2@2.0.0**
      * Licenses: MIT
      * Repository: [https://github.com/webpack/watchpack](https://github.com/webpack/watchpack)
-1. **watchpack@1.7.5**
+1. **watchpack@1.7.4**
      * Licenses: MIT
      * Repository: [https://github.com/webpack/watchpack](https://github.com/webpack/watchpack)
 1. **webpack-cli@4.2.0**
@@ -2797,17 +2750,17 @@ This report was generated on **Mon Nov 23 17:08:56 EET 2020** using [Gradle-Lice
 1. **yargs@13.3.2**
      * Licenses: MIT
      * Repository: [https://github.com/yargs/yargs](https://github.com/yargs/yargs)
-1. **yargs@15.3.1**
+1. **yargs@15.4.1**
      * Licenses: MIT
      * Repository: [https://github.com/yargs/yargs](https://github.com/yargs/yargs)
 
 
-This report was generated on **Mon Nov 23 2020 17:08:57 GMT+0200 (Eastern European Standard Time)** using [NPM License Checker](https://github.com/davglass/license-checker) library.
+This report was generated on **Mon Dec 07 2020 12:18:24 GMT+0200 (Eastern European Standard Time)** using [NPM License Checker](https://github.com/davglass/license-checker) library.
 
 
 
     
-# Dependencies of `io.spine.gcloud:spine-firebase-web:1.6.15`
+# Dependencies of `io.spine.gcloud:spine-firebase-web:1.6.16`
 
 ## Runtime
 1. **Group:** com.fasterxml.jackson.core **Name:** jackson-annotations **Version:** 2.9.10
@@ -2908,9 +2861,6 @@ This report was generated on **Mon Nov 23 2020 17:08:57 GMT+0200 (Eastern Europe
 1. **Group:** com.google.errorprone **Name:** error_prone_annotations **Version:** 2.4.0
      * **POM License: Apache 2.0** - [http://www.apache.org/licenses/LICENSE-2.0.txt](http://www.apache.org/licenses/LICENSE-2.0.txt)
 
-1. **Group:** com.google.errorprone **Name:** error_prone_type_annotations **Version:** 2.4.0
-     * **POM License: Apache 2.0** - [http://www.apache.org/licenses/LICENSE-2.0.txt](http://www.apache.org/licenses/LICENSE-2.0.txt)
-
 1. **Group:** com.google.firebase **Name:** firebase-admin **Version:** 6.12.2
      * **POM Project URL:** [https://firebase.google.com/](https://firebase.google.com/)
      * **POM License: Apache License, Version 2.0** - [https://www.apache.org/licenses/LICENSE-2.0.txt](https://www.apache.org/licenses/LICENSE-2.0.txt)
@@ -3433,12 +3383,6 @@ This report was generated on **Mon Nov 23 2020 17:08:57 GMT+0200 (Eastern Europe
      * **POM Project URL:** [https://github.com/trustin/os-maven-plugin/](https://github.com/trustin/os-maven-plugin/)
      * **POM License: Apache License, Version 2.0** - [http://www.apache.org/licenses/LICENSE-2.0](http://www.apache.org/licenses/LICENSE-2.0)
 
-1. **Group:** net.bytebuddy **Name:** byte-buddy **Version:** 1.7.9
-     * **POM License: The Apache Software License, Version 2.0** - [http://www.apache.org/licenses/LICENSE-2.0.txt](http://www.apache.org/licenses/LICENSE-2.0.txt)
-
-1. **Group:** net.bytebuddy **Name:** byte-buddy-agent **Version:** 1.7.9
-     * **POM License: The Apache Software License, Version 2.0** - [http://www.apache.org/licenses/LICENSE-2.0.txt](http://www.apache.org/licenses/LICENSE-2.0.txt)
-
 1. **Group:** net.java.dev.javacc **Name:** javacc **Version:** 5.0
      * **POM Project URL:** [https://javacc.dev.java.net/](https://javacc.dev.java.net/)
      * **POM License: Berkeley Software Distribution (BSD) License** - [http://www.opensource.org/licenses/bsd-license.html](http://www.opensource.org/licenses/bsd-license.html)
@@ -3493,9 +3437,6 @@ This report was generated on **Mon Nov 23 2020 17:08:57 GMT+0200 (Eastern Europe
      * **POM License: MIT license** - [http://www.opensource.org/licenses/mit-license.php](http://www.opensource.org/licenses/mit-license.php)
      * **POM License: The Apache Software License, Version 2.0** - [http://www.apache.org/licenses/LICENSE-2.0.txt](http://www.apache.org/licenses/LICENSE-2.0.txt)
 
-1. **Group:** org.hamcrest **Name:** hamcrest-all **Version:** 1.3
-     * **POM License: New BSD License** - [http://www.opensource.org/licenses/bsd-license.php](http://www.opensource.org/licenses/bsd-license.php)
-
 1. **Group:** org.hamcrest **Name:** hamcrest-core **Version:** 1.3
      * **POM License: New BSD License** - [http://www.opensource.org/licenses/bsd-license.php](http://www.opensource.org/licenses/bsd-license.php)
 
@@ -3532,14 +3473,6 @@ This report was generated on **Mon Nov 23 2020 17:08:57 GMT+0200 (Eastern Europe
      * **POM Project URL:** [https://junit.org/junit5/](https://junit.org/junit5/)
      * **POM License: Eclipse Public License v2.0** - [https://www.eclipse.org/legal/epl-v20.html](https://www.eclipse.org/legal/epl-v20.html)
 
-1. **Group:** org.mockito **Name:** mockito-core **Version:** 2.12.0
-     * **POM Project URL:** [https://github.com/mockito/mockito](https://github.com/mockito/mockito)
-     * **POM License: The MIT License** - [https://github.com/mockito/mockito/blob/master/LICENSE](https://github.com/mockito/mockito/blob/master/LICENSE)
-
-1. **Group:** org.objenesis **Name:** objenesis **Version:** 2.6
-     * **POM Project URL:** [http://objenesis.org](http://objenesis.org)
-     * **POM License: Apache 2** - [http://www.apache.org/licenses/LICENSE-2.0.txt](http://www.apache.org/licenses/LICENSE-2.0.txt)
-
 1. **Group:** org.opentest4j **Name:** opentest4j **Version:** 1.2.0
      * **Manifest License:** The Apache License, Version 2.0 (Not packaged)
      * **POM Project URL:** [https://github.com/ota4j-team/opentest4j](https://github.com/ota4j-team/opentest4j)
@@ -3614,12 +3547,12 @@ This report was generated on **Mon Nov 23 2020 17:08:57 GMT+0200 (Eastern Europe
  The dependencies distributed under several licenses, are used according their commercial-use-friendly license.
 
 
-This report was generated on **Mon Nov 23 17:09:07 EET 2020** using [Gradle-License-Report plugin](https://github.com/jk1/Gradle-License-Report) by Evgeny Naumenko, licensed under [Apache 2.0 License](https://github.com/jk1/Gradle-License-Report/blob/master/LICENSE).
+This report was generated on **Mon Dec 07 12:13:51 EET 2020** using [Gradle-License-Report plugin](https://github.com/jk1/Gradle-License-Report) by Evgeny Naumenko, licensed under [Apache 2.0 License](https://github.com/jk1/Gradle-License-Report/blob/master/LICENSE).
 
 
 
     
-# Dependencies of `io.spine:spine-js-tests:1.6.15`
+# Dependencies of `io.spine:spine-js-tests:1.6.16`
 
 ## Runtime
 1. **Group:** com.google.code.findbugs **Name:** jsr305 **Version:** 3.0.2
@@ -3629,9 +3562,6 @@ This report was generated on **Mon Nov 23 17:09:07 EET 2020** using [Gradle-Lice
 1. **Group:** com.google.errorprone **Name:** error_prone_annotations **Version:** 2.4.0
      * **POM License: Apache 2.0** - [http://www.apache.org/licenses/LICENSE-2.0.txt](http://www.apache.org/licenses/LICENSE-2.0.txt)
 
-1. **Group:** com.google.errorprone **Name:** error_prone_type_annotations **Version:** 2.4.0
-     * **POM License: Apache 2.0** - [http://www.apache.org/licenses/LICENSE-2.0.txt](http://www.apache.org/licenses/LICENSE-2.0.txt)
-
 1. **Group:** com.google.guava **Name:** failureaccess **Version:** 1.0.1
      * **Manifest Project URL:** [https://github.com/google/guava/](https://github.com/google/guava/)
      * **POM License: The Apache Software License, Version 2.0** - [http://www.apache.org/licenses/LICENSE-2.0.txt](http://www.apache.org/licenses/LICENSE-2.0.txt)
@@ -3853,12 +3783,6 @@ This report was generated on **Mon Nov 23 17:09:07 EET 2020** using [Gradle-Lice
      * **POM Project URL:** [http://junit.org](http://junit.org)
      * **POM License: Eclipse Public License 1.0** - [http://www.eclipse.org/legal/epl-v10.html](http://www.eclipse.org/legal/epl-v10.html)
 
-1. **Group:** net.bytebuddy **Name:** byte-buddy **Version:** 1.7.9
-     * **POM License: The Apache Software License, Version 2.0** - [http://www.apache.org/licenses/LICENSE-2.0.txt](http://www.apache.org/licenses/LICENSE-2.0.txt)
-
-1. **Group:** net.bytebuddy **Name:** byte-buddy-agent **Version:** 1.7.9
-     * **POM License: The Apache Software License, Version 2.0** - [http://www.apache.org/licenses/LICENSE-2.0.txt](http://www.apache.org/licenses/LICENSE-2.0.txt)
-
 1. **Group:** net.java.dev.javacc **Name:** javacc **Version:** 5.0
      * **POM Project URL:** [https://javacc.dev.java.net/](https://javacc.dev.java.net/)
      * **POM License: Berkeley Software Distribution (BSD) License** - [http://www.opensource.org/licenses/bsd-license.html](http://www.opensource.org/licenses/bsd-license.html)
@@ -3913,9 +3837,6 @@ This report was generated on **Mon Nov 23 17:09:07 EET 2020** using [Gradle-Lice
      * **POM License: MIT license** - [http://www.opensource.org/licenses/mit-license.php](http://www.opensource.org/licenses/mit-license.php)
      * **POM License: The Apache Software License, Version 2.0** - [http://www.apache.org/licenses/LICENSE-2.0.txt](http://www.apache.org/licenses/LICENSE-2.0.txt)
 
-1. **Group:** org.hamcrest **Name:** hamcrest-all **Version:** 1.3
-     * **POM License: New BSD License** - [http://www.opensource.org/licenses/bsd-license.php](http://www.opensource.org/licenses/bsd-license.php)
-
 1. **Group:** org.hamcrest **Name:** hamcrest-core **Version:** 1.3
      * **POM License: New BSD License** - [http://www.opensource.org/licenses/bsd-license.php](http://www.opensource.org/licenses/bsd-license.php)
 
@@ -3952,14 +3873,6 @@ This report was generated on **Mon Nov 23 17:09:07 EET 2020** using [Gradle-Lice
      * **POM Project URL:** [https://junit.org/junit5/](https://junit.org/junit5/)
      * **POM License: Eclipse Public License v2.0** - [https://www.eclipse.org/legal/epl-v20.html](https://www.eclipse.org/legal/epl-v20.html)
 
-1. **Group:** org.mockito **Name:** mockito-core **Version:** 2.12.0
-     * **POM Project URL:** [https://github.com/mockito/mockito](https://github.com/mockito/mockito)
-     * **POM License: The MIT License** - [https://github.com/mockito/mockito/blob/master/LICENSE](https://github.com/mockito/mockito/blob/master/LICENSE)
-
-1. **Group:** org.objenesis **Name:** objenesis **Version:** 2.6
-     * **POM Project URL:** [http://objenesis.org](http://objenesis.org)
-     * **POM License: Apache 2** - [http://www.apache.org/licenses/LICENSE-2.0.txt](http://www.apache.org/licenses/LICENSE-2.0.txt)
-
 1. **Group:** org.opentest4j **Name:** opentest4j **Version:** 1.2.0
      * **Manifest License:** The Apache License, Version 2.0 (Not packaged)
      * **POM Project URL:** [https://github.com/ota4j-team/opentest4j](https://github.com/ota4j-team/opentest4j)
@@ -4029,12 +3942,12 @@ This report was generated on **Mon Nov 23 17:09:07 EET 2020** using [Gradle-Lice
  The dependencies distributed under several licenses, are used according their commercial-use-friendly license.
 
 
-This report was generated on **Mon Nov 23 17:09:22 EET 2020** using [Gradle-License-Report plugin](https://github.com/jk1/Gradle-License-Report) by Evgeny Naumenko, licensed under [Apache 2.0 License](https://github.com/jk1/Gradle-License-Report/blob/master/LICENSE).
+This report was generated on **Mon Dec 07 12:14:00 EET 2020** using [Gradle-License-Report plugin](https://github.com/jk1/Gradle-License-Report) by Evgeny Naumenko, licensed under [Apache 2.0 License](https://github.com/jk1/Gradle-License-Report/blob/master/LICENSE).
 
 
 
     
-# Dependencies of `io.spine:spine-test-app:1.6.15`
+# Dependencies of `io.spine:spine-test-app:1.6.16`
 
 ## Runtime
 1. **Group:** com.fasterxml.jackson.core **Name:** jackson-annotations **Version:** 2.9.10
@@ -4135,9 +4048,6 @@ This report was generated on **Mon Nov 23 17:09:22 EET 2020** using [Gradle-Lice
 1. **Group:** com.google.errorprone **Name:** error_prone_annotations **Version:** 2.4.0
      * **POM License: Apache 2.0** - [http://www.apache.org/licenses/LICENSE-2.0.txt](http://www.apache.org/licenses/LICENSE-2.0.txt)
 
-1. **Group:** com.google.errorprone **Name:** error_prone_type_annotations **Version:** 2.4.0
-     * **POM License: Apache 2.0** - [http://www.apache.org/licenses/LICENSE-2.0.txt](http://www.apache.org/licenses/LICENSE-2.0.txt)
-
 1. **Group:** com.google.firebase **Name:** firebase-admin **Version:** 6.12.2
      * **POM Project URL:** [https://firebase.google.com/](https://firebase.google.com/)
      * **POM License: Apache License, Version 2.0** - [https://www.apache.org/licenses/LICENSE-2.0.txt](https://www.apache.org/licenses/LICENSE-2.0.txt)
@@ -4724,12 +4634,6 @@ This report was generated on **Mon Nov 23 17:09:22 EET 2020** using [Gradle-Lice
      * **POM Project URL:** [https://github.com/trustin/os-maven-plugin/](https://github.com/trustin/os-maven-plugin/)
      * **POM License: Apache License, Version 2.0** - [http://www.apache.org/licenses/LICENSE-2.0](http://www.apache.org/licenses/LICENSE-2.0)
 
-1. **Group:** net.bytebuddy **Name:** byte-buddy **Version:** 1.7.9
-     * **POM License: The Apache Software License, Version 2.0** - [http://www.apache.org/licenses/LICENSE-2.0.txt](http://www.apache.org/licenses/LICENSE-2.0.txt)
-
-1. **Group:** net.bytebuddy **Name:** byte-buddy-agent **Version:** 1.7.9
-     * **POM License: The Apache Software License, Version 2.0** - [http://www.apache.org/licenses/LICENSE-2.0.txt](http://www.apache.org/licenses/LICENSE-2.0.txt)
-
 1. **Group:** net.java.dev.javacc **Name:** javacc **Version:** 5.0
      * **POM Project URL:** [https://javacc.dev.java.net/](https://javacc.dev.java.net/)
      * **POM License: Berkeley Software Distribution (BSD) License** - [http://www.opensource.org/licenses/bsd-license.html](http://www.opensource.org/licenses/bsd-license.html)
@@ -5416,9 +5320,6 @@ This report was generated on **Mon Nov 23 17:09:22 EET 2020** using [Gradle-Lice
      * **POM Project URL:** [https://github.com/gretty-gradle-plugin/gretty](https://github.com/gretty-gradle-plugin/gretty)
      * **POM License: MIT** - [https://raw.github.com/gretty-gradle-plugin/gretty/master/LICENSE](https://raw.github.com/gretty-gradle-plugin/gretty/master/LICENSE)
 
-1. **Group:** org.hamcrest **Name:** hamcrest-all **Version:** 1.3
-     * **POM License: New BSD License** - [http://www.opensource.org/licenses/bsd-license.php](http://www.opensource.org/licenses/bsd-license.php)
-
 1. **Group:** org.hamcrest **Name:** hamcrest-core **Version:** 1.3
      * **POM License: New BSD License** - [http://www.opensource.org/licenses/bsd-license.php](http://www.opensource.org/licenses/bsd-license.php)
 
@@ -5455,10 +5356,6 @@ This report was generated on **Mon Nov 23 17:09:22 EET 2020** using [Gradle-Lice
      * **POM Project URL:** [https://junit.org/junit5/](https://junit.org/junit5/)
      * **POM License: Eclipse Public License v2.0** - [https://www.eclipse.org/legal/epl-v20.html](https://www.eclipse.org/legal/epl-v20.html)
 
-1. **Group:** org.mockito **Name:** mockito-core **Version:** 2.12.0
-     * **POM Project URL:** [https://github.com/mockito/mockito](https://github.com/mockito/mockito)
-     * **POM License: The MIT License** - [https://github.com/mockito/mockito/blob/master/LICENSE](https://github.com/mockito/mockito/blob/master/LICENSE)
-
 1. **Group:** org.mortbay.jasper **Name:** apache-el **Version:** 8.0.33
      * **Manifest Project URL:** [http://webtide.com](http://webtide.com)
      * **POM License: Apache License Version 2.0** - [http://www.apache.org/licenses/LICENSE-2.0](http://www.apache.org/licenses/LICENSE-2.0)
@@ -5477,10 +5374,6 @@ This report was generated on **Mon Nov 23 17:09:22 EET 2020** using [Gradle-Lice
 1. **Group:** org.mortbay.jasper **Name:** apache-jsp **Version:** 8.5.40
      * **POM License: Apache License Version 2.0** - [http://www.apache.org/licenses/LICENSE-2.0](http://www.apache.org/licenses/LICENSE-2.0)
 
-1. **Group:** org.objenesis **Name:** objenesis **Version:** 2.6
-     * **POM Project URL:** [http://objenesis.org](http://objenesis.org)
-     * **POM License: Apache 2** - [http://www.apache.org/licenses/LICENSE-2.0.txt](http://www.apache.org/licenses/LICENSE-2.0.txt)
-
 1. **Group:** org.opentest4j **Name:** opentest4j **Version:** 1.2.0
      * **Manifest License:** The Apache License, Version 2.0 (Not packaged)
      * **POM Project URL:** [https://github.com/ota4j-team/opentest4j](https://github.com/ota4j-team/opentest4j)
@@ -5628,12 +5521,12 @@ This report was generated on **Mon Nov 23 17:09:22 EET 2020** using [Gradle-Lice
  The dependencies distributed under several licenses, are used according their commercial-use-friendly license.
 
 
-This report was generated on **Mon Nov 23 17:10:40 EET 2020** using [Gradle-License-Report plugin](https://github.com/jk1/Gradle-License-Report) by Evgeny Naumenko, licensed under [Apache 2.0 License](https://github.com/jk1/Gradle-License-Report/blob/master/LICENSE).
+This report was generated on **Mon Dec 07 12:14:05 EET 2020** using [Gradle-License-Report plugin](https://github.com/jk1/Gradle-License-Report) by Evgeny Naumenko, licensed under [Apache 2.0 License](https://github.com/jk1/Gradle-License-Report/blob/master/LICENSE).
 
 
 
     
-# Dependencies of `io.spine:spine-testutil-web:1.6.15`
+# Dependencies of `io.spine:spine-testutil-web:1.6.16`
 
 ## Runtime
 1. **Group:** com.google.android **Name:** annotations **Version:** 4.1.1.4
@@ -5654,9 +5547,6 @@ This report was generated on **Mon Nov 23 17:10:40 EET 2020** using [Gradle-Lice
 1. **Group:** com.google.errorprone **Name:** error_prone_annotations **Version:** 2.4.0
      * **POM License: Apache 2.0** - [http://www.apache.org/licenses/LICENSE-2.0.txt](http://www.apache.org/licenses/LICENSE-2.0.txt)
 
-1. **Group:** com.google.errorprone **Name:** error_prone_type_annotations **Version:** 2.4.0
-     * **POM License: Apache 2.0** - [http://www.apache.org/licenses/LICENSE-2.0.txt](http://www.apache.org/licenses/LICENSE-2.0.txt)
-
 1. **Group:** com.google.flogger **Name:** flogger **Version:** 0.5.1
      * **POM Project URL:** [https://github.com/google/flogger](https://github.com/google/flogger)
      * **POM License: Apache 2.0** - [https://www.apache.org/licenses/LICENSE-2.0.txt](https://www.apache.org/licenses/LICENSE-2.0.txt)
@@ -5944,12 +5834,6 @@ This report was generated on **Mon Nov 23 17:10:40 EET 2020** using [Gradle-Lice
      * **POM Project URL:** [http://junit.org](http://junit.org)
      * **POM License: Eclipse Public License 1.0** - [http://www.eclipse.org/legal/epl-v10.html](http://www.eclipse.org/legal/epl-v10.html)
 
-1. **Group:** net.bytebuddy **Name:** byte-buddy **Version:** 1.7.9
-     * **POM License: The Apache Software License, Version 2.0** - [http://www.apache.org/licenses/LICENSE-2.0.txt](http://www.apache.org/licenses/LICENSE-2.0.txt)
-
-1. **Group:** net.bytebuddy **Name:** byte-buddy-agent **Version:** 1.7.9
-     * **POM License: The Apache Software License, Version 2.0** - [http://www.apache.org/licenses/LICENSE-2.0.txt](http://www.apache.org/licenses/LICENSE-2.0.txt)
-
 1. **Group:** net.java.dev.javacc **Name:** javacc **Version:** 5.0
      * **POM Project URL:** [https://javacc.dev.java.net/](https://javacc.dev.java.net/)
      * **POM License: Berkeley Software Distribution (BSD) License** - [http://www.opensource.org/licenses/bsd-license.html](http://www.opensource.org/licenses/bsd-license.html)
@@ -6004,9 +5888,6 @@ This report was generated on **Mon Nov 23 17:10:40 EET 2020** using [Gradle-Lice
      * **POM License: MIT license** - [http://www.opensource.org/licenses/mit-license.php](http://www.opensource.org/licenses/mit-license.php)
      * **POM License: The Apache Software License, Version 2.0** - [http://www.apache.org/licenses/LICENSE-2.0.txt](http://www.apache.org/licenses/LICENSE-2.0.txt)
 
-1. **Group:** org.hamcrest **Name:** hamcrest-all **Version:** 1.3
-     * **POM License: New BSD License** - [http://www.opensource.org/licenses/bsd-license.php](http://www.opensource.org/licenses/bsd-license.php)
-
 1. **Group:** org.hamcrest **Name:** hamcrest-core **Version:** 1.3
      * **POM License: New BSD License** - [http://www.opensource.org/licenses/bsd-license.php](http://www.opensource.org/licenses/bsd-license.php)
 
@@ -6043,14 +5924,6 @@ This report was generated on **Mon Nov 23 17:10:40 EET 2020** using [Gradle-Lice
      * **POM Project URL:** [https://junit.org/junit5/](https://junit.org/junit5/)
      * **POM License: Eclipse Public License v2.0** - [https://www.eclipse.org/legal/epl-v20.html](https://www.eclipse.org/legal/epl-v20.html)
 
-1. **Group:** org.mockito **Name:** mockito-core **Version:** 2.12.0
-     * **POM Project URL:** [https://github.com/mockito/mockito](https://github.com/mockito/mockito)
-     * **POM License: The MIT License** - [https://github.com/mockito/mockito/blob/master/LICENSE](https://github.com/mockito/mockito/blob/master/LICENSE)
-
-1. **Group:** org.objenesis **Name:** objenesis **Version:** 2.6
-     * **POM Project URL:** [http://objenesis.org](http://objenesis.org)
-     * **POM License: Apache 2** - [http://www.apache.org/licenses/LICENSE-2.0.txt](http://www.apache.org/licenses/LICENSE-2.0.txt)
-
 1. **Group:** org.opentest4j **Name:** opentest4j **Version:** 1.2.0
      * **Manifest License:** The Apache License, Version 2.0 (Not packaged)
      * **POM Project URL:** [https://github.com/ota4j-team/opentest4j](https://github.com/ota4j-team/opentest4j)
@@ -6112,12 +5985,12 @@ This report was generated on **Mon Nov 23 17:10:40 EET 2020** using [Gradle-Lice
  The dependencies distributed under several licenses, are used according their commercial-use-friendly license.
 
 
-This report was generated on **Mon Nov 23 17:10:40 EET 2020** using [Gradle-License-Report plugin](https://github.com/jk1/Gradle-License-Report) by Evgeny Naumenko, licensed under [Apache 2.0 License](https://github.com/jk1/Gradle-License-Report/blob/master/LICENSE).
+This report was generated on **Mon Dec 07 12:14:05 EET 2020** using [Gradle-License-Report plugin](https://github.com/jk1/Gradle-License-Report) by Evgeny Naumenko, licensed under [Apache 2.0 License](https://github.com/jk1/Gradle-License-Report/blob/master/LICENSE).
 
 
 
     
-# Dependencies of `io.spine:spine-web:1.6.15`
+# Dependencies of `io.spine:spine-web:1.6.16`
 
 ## Runtime
 1. **Group:** com.google.android **Name:** annotations **Version:** 4.1.1.4
@@ -6138,9 +6011,6 @@ This report was generated on **Mon Nov 23 17:10:40 EET 2020** using [Gradle-Lice
 1. **Group:** com.google.errorprone **Name:** error_prone_annotations **Version:** 2.4.0
      * **POM License: Apache 2.0** - [http://www.apache.org/licenses/LICENSE-2.0.txt](http://www.apache.org/licenses/LICENSE-2.0.txt)
 
-1. **Group:** com.google.errorprone **Name:** error_prone_type_annotations **Version:** 2.4.0
-     * **POM License: Apache 2.0** - [http://www.apache.org/licenses/LICENSE-2.0.txt](http://www.apache.org/licenses/LICENSE-2.0.txt)
-
 1. **Group:** com.google.flogger **Name:** flogger **Version:** 0.5.1
      * **POM Project URL:** [https://github.com/google/flogger](https://github.com/google/flogger)
      * **POM License: Apache 2.0** - [https://www.apache.org/licenses/LICENSE-2.0.txt](https://www.apache.org/licenses/LICENSE-2.0.txt)
@@ -6467,12 +6337,6 @@ This report was generated on **Mon Nov 23 17:10:40 EET 2020** using [Gradle-Lice
      * **POM Project URL:** [https://github.com/trustin/os-maven-plugin/](https://github.com/trustin/os-maven-plugin/)
      * **POM License: Apache License, Version 2.0** - [http://www.apache.org/licenses/LICENSE-2.0](http://www.apache.org/licenses/LICENSE-2.0)
 
-1. **Group:** net.bytebuddy **Name:** byte-buddy **Version:** 1.7.9
-     * **POM License: The Apache Software License, Version 2.0** - [http://www.apache.org/licenses/LICENSE-2.0.txt](http://www.apache.org/licenses/LICENSE-2.0.txt)
-
-1. **Group:** net.bytebuddy **Name:** byte-buddy-agent **Version:** 1.7.9
-     * **POM License: The Apache Software License, Version 2.0** - [http://www.apache.org/licenses/LICENSE-2.0.txt](http://www.apache.org/licenses/LICENSE-2.0.txt)
-
 1. **Group:** net.java.dev.javacc **Name:** javacc **Version:** 5.0
      * **POM Project URL:** [https://javacc.dev.java.net/](https://javacc.dev.java.net/)
      * **POM License: Berkeley Software Distribution (BSD) License** - [http://www.opensource.org/licenses/bsd-license.html](http://www.opensource.org/licenses/bsd-license.html)
@@ -6527,9 +6391,6 @@ This report was generated on **Mon Nov 23 17:10:40 EET 2020** using [Gradle-Lice
      * **POM License: MIT license** - [http://www.opensource.org/licenses/mit-license.php](http://www.opensource.org/licenses/mit-license.php)
      * **POM License: The Apache Software License, Version 2.0** - [http://www.apache.org/licenses/LICENSE-2.0.txt](http://www.apache.org/licenses/LICENSE-2.0.txt)
 
-1. **Group:** org.hamcrest **Name:** hamcrest-all **Version:** 1.3
-     * **POM License: New BSD License** - [http://www.opensource.org/licenses/bsd-license.php](http://www.opensource.org/licenses/bsd-license.php)
-
 1. **Group:** org.hamcrest **Name:** hamcrest-core **Version:** 1.3
      * **POM License: New BSD License** - [http://www.opensource.org/licenses/bsd-license.php](http://www.opensource.org/licenses/bsd-license.php)
 
@@ -6566,14 +6427,6 @@ This report was generated on **Mon Nov 23 17:10:40 EET 2020** using [Gradle-Lice
      * **POM Project URL:** [https://junit.org/junit5/](https://junit.org/junit5/)
      * **POM License: Eclipse Public License v2.0** - [https://www.eclipse.org/legal/epl-v20.html](https://www.eclipse.org/legal/epl-v20.html)
 
-1. **Group:** org.mockito **Name:** mockito-core **Version:** 2.12.0
-     * **POM Project URL:** [https://github.com/mockito/mockito](https://github.com/mockito/mockito)
-     * **POM License: The MIT License** - [https://github.com/mockito/mockito/blob/master/LICENSE](https://github.com/mockito/mockito/blob/master/LICENSE)
-
-1. **Group:** org.objenesis **Name:** objenesis **Version:** 2.6
-     * **POM Project URL:** [http://objenesis.org](http://objenesis.org)
-     * **POM License: Apache 2** - [http://www.apache.org/licenses/LICENSE-2.0.txt](http://www.apache.org/licenses/LICENSE-2.0.txt)
-
 1. **Group:** org.opentest4j **Name:** opentest4j **Version:** 1.2.0
      * **Manifest License:** The Apache License, Version 2.0 (Not packaged)
      * **POM Project URL:** [https://github.com/ota4j-team/opentest4j](https://github.com/ota4j-team/opentest4j)
@@ -6635,4 +6488,4 @@ This report was generated on **Mon Nov 23 17:10:40 EET 2020** using [Gradle-Lice
  The dependencies distributed under several licenses, are used according their commercial-use-friendly license.
 
 
-This report was generated on **Mon Nov 23 17:10:42 EET 2020** using [Gradle-License-Report plugin](https://github.com/jk1/Gradle-License-Report) by Evgeny Naumenko, licensed under [Apache 2.0 License](https://github.com/jk1/Gradle-License-Report/blob/master/LICENSE).
\ No newline at end of file
+This report was generated on **Mon Dec 07 12:14:08 EET 2020** using [Gradle-License-Report plugin](https://github.com/jk1/Gradle-License-Report) by Evgeny Naumenko, licensed under [Apache 2.0 License](https://github.com/jk1/Gradle-License-Report/blob/master/LICENSE).
\ No newline at end of file
diff --git a/pom.xml b/pom.xml
index 46524fd98..3236299c6 100644
--- a/pom.xml
+++ b/pom.xml
@@ -12,7 +12,7 @@ all modules and does not describe the project structure per-subproject.
 
 <groupId>io.spine</groupId>
 <artifactId>spine-web</artifactId>
-<version>1.6.15</version>
+<version>1.6.16</version>
 
 <inceptionYear>2015</inceptionYear>
 
@@ -31,18 +31,6 @@ all modules and does not describe the project structure per-subproject.
     <version>2.9.10.5</version>
     <scope>compile</scope>
   </dependency>
-  <dependency>
-    <groupId>com.google.errorprone</groupId>
-    <artifactId>error_prone_annotations</artifactId>
-    <version>2.4.0</version>
-    <scope>compile</scope>
-  </dependency>
-  <dependency>
-    <groupId>com.google.errorprone</groupId>
-    <artifactId>error_prone_type_annotations</artifactId>
-    <version>2.4.0</version>
-    <scope>compile</scope>
-  </dependency>
   <dependency>
     <groupId>com.google.firebase</groupId>
     <artifactId>firebase-admin</artifactId>
@@ -70,13 +58,7 @@ all modules and does not describe the project structure per-subproject.
   <dependency>
     <groupId>io.spine</groupId>
     <artifactId>spine-server</artifactId>
-    <version>1.6.15</version>
-    <scope>compile</scope>
-  </dependency>
-  <dependency>
-    <groupId>org.checkerframework</groupId>
-    <artifactId>checker-qual</artifactId>
-    <version>3.7.1</version>
+    <version>1.6.18</version>
     <scope>compile</scope>
   </dependency>
   <dependency>
@@ -91,16 +73,34 @@ all modules and does not describe the project structure per-subproject.
     <version>30.0-jre</version>
     <scope>test</scope>
   </dependency>
+  <dependency>
+    <groupId>com.google.truth</groupId>
+    <artifactId>truth</artifactId>
+    <version>1.1</version>
+    <scope>test</scope>
+  </dependency>
+  <dependency>
+    <groupId>com.google.truth.extensions</groupId>
+    <artifactId>truth-java8-extension</artifactId>
+    <version>1.1</version>
+    <scope>test</scope>
+  </dependency>
+  <dependency>
+    <groupId>com.google.truth.extensions</groupId>
+    <artifactId>truth-proto-extension</artifactId>
+    <version>1.1</version>
+    <scope>test</scope>
+  </dependency>
   <dependency>
     <groupId>io.spine</groupId>
     <artifactId>spine-testutil-client</artifactId>
-    <version>1.6.15</version>
+    <version>1.6.18</version>
     <scope>test</scope>
   </dependency>
   <dependency>
     <groupId>io.spine.tools</groupId>
     <artifactId>spine-mute-logging</artifactId>
-    <version>1.6.13</version>
+    <version>1.6.16</version>
     <scope>test</scope>
   </dependency>
   <dependency>
@@ -109,12 +109,6 @@ all modules and does not describe the project structure per-subproject.
     <version>1.1.0</version>
     <scope>test</scope>
   </dependency>
-  <dependency>
-    <groupId>org.hamcrest</groupId>
-    <artifactId>hamcrest-all</artifactId>
-    <version>1.3</version>
-    <scope>test</scope>
-  </dependency>
   <dependency>
     <groupId>org.junit.jupiter</groupId>
     <artifactId>junit-jupiter-api</artifactId>
@@ -133,12 +127,6 @@ all modules and does not describe the project structure per-subproject.
     <version>5.7.0</version>
     <scope>test</scope>
   </dependency>
-  <dependency>
-    <groupId>org.mockito</groupId>
-    <artifactId>mockito-core</artifactId>
-    <version>2.12.0</version>
-    <scope>test</scope>
-  </dependency>
   <dependency>
     <groupId>com.google.errorprone</groupId>
     <artifactId>error_prone_core</artifactId>
@@ -162,22 +150,17 @@ all modules and does not describe the project structure per-subproject.
   <dependency>
     <groupId>io.spine</groupId>
     <artifactId>spine-client</artifactId>
-    <version>1.6.15</version>
-  </dependency>
-  <dependency>
-    <groupId>io.spine.tools</groupId>
-    <artifactId>spine-errorprone-checks</artifactId>
-    <version>1.6.13</version>
+    <version>1.6.18</version>
   </dependency>
   <dependency>
     <groupId>io.spine.tools</groupId>
     <artifactId>spine-javadoc-filter</artifactId>
-    <version>1.6.13</version>
+    <version>1.6.16</version>
   </dependency>
   <dependency>
     <groupId>io.spine.tools</groupId>
     <artifactId>spine-protoc-plugin</artifactId>
-    <version>1.6.13</version>
+    <version>1.6.16</version>
   </dependency>
   <dependency>
     <groupId>javax.servlet</groupId>

From c3eb6a662da914e66e585c7da743d2bd0b593eec Mon Sep 17 00:00:00 2001
From: Yuri Sergiichuk <yuri.sergiichuk@teamdev.com>
Date: Mon, 7 Dec 2020 12:24:45 +0200
Subject: [PATCH 21/41] Expose `web` to the users.

---
 testutil-web/build.gradle.kts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/testutil-web/build.gradle.kts b/testutil-web/build.gradle.kts
index 3cd25f3ee..bb03c2b26 100644
--- a/testutil-web/build.gradle.kts
+++ b/testutil-web/build.gradle.kts
@@ -19,5 +19,5 @@
  */
 
 dependencies {
-    implementation(project(":web"))
+    api(project(":web"))
 }

From f57813e9a00049c88656cd8b74f8bfeb5db6aba7 Mon Sep 17 00:00:00 2001
From: Yuri Sergiichuk <yuri.sergiichuk@teamdev.com>
Date: Mon, 7 Dec 2020 12:27:15 +0200
Subject: [PATCH 22/41] Drop `InMemFirebaseClient` in favor of
 `MemoizedFirebase`.

---
 .../FirebaseSubscriptionBridgeTest.java       |  5 +-
 .../given/InMemFirebaseClient.java            | 60 -------------------
 .../subscription/given/package-info.java      | 27 ---------
 3 files changed, 1 insertion(+), 91 deletions(-)
 delete mode 100644 firebase-web/src/test/java/io/spine/web/firebase/subscription/given/InMemFirebaseClient.java
 delete mode 100644 firebase-web/src/test/java/io/spine/web/firebase/subscription/given/package-info.java

diff --git a/firebase-web/src/test/java/io/spine/web/firebase/subscription/FirebaseSubscriptionBridgeTest.java b/firebase-web/src/test/java/io/spine/web/firebase/subscription/FirebaseSubscriptionBridgeTest.java
index e2a1975ae..ecc976c87 100644
--- a/firebase-web/src/test/java/io/spine/web/firebase/subscription/FirebaseSubscriptionBridgeTest.java
+++ b/firebase-web/src/test/java/io/spine/web/firebase/subscription/FirebaseSubscriptionBridgeTest.java
@@ -27,9 +27,7 @@
 import io.spine.core.Response;
 import io.spine.server.BoundedContextBuilder;
 import io.spine.server.SubscriptionService;
-import io.spine.web.firebase.FirebaseClient;
 import io.spine.web.firebase.given.MemoizedFirebase;
-import io.spine.web.firebase.subscription.given.InMemFirebaseClient;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.DisplayName;
 import org.junit.jupiter.api.Test;
@@ -54,8 +52,7 @@ class FirebaseSubscriptionBridgeTest {
     @BeforeEach
     void setUp() {
         SubscriptionServiceImplBase subscriptionService = new TestSubscriptionService();
-        FirebaseClient firebaseClient = new InMemFirebaseClient();
-        bridge = newBridge(firebaseClient, subscriptionService);
+        bridge = newBridge(MemoizedFirebase.withNoLatency(), subscriptionService);
         topicFactory = topicFactory();
     }
 
diff --git a/firebase-web/src/test/java/io/spine/web/firebase/subscription/given/InMemFirebaseClient.java b/firebase-web/src/test/java/io/spine/web/firebase/subscription/given/InMemFirebaseClient.java
deleted file mode 100644
index 99b5b603c..000000000
--- a/firebase-web/src/test/java/io/spine/web/firebase/subscription/given/InMemFirebaseClient.java
+++ /dev/null
@@ -1,60 +0,0 @@
-/*
- * Copyright 2020, TeamDev. All rights reserved.
- *
- * Redistribution and use in source and/or binary forms, with or without
- * modification, must retain the above copyright notice and the following
- * disclaimer.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
-package io.spine.web.firebase.subscription.given;
-
-import com.google.firebase.database.ChildEventListener;
-import io.spine.web.firebase.FirebaseClient;
-import io.spine.web.firebase.NodePath;
-import io.spine.web.firebase.NodeValue;
-
-import java.util.HashMap;
-import java.util.Map;
-import java.util.Optional;
-
-public class InMemFirebaseClient implements FirebaseClient {
-
-    private final Map<NodePath, NodeValue> values = new HashMap<>();
-
-    @Override
-    public Optional<NodeValue> fetchNode(NodePath nodePath) {
-        return Optional.ofNullable(values.get(nodePath));
-    }
-
-    @Override
-    public void subscribeTo(NodePath nodePath, ChildEventListener listener) {
-        // Method `subscribeTo` is not supported. OK for test purposes.
-    }
-
-    @Override
-    public void create(NodePath nodePath, NodeValue value) {
-        values.put(nodePath,value);
-    }
-
-    @Override
-    public void update(NodePath nodePath, NodeValue value) {
-        values.put(nodePath,value);
-    }
-
-    @Override
-    public void delete(NodePath nodePath) {
-        values.remove(nodePath);
-    }
-}
diff --git a/firebase-web/src/test/java/io/spine/web/firebase/subscription/given/package-info.java b/firebase-web/src/test/java/io/spine/web/firebase/subscription/given/package-info.java
deleted file mode 100644
index b76e86f10..000000000
--- a/firebase-web/src/test/java/io/spine/web/firebase/subscription/given/package-info.java
+++ /dev/null
@@ -1,27 +0,0 @@
-/*
- * Copyright 2020, TeamDev. All rights reserved.
- *
- * Redistribution and use in source and/or binary forms, with or without
- * modification, must retain the above copyright notice and the following
- * disclaimer.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
-@CheckReturnValue
-@ParametersAreNonnullByDefault
-package io.spine.web.firebase.subscription.given;
-
-import com.google.errorprone.annotations.CheckReturnValue;
-
-import javax.annotation.ParametersAreNonnullByDefault;

From b93209b0c05088f485dcafc975907d4c271edc2c Mon Sep 17 00:00:00 2001
From: Yuri Sergiichuk <yuri.sergiichuk@teamdev.com>
Date: Mon, 7 Dec 2020 12:50:34 +0200
Subject: [PATCH 23/41] Improve formatting.

---
 .../spine/web/firebase/AsyncClientTest.java   | 14 ++++++----
 .../spine/web/firebase/DatabaseUrlsTest.java  |  9 ++++---
 .../firebase/FirebaseClientFactoryTest.java   |  6 +++--
 .../io/spine/web/firebase/NodePathsTest.java  |  5 +++-
 .../io/spine/web/firebase/NodeValueTest.java  | 27 +++++++++++--------
 .../FirebaseSubscriptionBridgeTestEnv.java    |  3 ++-
 .../query/FirebaseQueryBridgeTest.java        |  9 +++----
 .../rest/RemoteDatabaseClientTest.java        | 21 +++++++++------
 .../FirebaseSubscriptionBridgeTest.java       | 26 ++++++++++++------
 9 files changed, 75 insertions(+), 45 deletions(-)

diff --git a/firebase-web/src/test/java/io/spine/web/firebase/AsyncClientTest.java b/firebase-web/src/test/java/io/spine/web/firebase/AsyncClientTest.java
index 6b3eda644..b8047dbd8 100644
--- a/firebase-web/src/test/java/io/spine/web/firebase/AsyncClientTest.java
+++ b/firebase-web/src/test/java/io/spine/web/firebase/AsyncClientTest.java
@@ -34,7 +34,7 @@
 import static java.time.Duration.ofSeconds;
 import static java.util.concurrent.Executors.newSingleThreadExecutor;
 
-@DisplayName("Async Firebase client should")
+@DisplayName("`AsyncClient` should")
 class AsyncClientTest {
 
     private MemoizedFirebase delegate;
@@ -56,7 +56,8 @@ void setUp() {
     void readDirectly() {
         AsyncClient asyncClient = new AsyncClient(delegate);
         asyncClient.fetchNode(path);
-        assertThat(delegate.reads()).contains(path);
+        assertThat(delegate.reads())
+                .contains(path);
     }
 
     @Test
@@ -78,14 +79,17 @@ void executeWritesWithForkJoinPool() {
     void allowDirectExecutor() {
         AsyncClient asyncClient = new AsyncClient(delegate, directExecutor());
         asyncClient.create(path, NodeValue.empty());
-        assertThat(delegate.writes()).containsKey(path);
+        assertThat(delegate.writes())
+                .containsKey(path);
     }
 
     private void checkAsync(AsyncClient asyncClient) {
         asyncClient.update(path, NodeValue.empty());
-        assertThat(delegate.writes()).doesNotContainKey(path);
+        assertThat(delegate.writes())
+                .doesNotContainKey(path);
         Duration surefireTime = latency.plusSeconds(1);
         Uninterruptibles.sleepUninterruptibly(surefireTime);
-        assertThat(delegate.writes()).containsKey(path);
+        assertThat(delegate.writes())
+                .containsKey(path);
     }
 }
diff --git a/firebase-web/src/test/java/io/spine/web/firebase/DatabaseUrlsTest.java b/firebase-web/src/test/java/io/spine/web/firebase/DatabaseUrlsTest.java
index d86604e17..50aab5aa8 100644
--- a/firebase-web/src/test/java/io/spine/web/firebase/DatabaseUrlsTest.java
+++ b/firebase-web/src/test/java/io/spine/web/firebase/DatabaseUrlsTest.java
@@ -20,13 +20,14 @@
 
 package io.spine.web.firebase;
 
+import io.spine.net.Urls;
 import io.spine.testing.UtilityClassTest;
 import org.junit.jupiter.api.DisplayName;
 import org.junit.jupiter.api.Test;
 
-import static org.junit.jupiter.api.Assertions.assertEquals;
+import static com.google.common.truth.extensions.proto.ProtoTruth.assertThat;
 
-@DisplayName("DatabaseUrls should")
+@DisplayName("`DatabaseUrls` should")
 class DatabaseUrlsTest extends UtilityClassTest<DatabaseUrls> {
 
     private static final String VALID_URL = "https://spine-dev.appspot.com/";
@@ -39,7 +40,7 @@ class DatabaseUrlsTest extends UtilityClassTest<DatabaseUrls> {
     @DisplayName("be successfully created from valid URL")
     void acceptValidUrl() {
         DatabaseUrl url = DatabaseUrls.from(VALID_URL);
-        assertEquals(VALID_URL, url.getUrl()
-                                   .getSpec());
+        assertThat(url.getUrl())
+                .isEqualTo(Urls.create(VALID_URL));
     }
 }
diff --git a/firebase-web/src/test/java/io/spine/web/firebase/FirebaseClientFactoryTest.java b/firebase-web/src/test/java/io/spine/web/firebase/FirebaseClientFactoryTest.java
index e8830822c..9df7d95b4 100644
--- a/firebase-web/src/test/java/io/spine/web/firebase/FirebaseClientFactoryTest.java
+++ b/firebase-web/src/test/java/io/spine/web/firebase/FirebaseClientFactoryTest.java
@@ -89,7 +89,8 @@ void createForGae() {
                 .instance()
                 .configureDeployment(() -> DeploymentType.APPENGINE_CLOUD);
         FirebaseClient client = FirebaseClientFactory.remoteClient(database);
-        assertThat(client).isNotNull();
+        assertThat(client)
+                .isNotNull();
     }
 
     @Test
@@ -99,6 +100,7 @@ void createNotForGae() {
                 .instance()
                 .configureDeployment(() -> DeploymentType.STANDALONE);
         FirebaseClient client = FirebaseClientFactory.remoteClient(database);
-        assertThat(client).isNotNull();
+        assertThat(client)
+                .isNotNull();
     }
 }
diff --git a/firebase-web/src/test/java/io/spine/web/firebase/NodePathsTest.java b/firebase-web/src/test/java/io/spine/web/firebase/NodePathsTest.java
index 41974c57d..1e7c3c410 100644
--- a/firebase-web/src/test/java/io/spine/web/firebase/NodePathsTest.java
+++ b/firebase-web/src/test/java/io/spine/web/firebase/NodePathsTest.java
@@ -21,10 +21,12 @@
 package io.spine.web.firebase;
 
 import io.spine.testing.UtilityClassTest;
+import org.junit.jupiter.api.DisplayName;
 import org.junit.jupiter.api.Test;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
 
+@DisplayName("`NodePaths` should")
 class NodePathsTest extends UtilityClassTest<NodePaths> {
 
     NodePathsTest() {
@@ -32,12 +34,13 @@ class NodePathsTest extends UtilityClassTest<NodePaths> {
     }
 
     @Test
+    @DisplayName("create a valid `NodePath` message")
     void createsNodePath() {
         String testPath = "test-path";
         NodePath expected = NodePath
                 .newBuilder()
                 .setValue(testPath)
-                .build();
+                .vBuild();
         assertEquals(expected, NodePaths.of(testPath));
     }
 }
diff --git a/firebase-web/src/test/java/io/spine/web/firebase/NodeValueTest.java b/firebase-web/src/test/java/io/spine/web/firebase/NodeValueTest.java
index 4a56005f2..3f02245bc 100644
--- a/firebase-web/src/test/java/io/spine/web/firebase/NodeValueTest.java
+++ b/firebase-web/src/test/java/io/spine/web/firebase/NodeValueTest.java
@@ -20,18 +20,20 @@
 
 package io.spine.web.firebase;
 
+import com.google.common.collect.Iterators;
 import com.google.gson.JsonElement;
 import com.google.gson.JsonObject;
 import org.junit.jupiter.api.DisplayName;
 import org.junit.jupiter.api.Test;
 
 import java.util.Map;
+import java.util.Set;
 
 import static com.google.common.collect.testing.Helpers.assertEmpty;
-import static org.junit.jupiter.api.Assertions.assertEquals;
+import static com.google.common.truth.Truth.assertThat;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
-@DisplayName("NodeValue should")
+@DisplayName("`NodeValue` should")
 class NodeValueTest {
 
     private static final String KEY = "theKey";
@@ -71,14 +73,16 @@ void addChildWithKey() {
 
     private static void assertSingleChild(NodeValue value, StoredJson childValue) {
         JsonObject underlyingJson = value.underlyingJson();
-        assertEquals(1, underlyingJson.entrySet()
-                                      .size());
-        Map.Entry<String, JsonElement> entry = underlyingJson.entrySet()
-                                                             .iterator()
-                                                             .next();
-        String valueString = entry.getValue()
-                                  .getAsString();
-        assertEquals(childValue.value(), valueString);
+        Set<Map.Entry<String, JsonElement>> entries = underlyingJson.entrySet();
+        assertThat(entries)
+                .hasSize(1);
+
+        String valueString = Iterators
+                .getOnlyElement(entries.iterator())
+                .getValue()
+                .getAsString();
+        assertThat(valueString)
+                .isEqualTo(childValue.value());
     }
 
     private static void
@@ -87,6 +91,7 @@ private static void assertSingleChild(NodeValue value, StoredJson childValue) {
         assertTrue(underlyingJson.has(childKey));
         String actual = underlyingJson.get(childKey)
                                       .getAsString();
-        assertEquals(childValue.value(), actual);
+        assertThat(actual)
+                .isEqualTo(childValue.value());
     }
 }
diff --git a/firebase-web/src/test/java/io/spine/web/firebase/given/FirebaseSubscriptionBridgeTestEnv.java b/firebase-web/src/test/java/io/spine/web/firebase/given/FirebaseSubscriptionBridgeTestEnv.java
index 1ac620e94..c322af6e7 100644
--- a/firebase-web/src/test/java/io/spine/web/firebase/given/FirebaseSubscriptionBridgeTestEnv.java
+++ b/firebase-web/src/test/java/io/spine/web/firebase/given/FirebaseSubscriptionBridgeTestEnv.java
@@ -64,7 +64,8 @@ public static void assertSubscriptionPointsToFirebase(NodePath path, Topic topic
                 DEFAULT_TENANT, escaped(actor), topic.getId().getValue()
         );
         String expectedPath = PATH_JOINER.join(pathElements);
-        assertThat(path.getValue()).isEqualTo(expectedPath);
+        assertThat(path.getValue())
+                .isEqualTo(expectedPath);
     }
 
     private static String actorAsString(Topic topic) {
diff --git a/firebase-web/src/test/java/io/spine/web/firebase/query/FirebaseQueryBridgeTest.java b/firebase-web/src/test/java/io/spine/web/firebase/query/FirebaseQueryBridgeTest.java
index 3680090de..a8eee6f6f 100644
--- a/firebase-web/src/test/java/io/spine/web/firebase/query/FirebaseQueryBridgeTest.java
+++ b/firebase-web/src/test/java/io/spine/web/firebase/query/FirebaseQueryBridgeTest.java
@@ -21,7 +21,6 @@
 package io.spine.web.firebase.query;
 
 import com.google.common.collect.Iterators;
-import com.google.common.truth.Truth;
 import com.google.gson.JsonElement;
 import com.google.gson.JsonObject;
 import com.google.protobuf.Message;
@@ -79,8 +78,7 @@ void requireQueryService() {
     void requireFirebaseClient() {
         QueryService queryService = QueryService
                 .newBuilder()
-                .add(BoundedContextBuilder.assumingTests()
-                                          .build())
+                .add(BoundedContextBuilder.assumingTests().build())
                 .build();
         FirebaseQueryBridge.Builder builder = FirebaseQueryBridge
                 .newBuilder()
@@ -99,7 +97,7 @@ void testMediate() {
                 .build();
         Query query = queryFactory.all(Event.class);
         FirebaseQueryResponse response = bridge.send(query);
-        Truth.assertThat(response)
+        assertThat(response)
              .isNotNull();
     }
 
@@ -125,7 +123,8 @@ void testWriteData() {
         FirebaseQueryResponse response = bridge.send(query);
         NodeValue nodeValue = firebaseClient.valueFor(NodePaths.of(response.getPath()));
         Book actual = firstFieldOf(nodeValue, Book.class);
-        assertThat(actual).isEqualTo(book);
+        assertThat(actual)
+                .isEqualTo(book);
     }
 
     /**
diff --git a/firebase-web/src/test/java/io/spine/web/firebase/rest/RemoteDatabaseClientTest.java b/firebase-web/src/test/java/io/spine/web/firebase/rest/RemoteDatabaseClientTest.java
index f50d53415..0721d36e2 100644
--- a/firebase-web/src/test/java/io/spine/web/firebase/rest/RemoteDatabaseClientTest.java
+++ b/firebase-web/src/test/java/io/spine/web/firebase/rest/RemoteDatabaseClientTest.java
@@ -47,14 +47,13 @@
 import java.util.Optional;
 
 import static com.google.common.truth.Truth.assertThat;
+import static com.google.common.truth.Truth8.assertThat;
 import static io.spine.testing.DisplayNames.NOT_ACCEPT_NULLS;
 import static io.spine.web.firebase.rest.HttpClientMockFactory.mockHttpClient;
 import static io.spine.web.firebase.rest.HttpClientMockFactory.noOpClient;
 import static org.junit.jupiter.api.Assertions.assertEquals;
-import static org.junit.jupiter.api.Assertions.assertFalse;
 import static org.junit.jupiter.api.Assertions.assertNotNull;
 import static org.junit.jupiter.api.Assertions.assertThrows;
-import static org.junit.jupiter.api.Assertions.assertTrue;
 
 @DisplayName("`RemoteDatabaseClient` should")
 class RemoteDatabaseClientTest {
@@ -113,7 +112,8 @@ void getData() {
         FirebaseClient client = new RemoteDatabaseClient(database, NODE_FACTORY, httpClient);
 
         Optional<NodeValue> result = client.fetchNode(path);
-        assertTrue(result.isPresent());
+        assertThat(result)
+                .isPresent();
         NodeValue value = result.get();
         String contentString = value.underlyingJson()
                                     .toString();
@@ -127,15 +127,18 @@ void getNullData() {
         FirebaseClient client = new RemoteDatabaseClient(database, NODE_FACTORY, httpClient);
 
         Optional<NodeValue> result = client.fetchNode(path);
-        assertFalse(result.isPresent());
+        assertThat(result)
+                .isPresent();
     }
 
     @Test
     @DisplayName("store data via PUT method when node is not present")
     void storeNewViaPut() {
         HttpClient httpClient = mockHttpClient(NULL_ENTRY, (method, url) -> {
-            assertThat(method).isEqualTo(HttpMethods.PUT);
-            assertThat(url).isEqualTo(EXPECTED_NODE_URL.build());
+            assertThat(method)
+                    .isEqualTo(HttpMethods.PUT);
+            assertThat(url)
+                    .isEqualTo(EXPECTED_NODE_URL.build());
         });
         FirebaseClient client = new RemoteDatabaseClient(database, NODE_FACTORY, httpClient);
 
@@ -146,8 +149,10 @@ void storeNewViaPut() {
     @DisplayName("store data via PATCH method when node already exists")
     void updateExistingViaPatch() {
         HttpClient httpClient = mockHttpClient(NULL_ENTRY, (method, url) -> {
-            assertThat(method).isEqualTo(HttpMethods.PATCH);
-            assertThat(url).isEqualTo(EXPECTED_NODE_URL.build());
+            assertThat(method)
+                    .isEqualTo(HttpMethods.PATCH);
+            assertThat(url)
+                    .isEqualTo(EXPECTED_NODE_URL.build());
         });
         FirebaseClient client = new RemoteDatabaseClient(database, NODE_FACTORY, httpClient);
 
diff --git a/firebase-web/src/test/java/io/spine/web/firebase/subscription/FirebaseSubscriptionBridgeTest.java b/firebase-web/src/test/java/io/spine/web/firebase/subscription/FirebaseSubscriptionBridgeTest.java
index ecc976c87..feabe884b 100644
--- a/firebase-web/src/test/java/io/spine/web/firebase/subscription/FirebaseSubscriptionBridgeTest.java
+++ b/firebase-web/src/test/java/io/spine/web/firebase/subscription/FirebaseSubscriptionBridgeTest.java
@@ -87,7 +87,8 @@ void keepUpSubscription() {
         FirebaseSubscription subscription = bridge.subscribe(topic);
         Response keptUp = bridge.keepUp(subscription.getSubscription());
         Response responseMessage = newResponse();
-        assertThat(keptUp).isEqualTo(responseMessage);
+        assertThat(keptUp)
+                .isEqualTo(responseMessage);
     }
 
     @Test
@@ -96,7 +97,8 @@ void failKeepUp() {
         Topic topic = topicFactory.forTarget(newTarget());
         Subscription subscription = newSubscription(topic);
         Response keptUp = bridge.keepUp(subscription);
-        assertThat(keptUp.getStatus().getStatusCase()).isEqualTo(ERROR);
+        assertThat(keptUp.getStatus().getStatusCase())
+                .isEqualTo(ERROR);
     }
 
     @Test
@@ -110,7 +112,8 @@ void cancelSubscription() {
         Response canceled = bridge.cancel(subscription);
         Response responseMessage = newResponse();
 
-        assertThat(canceled).isEqualTo(responseMessage);
+        assertThat(canceled)
+                .isEqualTo(responseMessage);
     }
 
     @Test
@@ -119,7 +122,8 @@ void failCancellation() {
         Topic topic = topicFactory.forTarget(newTarget());
         Subscription subscription = newSubscription(topic);
         Response canceled = bridge.cancel(subscription);
-        assertThat(canceled.getStatus().getStatusCase()).isEqualTo(ERROR);
+        assertThat(canceled.getStatus().getStatusCase())
+                .isEqualTo(ERROR);
     }
 
     @Test
@@ -127,11 +131,16 @@ void failCancellation() {
     void failDoubleCancellation() {
         Topic topic = topicFactory.forTarget(newTarget());
         FirebaseSubscription subscriptionResult = bridge.subscribe(topic);
-        assertThat(subscriptionResult).isNotNull();
+        assertThat(subscriptionResult)
+                .isNotNull();
+
         Response canceled = bridge.cancel(subscriptionResult.getSubscription());
-        assertThat(canceled.getStatus().getStatusCase()).isEqualTo(OK);
+        assertThat(canceled.getStatus().getStatusCase())
+                .isEqualTo(OK);
+
         Response canceledAgain = bridge.cancel(subscriptionResult.getSubscription());
-        assertThat(canceledAgain.getStatus().getStatusCase()).isEqualTo(ERROR);
+        assertThat(canceledAgain.getStatus().getStatusCase())
+                .isEqualTo(ERROR);
     }
 
     @Test
@@ -141,7 +150,8 @@ void subscribe() {
 
         FirebaseSubscription firebaseSubscription = bridge.subscribe(topic);
         Subscription subscription = firebaseSubscription.getSubscription();
-        assertThat(subscription.getTopic()).isEqualTo(topic);
+        assertThat(subscription.getTopic())
+                .isEqualTo(topic);
         assertSubscriptionPointsToFirebase(firebaseSubscription.getNodePath(), topic);
     }
 }

From 5db8ff6078b2154dd382134503a46c5bbd6e322c Mon Sep 17 00:00:00 2001
From: Yuri Sergiichuk <yuri.sergiichuk@teamdev.com>
Date: Mon, 7 Dec 2020 12:58:37 +0200
Subject: [PATCH 24/41] Add missing docs.

---
 .../java/io/spine/web/firebase/given/MemoizedFirebase.java  | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/firebase-web/src/test/java/io/spine/web/firebase/given/MemoizedFirebase.java b/firebase-web/src/test/java/io/spine/web/firebase/given/MemoizedFirebase.java
index 8046a9553..e2bcda888 100644
--- a/firebase-web/src/test/java/io/spine/web/firebase/given/MemoizedFirebase.java
+++ b/firebase-web/src/test/java/io/spine/web/firebase/given/MemoizedFirebase.java
@@ -55,10 +55,16 @@ private MemoizedFirebase(Duration latency) {
         this.writeLatency = latency;
     }
 
+    /**
+     * Creates a new instance with zero latency.
+     */
     public static MemoizedFirebase withNoLatency() {
         return withSimulatedLatency(Duration.ZERO);
     }
 
+    /**
+     * Creates a new instance with simulated {@code latency}.
+     */
     public static MemoizedFirebase withSimulatedLatency(Duration latency) {
         checkNotNull(latency);
         return new MemoizedFirebase(latency);

From 7e6bf4ccba9733be25417656255d252de03a22c2 Mon Sep 17 00:00:00 2001
From: Yuri Sergiichuk <yuri.sergiichuk@teamdev.com>
Date: Mon, 7 Dec 2020 12:59:16 +0200
Subject: [PATCH 25/41] Do not use Guava to create `ArrayList`.

---
 .../java/io/spine/web/firebase/given/MemoizedFirebase.java  | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/firebase-web/src/test/java/io/spine/web/firebase/given/MemoizedFirebase.java b/firebase-web/src/test/java/io/spine/web/firebase/given/MemoizedFirebase.java
index e2bcda888..9407b65df 100644
--- a/firebase-web/src/test/java/io/spine/web/firebase/given/MemoizedFirebase.java
+++ b/firebase-web/src/test/java/io/spine/web/firebase/given/MemoizedFirebase.java
@@ -28,13 +28,13 @@
 import io.spine.web.firebase.NodeValue;
 
 import java.time.Duration;
+import java.util.ArrayList;
+import java.util.Collection;
 import java.util.HashMap;
-import java.util.List;
 import java.util.Map;
 import java.util.Optional;
 
 import static com.google.common.base.Preconditions.checkNotNull;
-import static com.google.common.collect.Lists.newArrayList;
 import static com.google.common.util.concurrent.Uninterruptibles.sleepUninterruptibly;
 import static io.spine.util.Exceptions.newIllegalStateException;
 
@@ -47,7 +47,7 @@
 public final class MemoizedFirebase implements FirebaseClient {
 
     private final Map<NodePath, NodeValue> writes = new HashMap<>();
-    private final List<NodePath> reads = newArrayList();
+    private final Collection<NodePath> reads = new ArrayList<>();
 
     private final Duration writeLatency;
 

From 4b9deea6c00708dc77199c6e58f959a46530b412 Mon Sep 17 00:00:00 2001
From: Yuri Sergiichuk <yuri.sergiichuk@teamdev.com>
Date: Mon, 7 Dec 2020 13:07:20 +0200
Subject: [PATCH 26/41] Add missing backticks and improve annotations ordering.

---
 .../spine/web/firebase/query/FirebaseQueryBridgeTest.java   | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/firebase-web/src/test/java/io/spine/web/firebase/query/FirebaseQueryBridgeTest.java b/firebase-web/src/test/java/io/spine/web/firebase/query/FirebaseQueryBridgeTest.java
index a8eee6f6f..1620f1075 100644
--- a/firebase-web/src/test/java/io/spine/web/firebase/query/FirebaseQueryBridgeTest.java
+++ b/firebase-web/src/test/java/io/spine/web/firebase/query/FirebaseQueryBridgeTest.java
@@ -49,7 +49,7 @@
 import static io.spine.base.Identifier.newUuid;
 import static org.junit.jupiter.api.Assertions.assertThrows;
 
-@DisplayName("FirebaseQueryBridge should")
+@DisplayName("`FirebaseQueryBridge` should")
 class FirebaseQueryBridgeTest {
 
     private static final QueryFactory queryFactory =
@@ -58,7 +58,7 @@ class FirebaseQueryBridgeTest {
     private MemoizedFirebase firebaseClient;
 
     @BeforeEach
-    void setUp() {
+    void initClient() {
         firebaseClient = MemoizedFirebase.withNoLatency();
     }
 
@@ -72,9 +72,9 @@ void requireQueryService() {
         assertThrows(IllegalStateException.class, builder::build);
     }
 
-    @SuppressWarnings({"ResultOfMethodCallIgnored", "CheckReturnValue"}) // Method called to throw.
     @Test
     @DisplayName("require Firebase Client set in class Builder")
+    @SuppressWarnings({"ResultOfMethodCallIgnored", "CheckReturnValue"}) // Method called to throw.
     void requireFirebaseClient() {
         QueryService queryService = QueryService
                 .newBuilder()

From 24618637117cd87006239495c7af780af64cffe3 Mon Sep 17 00:00:00 2001
From: Yuri Sergiichuk <yuri.sergiichuk@teamdev.com>
Date: Mon, 7 Dec 2020 13:49:33 +0200
Subject: [PATCH 27/41] Improve usage.

---
 .../spine/web/command/CommandServletTest.java |  8 +++++---
 .../spine/web/future/FutureObserverTest.java  | 20 ++++++++++++-------
 .../io/spine/web/query/QueryServletTest.java  |  6 +++---
 3 files changed, 21 insertions(+), 13 deletions(-)

diff --git a/web/src/test/java/io/spine/web/command/CommandServletTest.java b/web/src/test/java/io/spine/web/command/CommandServletTest.java
index 20ab0c65d..7f3faf09e 100644
--- a/web/src/test/java/io/spine/web/command/CommandServletTest.java
+++ b/web/src/test/java/io/spine/web/command/CommandServletTest.java
@@ -41,11 +41,11 @@
 import java.io.StringWriter;
 
 import static com.google.common.truth.Truth.assertThat;
+import static com.google.common.truth.extensions.proto.ProtoTruth.assertThat;
 import static io.spine.base.Identifier.newUuid;
 import static io.spine.web.given.Servlets.request;
 import static io.spine.web.given.Servlets.response;
 import static javax.servlet.http.HttpServletResponse.SC_BAD_REQUEST;
-import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertThrows;
 
 @DisplayName("`CommandServlet` should")
@@ -75,7 +75,8 @@ void testHandle() throws IOException {
         Command command = commandFactory.create(createTask);
         servlet.doPost(request(command), response(response));
         Ack ack = Json.fromJson(response.toString(), Ack.class);
-        assertEquals(command.getId(), AnyPacker.unpack(ack.getMessageId()));
+        assertThat(command.getId())
+                .isEqualTo(AnyPacker.unpack(ack.getMessageId()));
     }
 
     @MuteLogging
@@ -85,6 +86,7 @@ void testInvalidCommand() throws IOException {
         CommandServlet servlet = new DetachedCommandServlet();
         SettableResponse response = new SettableResponse();
         servlet.doPost(request(Time.currentTime()), response);
-        assertThat(response.getStatus()).isEqualTo(SC_BAD_REQUEST);
+        assertThat(response.getStatus())
+                .isEqualTo(SC_BAD_REQUEST);
     }
 }
diff --git a/web/src/test/java/io/spine/web/future/FutureObserverTest.java b/web/src/test/java/io/spine/web/future/FutureObserverTest.java
index 4435f737f..d784c0849 100644
--- a/web/src/test/java/io/spine/web/future/FutureObserverTest.java
+++ b/web/src/test/java/io/spine/web/future/FutureObserverTest.java
@@ -41,9 +41,11 @@ void testCreateDefault() {
         FutureObserver<String> observer = FutureObserver.create();
         String value = "hello";
         observer.onNext(value);
-        assertResult(observer).isEqualTo(value);
+        assertResult(observer)
+                .isEqualTo(value);
         observer.onCompleted();
-        assertResult(observer).isEqualTo(value);
+        assertResult(observer)
+                .isEqualTo(value);
     }
 
     @Test
@@ -51,7 +53,8 @@ void testCreateDefault() {
     void testDefaultNull() {
         FutureObserver<String> observer = FutureObserver.create();
         observer.onCompleted();
-        assertResult(observer).isNull();
+        assertResult(observer)
+                .isNull();
     }
 
     @Test
@@ -60,7 +63,8 @@ void testDefaultValue() {
         String defaultValue = "Aquaman";
         FutureObserver<String> observer = FutureObserver.withDefault(defaultValue);
         observer.onCompleted();
-        assertResult(observer).isEqualTo(defaultValue);
+        assertResult(observer)
+                .isEqualTo(defaultValue);
     }
 
     @Test
@@ -77,15 +81,17 @@ void testOverrideWithError() {
         FutureObserver<String> observer = FutureObserver.create();
         String value = "Titanic";
         observer.onNext(value);
-        assertEquals(value, observer.toFuture()
-                                    .join());
+        assertResult(observer)
+                .isEqualTo(value);
+
         observer.onError(new IcebergCollisionException());
         Throwable thrown = assertThrows(
                 CompletionException.class,
                 () -> observerResult(observer)
         );
         Throwable rootCause = getRootCause(thrown);
-        assertThat(rootCause).isInstanceOf(IcebergCollisionException.class);
+        assertThat(rootCause)
+                .isInstanceOf(IcebergCollisionException.class);
     }
 
     private static StringSubject assertResult(FutureObserver<String> observer) {
diff --git a/web/src/test/java/io/spine/web/query/QueryServletTest.java b/web/src/test/java/io/spine/web/query/QueryServletTest.java
index c8edfe5e4..88130b1f1 100644
--- a/web/src/test/java/io/spine/web/query/QueryServletTest.java
+++ b/web/src/test/java/io/spine/web/query/QueryServletTest.java
@@ -20,7 +20,6 @@
 
 package io.spine.web.query;
 
-import com.google.common.truth.Truth;
 import com.google.protobuf.Message;
 import io.spine.client.Query;
 import io.spine.client.QueryFactory;
@@ -40,6 +39,7 @@
 import java.io.ObjectOutputStream;
 import java.io.StringWriter;
 
+import static com.google.common.truth.Truth.assertThat;
 import static com.google.common.truth.extensions.proto.ProtoTruth.assertThat;
 import static io.spine.base.Time.currentTime;
 import static io.spine.web.given.Servlets.request;
@@ -86,7 +86,7 @@ void testInvalidQuery() throws IOException {
         QueryServlet<Message> servlet = new TestQueryServlet();
         SettableResponse response = new SettableResponse();
         servlet.doPost(request(currentTime()), response);
-        Truth.assertThat(response.getStatus())
-             .isEqualTo(SC_BAD_REQUEST);
+        assertThat(response.getStatus())
+                .isEqualTo(SC_BAD_REQUEST);
     }
 }

From 5bb44f98e4741cf160e04244689887d7f29bb690 Mon Sep 17 00:00:00 2001
From: Yuri Sergiichuk <yuri.sergiichuk@teamdev.com>
Date: Mon, 7 Dec 2020 13:57:34 +0200
Subject: [PATCH 28/41] The optional should be `empty`.

---
 .../io/spine/web/firebase/rest/RemoteDatabaseClientTest.java    | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/firebase-web/src/test/java/io/spine/web/firebase/rest/RemoteDatabaseClientTest.java b/firebase-web/src/test/java/io/spine/web/firebase/rest/RemoteDatabaseClientTest.java
index 0721d36e2..d0d74946e 100644
--- a/firebase-web/src/test/java/io/spine/web/firebase/rest/RemoteDatabaseClientTest.java
+++ b/firebase-web/src/test/java/io/spine/web/firebase/rest/RemoteDatabaseClientTest.java
@@ -128,7 +128,7 @@ void getNullData() {
 
         Optional<NodeValue> result = client.fetchNode(path);
         assertThat(result)
-                .isPresent();
+                .isEmpty();
     }
 
     @Test

From 065ffd0e1c5ed80fef9551600487abe6221ebd19 Mon Sep 17 00:00:00 2001
From: Yuri Sergiichuk <yuri.sergiichuk@teamdev.com>
Date: Mon, 7 Dec 2020 13:58:01 +0200
Subject: [PATCH 29/41] Update report time.

---
 license-report.md | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/license-report.md b/license-report.md
index f7546c2d4..900b84bef 100644
--- a/license-report.md
+++ b/license-report.md
@@ -368,7 +368,7 @@
  The dependencies distributed under several licenses, are used according their commercial-use-friendly license.
 
 
-This report was generated on **Mon Dec 07 12:18:22 EET 2020** using [Gradle-License-Report plugin](https://github.com/jk1/Gradle-License-Report) by Evgeny Naumenko, licensed under [Apache 2.0 License](https://github.com/jk1/Gradle-License-Report/blob/master/LICENSE).
+This report was generated on **Mon Dec 07 12:28:03 EET 2020** using [Gradle-License-Report plugin](https://github.com/jk1/Gradle-License-Report) by Evgeny Naumenko, licensed under [Apache 2.0 License](https://github.com/jk1/Gradle-License-Report/blob/master/LICENSE).
 
 
 #NPM dependencies of `spine-web@1.6.16`
@@ -2755,7 +2755,7 @@ This report was generated on **Mon Dec 07 12:18:22 EET 2020** using [Gradle-Lice
      * Repository: [https://github.com/yargs/yargs](https://github.com/yargs/yargs)
 
 
-This report was generated on **Mon Dec 07 2020 12:18:24 GMT+0200 (Eastern European Standard Time)** using [NPM License Checker](https://github.com/davglass/license-checker) library.
+This report was generated on **Mon Dec 07 2020 12:28:06 GMT+0200 (Eastern European Standard Time)** using [NPM License Checker](https://github.com/davglass/license-checker) library.
 
 
 

From ac73924a610279e065fbd8ff826ccbcaa4d1a20a Mon Sep 17 00:00:00 2001
From: Yuri Sergiichuk <yuri.sergiichuk@teamdev.com>
Date: Mon, 7 Dec 2020 15:35:22 +0200
Subject: [PATCH 30/41] Add tests for test utilities.

---
 .../io/spine/web/given/SettableResponse.java  |  5 ++
 .../web/given/FixedContentRequestTest.java    | 71 +++++++++++++++++++
 .../web/given/FixedContentResponseTest.java   | 67 +++++++++++++++++
 .../spine/web/given/SettableResponseTest.java | 52 ++++++++++++++
 4 files changed, 195 insertions(+)
 create mode 100644 testutil-web/src/test/java/io/spine/web/given/FixedContentRequestTest.java
 create mode 100644 testutil-web/src/test/java/io/spine/web/given/FixedContentResponseTest.java
 create mode 100644 testutil-web/src/test/java/io/spine/web/given/SettableResponseTest.java

diff --git a/testutil-web/src/main/java/io/spine/web/given/SettableResponse.java b/testutil-web/src/main/java/io/spine/web/given/SettableResponse.java
index dcabe8ddf..75945c94c 100644
--- a/testutil-web/src/main/java/io/spine/web/given/SettableResponse.java
+++ b/testutil-web/src/main/java/io/spine/web/given/SettableResponse.java
@@ -49,6 +49,11 @@ public int getStatus() {
         return headers.get(name);
     }
 
+    @Override
+    public void addHeader(String name, String value) {
+        headers.put(name, value);
+    }
+
     @Override
     public void sendError(int sc) {
         status = sc;
diff --git a/testutil-web/src/test/java/io/spine/web/given/FixedContentRequestTest.java b/testutil-web/src/test/java/io/spine/web/given/FixedContentRequestTest.java
new file mode 100644
index 000000000..6ce16f3b4
--- /dev/null
+++ b/testutil-web/src/test/java/io/spine/web/given/FixedContentRequestTest.java
@@ -0,0 +1,71 @@
+/*
+ * Copyright 2020, TeamDev. All rights reserved.
+ *
+ * Redistribution and use in source and/or binary forms, with or without
+ * modification, must retain the above copyright notice and the following
+ * disclaimer.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+package io.spine.web.given;
+
+import com.google.common.collect.ImmutableMap;
+import com.google.common.net.MediaType;
+import com.google.common.testing.NullPointerTester;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+
+import java.io.IOException;
+
+import static com.google.common.truth.Truth.assertThat;
+
+@DisplayName("`FixedContentRequest` should")
+class FixedContentRequestTest {
+
+    @Test
+    @DisplayName("not tolerate `null`s")
+    void notTolerateNull() {
+        NullPointerTester tester = new NullPointerTester();
+        tester.testAllPublicStaticMethods(FixedContentRequest.class);
+    }
+
+    @Test
+    @DisplayName("return set values")
+    @SuppressWarnings("JdkObsolete") // we're force to follow the contract
+    void returnSetValues() throws IOException {
+        String text = "some text";
+        MediaType type = MediaType.PLAIN_TEXT_UTF_8;
+        String headerName = "custom";
+        String headerValue = "header";
+        ImmutableMap<String, String> headers = ImmutableMap.of(headerName, headerValue);
+        FixedContentRequest request = FixedContentRequest.create(text, type, headers);
+        assertThat(request.getContentLength())
+                .isEqualTo(text.length());
+        assertThat(request.getContentLengthLong())
+                .isEqualTo(text.length());
+        assertThat(request.getHeader(headerName))
+                .isEqualTo(headerValue);
+        assertThat(request.getHeaders(headerName)
+                          .nextElement())
+                .isEqualTo(headerValue);
+        assertThat(request.getHeaders("non-existing")
+                          .hasMoreElements())
+                .isFalse();
+        assertThat(request.getContentType())
+                .isEqualTo(type.toString());
+        assertThat(request.getReader()
+                          .readLine())
+                .isEqualTo(text);
+    }
+}
diff --git a/testutil-web/src/test/java/io/spine/web/given/FixedContentResponseTest.java b/testutil-web/src/test/java/io/spine/web/given/FixedContentResponseTest.java
new file mode 100644
index 000000000..3697f82d4
--- /dev/null
+++ b/testutil-web/src/test/java/io/spine/web/given/FixedContentResponseTest.java
@@ -0,0 +1,67 @@
+/*
+ * Copyright 2020, TeamDev. All rights reserved.
+ *
+ * Redistribution and use in source and/or binary forms, with or without
+ * modification, must retain the above copyright notice and the following
+ * disclaimer.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+package io.spine.web.given;
+
+import com.google.common.collect.ImmutableMap;
+import com.google.common.collect.ImmutableSet;
+import com.google.common.testing.NullPointerTester;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+
+import java.io.PrintWriter;
+import java.io.StringWriter;
+
+import static com.google.common.truth.Truth.assertThat;
+import static javax.servlet.http.HttpServletResponse.SC_ACCEPTED;
+
+@DisplayName("`FixedContentResponse` should")
+class FixedContentResponseTest {
+
+    @Test
+    @DisplayName("not tolerate `null`s")
+    void notTolerateNull() {
+        NullPointerTester tester = new NullPointerTester();
+        tester.testAllPublicStaticMethods(FixedContentResponse.class);
+    }
+
+    @Test
+    @DisplayName("return set values")
+    @SuppressWarnings("JdkObsolete") // we're force to follow the contract
+    void returnSetValues() {
+        String headerName = "custom";
+        String headerValue = "header";
+        ImmutableMap<String, String> headers = ImmutableMap.of(headerName, headerValue);
+        StringWriter writer = new StringWriter();
+        FixedContentResponse response = FixedContentResponse.create(writer, SC_ACCEPTED, headers);
+        assertThat(response.getStatus())
+                .isEqualTo(SC_ACCEPTED);
+        assertThat(response.getHeader(headerName))
+                .isEqualTo(headerValue);
+        assertThat(response.getHeaders(headerName))
+                .isEqualTo(ImmutableSet.of(headerValue));
+        assertThat(response.getHeaderNames())
+                .isEqualTo(ImmutableSet.of(headerName));
+        PrintWriter printWriter = response.getWriter();
+        printWriter.print("Unbelievable string!");
+        assertThat(writer.toString())
+                .isEqualTo("Unbelievable string!");
+    }
+}
diff --git a/testutil-web/src/test/java/io/spine/web/given/SettableResponseTest.java b/testutil-web/src/test/java/io/spine/web/given/SettableResponseTest.java
new file mode 100644
index 000000000..bc94161ae
--- /dev/null
+++ b/testutil-web/src/test/java/io/spine/web/given/SettableResponseTest.java
@@ -0,0 +1,52 @@
+/*
+ * Copyright 2020, TeamDev. All rights reserved.
+ *
+ * Redistribution and use in source and/or binary forms, with or without
+ * modification, must retain the above copyright notice and the following
+ * disclaimer.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+package io.spine.web.given;
+
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+
+import java.io.PrintWriter;
+
+import static com.google.common.truth.Truth.assertThat;
+import static javax.servlet.http.HttpServletResponse.SC_BAD_GATEWAY;
+
+@DisplayName("`SettableResponse` should")
+class SettableResponseTest {
+
+    @Test
+    @DisplayName("return set values")
+    @SuppressWarnings("JdkObsolete") // we're force to follow the contract
+    void returnSetValues() {
+        String headerName = "custom";
+        String headerValue = "header";
+        SettableResponse response = new SettableResponse();
+        response.sendError(SC_BAD_GATEWAY);
+        assertThat(response.getStatus())
+                .isEqualTo(SC_BAD_GATEWAY);
+        response.addHeader(headerName, headerValue);
+        assertThat(response.getHeader(headerName))
+                .isEqualTo(headerValue);
+        PrintWriter printWriter = response.getWriter();
+        printWriter.print("I'm writing you!");
+        assertThat(response.writerContent())
+                .isEqualTo("I'm writing you!");
+    }
+}

From e691bc12273b98937777e0a00e2cb0c61ab675e2 Mon Sep 17 00:00:00 2001
From: Yuri Sergiichuk <yuri.sergiichuk@teamdev.com>
Date: Mon, 7 Dec 2020 18:12:50 +0200
Subject: [PATCH 31/41] Rename `SettableResponse` to `MemoizingResponse`.

---
 .../given/{SettableResponse.java => MemoizingResponse.java} | 4 ++--
 ...SettableResponseTest.java => MemoizingResponseTest.java} | 6 +++---
 .../test/java/io/spine/web/command/CommandServletTest.java  | 4 ++--
 web/src/test/java/io/spine/web/query/QueryServletTest.java  | 4 ++--
 4 files changed, 9 insertions(+), 9 deletions(-)
 rename testutil-web/src/main/java/io/spine/web/given/{SettableResponse.java => MemoizingResponse.java} (95%)
 rename testutil-web/src/test/java/io/spine/web/given/{SettableResponseTest.java => MemoizingResponseTest.java} (93%)

diff --git a/testutil-web/src/main/java/io/spine/web/given/SettableResponse.java b/testutil-web/src/main/java/io/spine/web/given/MemoizingResponse.java
similarity index 95%
rename from testutil-web/src/main/java/io/spine/web/given/SettableResponse.java
rename to testutil-web/src/main/java/io/spine/web/given/MemoizingResponse.java
index 75945c94c..d4c7e38f5 100644
--- a/testutil-web/src/main/java/io/spine/web/given/SettableResponse.java
+++ b/testutil-web/src/main/java/io/spine/web/given/MemoizingResponse.java
@@ -30,9 +30,9 @@
 import java.util.Set;
 
 /**
- * A mocked response whose {@code status} and {@code type} could be set.
+ * A mocked response that attempts to save all the actions done to it.
  */
-public final class SettableResponse implements MockedResponse {
+public final class MemoizingResponse implements MockedResponse {
 
     private final StringWriter writer = new StringWriter();
     private final Map<String, String> headers = new HashMap<>();
diff --git a/testutil-web/src/test/java/io/spine/web/given/SettableResponseTest.java b/testutil-web/src/test/java/io/spine/web/given/MemoizingResponseTest.java
similarity index 93%
rename from testutil-web/src/test/java/io/spine/web/given/SettableResponseTest.java
rename to testutil-web/src/test/java/io/spine/web/given/MemoizingResponseTest.java
index bc94161ae..8478a5369 100644
--- a/testutil-web/src/test/java/io/spine/web/given/SettableResponseTest.java
+++ b/testutil-web/src/test/java/io/spine/web/given/MemoizingResponseTest.java
@@ -28,8 +28,8 @@
 import static com.google.common.truth.Truth.assertThat;
 import static javax.servlet.http.HttpServletResponse.SC_BAD_GATEWAY;
 
-@DisplayName("`SettableResponse` should")
-class SettableResponseTest {
+@DisplayName("`MemoizingResponse` should")
+class MemoizingResponseTest {
 
     @Test
     @DisplayName("return set values")
@@ -37,7 +37,7 @@ class SettableResponseTest {
     void returnSetValues() {
         String headerName = "custom";
         String headerValue = "header";
-        SettableResponse response = new SettableResponse();
+        MemoizingResponse response = new MemoizingResponse();
         response.sendError(SC_BAD_GATEWAY);
         assertThat(response.getStatus())
                 .isEqualTo(SC_BAD_GATEWAY);
diff --git a/web/src/test/java/io/spine/web/command/CommandServletTest.java b/web/src/test/java/io/spine/web/command/CommandServletTest.java
index 7f3faf09e..6381b5d1f 100644
--- a/web/src/test/java/io/spine/web/command/CommandServletTest.java
+++ b/web/src/test/java/io/spine/web/command/CommandServletTest.java
@@ -30,7 +30,7 @@
 import io.spine.testing.client.command.TestCommandMessage;
 import io.spine.testing.logging.MuteLogging;
 import io.spine.web.command.given.DetachedCommandServlet;
-import io.spine.web.given.SettableResponse;
+import io.spine.web.given.MemoizingResponse;
 import org.junit.jupiter.api.DisplayName;
 import org.junit.jupiter.api.Test;
 
@@ -84,7 +84,7 @@ void testHandle() throws IOException {
     @DisplayName("respond 400 to an invalid command")
     void testInvalidCommand() throws IOException {
         CommandServlet servlet = new DetachedCommandServlet();
-        SettableResponse response = new SettableResponse();
+        MemoizingResponse response = new MemoizingResponse();
         servlet.doPost(request(Time.currentTime()), response);
         assertThat(response.getStatus())
                 .isEqualTo(SC_BAD_REQUEST);
diff --git a/web/src/test/java/io/spine/web/query/QueryServletTest.java b/web/src/test/java/io/spine/web/query/QueryServletTest.java
index 88130b1f1..ae1e08852 100644
--- a/web/src/test/java/io/spine/web/query/QueryServletTest.java
+++ b/web/src/test/java/io/spine/web/query/QueryServletTest.java
@@ -26,7 +26,7 @@
 import io.spine.json.Json;
 import io.spine.testing.client.TestActorRequestFactory;
 import io.spine.testing.logging.MuteLogging;
-import io.spine.web.given.SettableResponse;
+import io.spine.web.given.MemoizingResponse;
 import io.spine.web.query.given.QueryServletTestEnv.TestQueryServlet;
 import io.spine.web.test.Task;
 import io.spine.web.test.TaskId;
@@ -84,7 +84,7 @@ void testHandle() throws IOException {
     @DisplayName("respond 400 to an invalid query")
     void testInvalidQuery() throws IOException {
         QueryServlet<Message> servlet = new TestQueryServlet();
-        SettableResponse response = new SettableResponse();
+        MemoizingResponse response = new MemoizingResponse();
         servlet.doPost(request(currentTime()), response);
         assertThat(response.getStatus())
                 .isEqualTo(SC_BAD_REQUEST);

From 04a5b7cd9c47d60fe44bc7574caf76b1c524360f Mon Sep 17 00:00:00 2001
From: Yuri Sergiichuk <yuri.sergiichuk@teamdev.com>
Date: Mon, 7 Dec 2020 18:13:55 +0200
Subject: [PATCH 32/41] Rename `MemoizedFirebase` to `MemoizingFirebase`.

---
 .../java/io/spine/web/firebase/AsyncClientTest.java    |  6 +++---
 .../{MemoizedFirebase.java => MemoizingFirebase.java}  | 10 +++++-----
 .../web/firebase/query/FirebaseQueryBridgeTest.java    |  6 +++---
 .../subscription/FirebaseSubscriptionBridgeTest.java   |  6 +++---
 4 files changed, 14 insertions(+), 14 deletions(-)
 rename firebase-web/src/test/java/io/spine/web/firebase/given/{MemoizedFirebase.java => MemoizingFirebase.java} (93%)

diff --git a/firebase-web/src/test/java/io/spine/web/firebase/AsyncClientTest.java b/firebase-web/src/test/java/io/spine/web/firebase/AsyncClientTest.java
index b8047dbd8..38361496e 100644
--- a/firebase-web/src/test/java/io/spine/web/firebase/AsyncClientTest.java
+++ b/firebase-web/src/test/java/io/spine/web/firebase/AsyncClientTest.java
@@ -21,7 +21,7 @@
 package io.spine.web.firebase;
 
 import com.google.common.util.concurrent.Uninterruptibles;
-import io.spine.web.firebase.given.MemoizedFirebase;
+import io.spine.web.firebase.given.MemoizingFirebase;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.DisplayName;
 import org.junit.jupiter.api.Test;
@@ -37,7 +37,7 @@
 @DisplayName("`AsyncClient` should")
 class AsyncClientTest {
 
-    private MemoizedFirebase delegate;
+    private MemoizingFirebase delegate;
     private NodePath path;
     private ExecutorService executor;
     private Duration latency;
@@ -45,7 +45,7 @@ class AsyncClientTest {
     @BeforeEach
     void setUp() {
         latency = ofSeconds(2);
-        delegate = MemoizedFirebase.withSimulatedLatency(latency);
+        delegate = MemoizingFirebase.withSimulatedLatency(latency);
         path = NodePaths.of("some/kind/of/path");
         executor = newSingleThreadExecutor();
     }
diff --git a/firebase-web/src/test/java/io/spine/web/firebase/given/MemoizedFirebase.java b/firebase-web/src/test/java/io/spine/web/firebase/given/MemoizingFirebase.java
similarity index 93%
rename from firebase-web/src/test/java/io/spine/web/firebase/given/MemoizedFirebase.java
rename to firebase-web/src/test/java/io/spine/web/firebase/given/MemoizingFirebase.java
index 9407b65df..d8c288b5b 100644
--- a/firebase-web/src/test/java/io/spine/web/firebase/given/MemoizedFirebase.java
+++ b/firebase-web/src/test/java/io/spine/web/firebase/given/MemoizingFirebase.java
@@ -44,30 +44,30 @@
  * <p>Supports having a custom write latency through {@linkplain #withSimulatedLatency(Duration)
  * setting} a particular write operations duration.
  */
-public final class MemoizedFirebase implements FirebaseClient {
+public final class MemoizingFirebase implements FirebaseClient {
 
     private final Map<NodePath, NodeValue> writes = new HashMap<>();
     private final Collection<NodePath> reads = new ArrayList<>();
 
     private final Duration writeLatency;
 
-    private MemoizedFirebase(Duration latency) {
+    private MemoizingFirebase(Duration latency) {
         this.writeLatency = latency;
     }
 
     /**
      * Creates a new instance with zero latency.
      */
-    public static MemoizedFirebase withNoLatency() {
+    public static MemoizingFirebase withNoLatency() {
         return withSimulatedLatency(Duration.ZERO);
     }
 
     /**
      * Creates a new instance with simulated {@code latency}.
      */
-    public static MemoizedFirebase withSimulatedLatency(Duration latency) {
+    public static MemoizingFirebase withSimulatedLatency(Duration latency) {
         checkNotNull(latency);
-        return new MemoizedFirebase(latency);
+        return new MemoizingFirebase(latency);
     }
 
     @Override
diff --git a/firebase-web/src/test/java/io/spine/web/firebase/query/FirebaseQueryBridgeTest.java b/firebase-web/src/test/java/io/spine/web/firebase/query/FirebaseQueryBridgeTest.java
index 1620f1075..07cba4565 100644
--- a/firebase-web/src/test/java/io/spine/web/firebase/query/FirebaseQueryBridgeTest.java
+++ b/firebase-web/src/test/java/io/spine/web/firebase/query/FirebaseQueryBridgeTest.java
@@ -36,7 +36,7 @@
 import io.spine.web.firebase.StoredJson;
 import io.spine.web.firebase.given.Book;
 import io.spine.web.firebase.given.BookId;
-import io.spine.web.firebase.given.MemoizedFirebase;
+import io.spine.web.firebase.given.MemoizingFirebase;
 import io.spine.web.given.TestQueryService;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.DisplayName;
@@ -55,11 +55,11 @@ class FirebaseQueryBridgeTest {
     private static final QueryFactory queryFactory =
             new TestActorRequestFactory(FirebaseQueryBridgeTest.class).query();
 
-    private MemoizedFirebase firebaseClient;
+    private MemoizingFirebase firebaseClient;
 
     @BeforeEach
     void initClient() {
-        firebaseClient = MemoizedFirebase.withNoLatency();
+        firebaseClient = MemoizingFirebase.withNoLatency();
     }
 
     @SuppressWarnings({"ResultOfMethodCallIgnored", "CheckReturnValue"}) // Method called to throw.
diff --git a/firebase-web/src/test/java/io/spine/web/firebase/subscription/FirebaseSubscriptionBridgeTest.java b/firebase-web/src/test/java/io/spine/web/firebase/subscription/FirebaseSubscriptionBridgeTest.java
index feabe884b..f4b770f36 100644
--- a/firebase-web/src/test/java/io/spine/web/firebase/subscription/FirebaseSubscriptionBridgeTest.java
+++ b/firebase-web/src/test/java/io/spine/web/firebase/subscription/FirebaseSubscriptionBridgeTest.java
@@ -27,7 +27,7 @@
 import io.spine.core.Response;
 import io.spine.server.BoundedContextBuilder;
 import io.spine.server.SubscriptionService;
-import io.spine.web.firebase.given.MemoizedFirebase;
+import io.spine.web.firebase.given.MemoizingFirebase;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.DisplayName;
 import org.junit.jupiter.api.Test;
@@ -52,7 +52,7 @@ class FirebaseSubscriptionBridgeTest {
     @BeforeEach
     void setUp() {
         SubscriptionServiceImplBase subscriptionService = new TestSubscriptionService();
-        bridge = newBridge(MemoizedFirebase.withNoLatency(), subscriptionService);
+        bridge = newBridge(MemoizingFirebase.withNoLatency(), subscriptionService);
         topicFactory = topicFactory();
     }
 
@@ -62,7 +62,7 @@ void setUp() {
     void requireQueryService() {
         FirebaseSubscriptionBridge.Builder builder = FirebaseSubscriptionBridge
                 .newBuilder()
-                .setFirebaseClient(MemoizedFirebase.withNoLatency());
+                .setFirebaseClient(MemoizingFirebase.withNoLatency());
         assertThrows(IllegalStateException.class, builder::build);
     }
 

From 8aeb29bb08e1f88706dcf5bf738c1bade76dd6bd Mon Sep 17 00:00:00 2001
From: Yuri Sergiichuk <yuri.sergiichuk@teamdev.com>
Date: Mon, 7 Dec 2020 18:14:37 +0200
Subject: [PATCH 33/41] Remove trailing dot.

---
 .../java/io/spine/web/firebase/given/MemoizingFirebase.java     | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/firebase-web/src/test/java/io/spine/web/firebase/given/MemoizingFirebase.java b/firebase-web/src/test/java/io/spine/web/firebase/given/MemoizingFirebase.java
index d8c288b5b..206f8bbeb 100644
--- a/firebase-web/src/test/java/io/spine/web/firebase/given/MemoizingFirebase.java
+++ b/firebase-web/src/test/java/io/spine/web/firebase/given/MemoizingFirebase.java
@@ -117,7 +117,7 @@ public ImmutableMap<NodePath, NodeValue> writes() {
      * Returns a {@code NodeValue} written to a specific {@code path}.
      *
      * @throws IllegalStateException
-     *         if no value is present for the path.
+     *         if no value is present for the path
      */
     public NodeValue valueFor(NodePath path) {
         NodeValue result = writes.get(path);

From 9548544503112a89c4f0b83fbfb5aa4f8e2b2752 Mon Sep 17 00:00:00 2001
From: Yuri Sergiichuk <yuri.sergiichuk@teamdev.com>
Date: Mon, 7 Dec 2020 18:15:19 +0200
Subject: [PATCH 34/41] Capitalize.

---
 .../io/spine/web/firebase/query/FirebaseQueryBridgeTest.java    | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/firebase-web/src/test/java/io/spine/web/firebase/query/FirebaseQueryBridgeTest.java b/firebase-web/src/test/java/io/spine/web/firebase/query/FirebaseQueryBridgeTest.java
index 07cba4565..8b483b165 100644
--- a/firebase-web/src/test/java/io/spine/web/firebase/query/FirebaseQueryBridgeTest.java
+++ b/firebase-web/src/test/java/io/spine/web/firebase/query/FirebaseQueryBridgeTest.java
@@ -133,7 +133,7 @@ void testWriteData() {
      * <p>The node has a single randomized field with the field value being a serialized
      * processed message.
      *
-     * @implNote the {@code nodeValue} holds data as a JSON primitive string (i.e. an
+     * @implNote The {@code nodeValue} holds data as a JSON primitive string (i.e. an
      *         escaped string that actually holds a JSON object), thus we're forced to parse
      *         the string into a JSON object first and then convert it back to a string.
      */

From 3a8d4a872595320205f9e7d0077b28e4ee895f12 Mon Sep 17 00:00:00 2001
From: Yuri Sergiichuk <yuri.sergiichuk@teamdev.com>
Date: Mon, 7 Dec 2020 18:24:00 +0200
Subject: [PATCH 35/41] Rename `FixedContent` to `Known` servlet mocks.

---
 ...dContentRequest.java => KnownRequest.java} | 33 +++++++++++--------
 ...ontentResponse.java => KnownResponse.java} | 28 +++++++++-------
 .../io/spine/web/given/MemoizingResponse.java |  5 +++
 ...RequestTest.java => KnownRequestTest.java} |  8 ++---
 ...sponseTest.java => KnownResponseTest.java} |  8 ++---
 .../java/io/spine/web/given/Servlets.java     |  6 ++--
 6 files changed, 52 insertions(+), 36 deletions(-)
 rename testutil-web/src/main/java/io/spine/web/given/{FixedContentRequest.java => KnownRequest.java} (79%)
 rename testutil-web/src/main/java/io/spine/web/given/{FixedContentResponse.java => KnownResponse.java} (73%)
 rename testutil-web/src/test/java/io/spine/web/given/{FixedContentRequestTest.java => KnownRequestTest.java} (91%)
 rename testutil-web/src/test/java/io/spine/web/given/{FixedContentResponseTest.java => KnownResponseTest.java} (91%)

diff --git a/testutil-web/src/main/java/io/spine/web/given/FixedContentRequest.java b/testutil-web/src/main/java/io/spine/web/given/KnownRequest.java
similarity index 79%
rename from testutil-web/src/main/java/io/spine/web/given/FixedContentRequest.java
rename to testutil-web/src/main/java/io/spine/web/given/KnownRequest.java
index 8b705c72b..7f3488eca 100644
--- a/testutil-web/src/main/java/io/spine/web/given/FixedContentRequest.java
+++ b/testutil-web/src/main/java/io/spine/web/given/KnownRequest.java
@@ -23,6 +23,7 @@
 import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.ImmutableSet;
 import com.google.common.net.MediaType;
+import com.google.errorprone.annotations.Immutable;
 import org.checkerframework.checker.nullness.qual.Nullable;
 
 import java.io.BufferedReader;
@@ -39,10 +40,14 @@
 /**
  * A mocked servlet request with pre-defined {@code content}, {@code type} and {@code headers}.
  *
- * <p>In most cases this implementation should be sufficient enough for local tests.
+ * @implNote The request is effectively immutable and does not pay attention to any
+ *         modification attempts. Such a mocked implementation may be used for tests where
+ *         we do not care if anything may be adjusted in the request while the request
+ *         is being processed.
  */
+@Immutable
 @SuppressWarnings("UnstableApiUsage") // we're OK using Guava's beta APIs
-public final class FixedContentRequest implements MockedRequest {
+public final class KnownRequest implements MockedRequest {
 
     private static final String CONTENT_TYPE = "Content-Type";
 
@@ -50,9 +55,9 @@ public final class FixedContentRequest implements MockedRequest {
     private final byte[] content;
     private final MediaType type;
 
-    private FixedContentRequest(ImmutableMap<String, String> headers,
-                                byte[] content,
-                                MediaType type) {
+    private KnownRequest(ImmutableMap<String, String> headers,
+                         byte[] content,
+                         MediaType type) {
         this.headers = headers;
         this.content = content;
         this.type = type;
@@ -62,7 +67,7 @@ private FixedContentRequest(ImmutableMap<String, String> headers,
      * Creates a new mocked request with specified {@code content} and default
      * {@linkplain MediaType#ANY_TYPE any} type.
      */
-    public static FixedContentRequest create(String content) {
+    public static KnownRequest create(String content) {
         checkNotNull(content);
         return create(content, MediaType.ANY_TYPE);
     }
@@ -70,7 +75,7 @@ public static FixedContentRequest create(String content) {
     /**
      * Creates a new mocked request with specified {@code content} and {@code type}.
      */
-    public static FixedContentRequest create(String content, MediaType type) {
+    public static KnownRequest create(String content, MediaType type) {
         checkNotNull(content);
         checkNotNull(type);
         return create(content, type, contentTypeHeader(type));
@@ -80,9 +85,9 @@ public static FixedContentRequest create(String content, MediaType type) {
      * Creates a new mocked request with specified {@code content}, {@code type}
      * and {@code headers}.
      */
-    public static FixedContentRequest create(String content,
-                                             MediaType type,
-                                             ImmutableMap<String, String> headers) {
+    public static KnownRequest create(String content,
+                                      MediaType type,
+                                      ImmutableMap<String, String> headers) {
         checkNotNull(content);
         checkNotNull(type);
         checkNotNull(headers);
@@ -93,13 +98,13 @@ public static FixedContentRequest create(String content,
      * Creates a new mocked request with specified {@code content}, {@code type}
      * and {@code headers}.
      */
-    public static FixedContentRequest create(byte[] content,
-                                             MediaType type,
-                                             ImmutableMap<String, String> headers) {
+    public static KnownRequest create(byte[] content,
+                                      MediaType type,
+                                      ImmutableMap<String, String> headers) {
         checkNotNull(content);
         checkNotNull(type);
         checkNotNull(headers);
-        return new FixedContentRequest(headers, content, type);
+        return new KnownRequest(headers, content, type);
     }
 
     private static ImmutableMap<String, String> contentTypeHeader(MediaType type) {
diff --git a/testutil-web/src/main/java/io/spine/web/given/FixedContentResponse.java b/testutil-web/src/main/java/io/spine/web/given/KnownResponse.java
similarity index 73%
rename from testutil-web/src/main/java/io/spine/web/given/FixedContentResponse.java
rename to testutil-web/src/main/java/io/spine/web/given/KnownResponse.java
index 87caae9bf..a1a93d35f 100644
--- a/testutil-web/src/main/java/io/spine/web/given/FixedContentResponse.java
+++ b/testutil-web/src/main/java/io/spine/web/given/KnownResponse.java
@@ -22,6 +22,7 @@
 
 import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.ImmutableSet;
+import com.google.errorprone.annotations.Immutable;
 import org.checkerframework.checker.nullness.qual.Nullable;
 
 import java.io.PrintWriter;
@@ -32,17 +33,22 @@
 /**
  * A mocked servlet response with pre-defined {@code writer}, {@code status} and {@code headers}.
  *
- * <p>In most cases this implementation should be sufficient enough for local tests.
+ * @implNote The response is effectively immutable and does not pay attention to any
+ *         modification attempts. Such a mocked implementation may be used for tests where
+ *         we do not care if anything may be adjusted in the response while the response
+ *         is being created.
+ *         See {@linkplain MemoizingResponse memoizing response} if mutability is required.
  */
-public final class FixedContentResponse implements MockedResponse {
+@Immutable
+public final class KnownResponse implements MockedResponse {
 
     private final ImmutableMap<String, String> headers;
     private final int status;
     private final Writer writer;
 
-    private FixedContentResponse(ImmutableMap<String, String> headers,
-                                 Writer writer,
-                                 int status) {
+    private KnownResponse(ImmutableMap<String, String> headers,
+                          Writer writer,
+                          int status) {
         this.headers = headers;
         this.writer = writer;
         this.status = status;
@@ -52,7 +58,7 @@ private FixedContentResponse(ImmutableMap<String, String> headers,
      * Creates a new mocked response with specified {@code writer} and default
      * {@linkplain #SC_OK OK} status.
      */
-    public static FixedContentResponse create(Writer writer) {
+    public static KnownResponse create(Writer writer) {
         checkNotNull(writer);
         return create(writer, SC_OK);
     }
@@ -60,7 +66,7 @@ public static FixedContentResponse create(Writer writer) {
     /**
      * Creates a new mocked response with specified {@code writer} and {@code status}.
      */
-    public static FixedContentResponse create(Writer writer, int status) {
+    public static KnownResponse create(Writer writer, int status) {
         checkNotNull(writer);
         return create(writer, status, ImmutableMap.of());
     }
@@ -69,12 +75,12 @@ public static FixedContentResponse create(Writer writer, int status) {
      * Creates a new mocked response with specified {@code writer}, {@code status}
      * and {@code headers}.
      */
-    public static FixedContentResponse create(Writer writer,
-                                              int status,
-                                              ImmutableMap<String, String> headers) {
+    public static KnownResponse create(Writer writer,
+                                       int status,
+                                       ImmutableMap<String, String> headers) {
         checkNotNull(writer);
         checkNotNull(headers);
-        return new FixedContentResponse(headers, writer, status);
+        return new KnownResponse(headers, writer, status);
     }
 
     @Override
diff --git a/testutil-web/src/main/java/io/spine/web/given/MemoizingResponse.java b/testutil-web/src/main/java/io/spine/web/given/MemoizingResponse.java
index d4c7e38f5..0372dcdcb 100644
--- a/testutil-web/src/main/java/io/spine/web/given/MemoizingResponse.java
+++ b/testutil-web/src/main/java/io/spine/web/given/MemoizingResponse.java
@@ -31,6 +31,11 @@
 
 /**
  * A mocked response that attempts to save all the actions done to it.
+ *
+ * @implNote The response mutates its state and holds the latest changes. Such an
+ *         implementation may be useful to verify that e.g. a particular error code was set
+ *         to the response or a particular content was written.
+ *         See {@linkplain KnownResponse known response} if an immutable implementation is required.
  */
 public final class MemoizingResponse implements MockedResponse {
 
diff --git a/testutil-web/src/test/java/io/spine/web/given/FixedContentRequestTest.java b/testutil-web/src/test/java/io/spine/web/given/KnownRequestTest.java
similarity index 91%
rename from testutil-web/src/test/java/io/spine/web/given/FixedContentRequestTest.java
rename to testutil-web/src/test/java/io/spine/web/given/KnownRequestTest.java
index 6ce16f3b4..fea3f3316 100644
--- a/testutil-web/src/test/java/io/spine/web/given/FixedContentRequestTest.java
+++ b/testutil-web/src/test/java/io/spine/web/given/KnownRequestTest.java
@@ -30,14 +30,14 @@
 
 import static com.google.common.truth.Truth.assertThat;
 
-@DisplayName("`FixedContentRequest` should")
-class FixedContentRequestTest {
+@DisplayName("`KnownRequest` should")
+class KnownRequestTest {
 
     @Test
     @DisplayName("not tolerate `null`s")
     void notTolerateNull() {
         NullPointerTester tester = new NullPointerTester();
-        tester.testAllPublicStaticMethods(FixedContentRequest.class);
+        tester.testAllPublicStaticMethods(KnownRequest.class);
     }
 
     @Test
@@ -49,7 +49,7 @@ void returnSetValues() throws IOException {
         String headerName = "custom";
         String headerValue = "header";
         ImmutableMap<String, String> headers = ImmutableMap.of(headerName, headerValue);
-        FixedContentRequest request = FixedContentRequest.create(text, type, headers);
+        KnownRequest request = KnownRequest.create(text, type, headers);
         assertThat(request.getContentLength())
                 .isEqualTo(text.length());
         assertThat(request.getContentLengthLong())
diff --git a/testutil-web/src/test/java/io/spine/web/given/FixedContentResponseTest.java b/testutil-web/src/test/java/io/spine/web/given/KnownResponseTest.java
similarity index 91%
rename from testutil-web/src/test/java/io/spine/web/given/FixedContentResponseTest.java
rename to testutil-web/src/test/java/io/spine/web/given/KnownResponseTest.java
index 3697f82d4..58f4c4f7b 100644
--- a/testutil-web/src/test/java/io/spine/web/given/FixedContentResponseTest.java
+++ b/testutil-web/src/test/java/io/spine/web/given/KnownResponseTest.java
@@ -32,14 +32,14 @@
 import static com.google.common.truth.Truth.assertThat;
 import static javax.servlet.http.HttpServletResponse.SC_ACCEPTED;
 
-@DisplayName("`FixedContentResponse` should")
-class FixedContentResponseTest {
+@DisplayName("`KnownResponse` should")
+class KnownResponseTest {
 
     @Test
     @DisplayName("not tolerate `null`s")
     void notTolerateNull() {
         NullPointerTester tester = new NullPointerTester();
-        tester.testAllPublicStaticMethods(FixedContentResponse.class);
+        tester.testAllPublicStaticMethods(KnownResponse.class);
     }
 
     @Test
@@ -50,7 +50,7 @@ void returnSetValues() {
         String headerValue = "header";
         ImmutableMap<String, String> headers = ImmutableMap.of(headerName, headerValue);
         StringWriter writer = new StringWriter();
-        FixedContentResponse response = FixedContentResponse.create(writer, SC_ACCEPTED, headers);
+        KnownResponse response = KnownResponse.create(writer, SC_ACCEPTED, headers);
         assertThat(response.getStatus())
                 .isEqualTo(SC_ACCEPTED);
         assertThat(response.getHeader(headerName))
diff --git a/web/src/test/java/io/spine/web/given/Servlets.java b/web/src/test/java/io/spine/web/given/Servlets.java
index 79e732c2d..00888e5ce 100644
--- a/web/src/test/java/io/spine/web/given/Servlets.java
+++ b/web/src/test/java/io/spine/web/given/Servlets.java
@@ -41,15 +41,15 @@ private Servlets() {
     /**
      * Creates a new request with the supplied {@code content}.
      */
-    public static FixedContentRequest request(Message content) {
+    public static KnownRequest request(Message content) {
         String json = Json.toJson(content);
-        return FixedContentRequest.create(json, MediaType.JSON_UTF_8);
+        return KnownRequest.create(json, MediaType.JSON_UTF_8);
     }
 
     /**
      * Creates a new response with the supplied {@code writer}.
      */
     public static HttpServletResponse response(StringWriter writer) {
-        return FixedContentResponse.create(writer);
+        return KnownResponse.create(writer);
     }
 }

From 5504b1d11abf253f51027f8256e285bf4484ae4f Mon Sep 17 00:00:00 2001
From: Yuri Sergiichuk <yuri.sergiichuk@teamdev.com>
Date: Mon, 7 Dec 2020 18:30:18 +0200
Subject: [PATCH 36/41] Improve naming and docs.

---
 .../firebase/rest/HttpClientMockFactory.java  | 20 +++++++++++++------
 1 file changed, 14 insertions(+), 6 deletions(-)

diff --git a/firebase-web/src/test/java/io/spine/web/firebase/rest/HttpClientMockFactory.java b/firebase-web/src/test/java/io/spine/web/firebase/rest/HttpClientMockFactory.java
index 2230db052..6be691f83 100644
--- a/firebase-web/src/test/java/io/spine/web/firebase/rest/HttpClientMockFactory.java
+++ b/firebase-web/src/test/java/io/spine/web/firebase/rest/HttpClientMockFactory.java
@@ -59,20 +59,23 @@ static HttpClient mockHttpClient(String content) {
     /**
      * Creates an {@code HttpClient} mock which returns the specified {@code content}
      * on every request and uses supplied {@code observer} while building requests.
+     *
+     * <p>The observer is called by the underlying {@code HttpRequestFactory} whenever a new
+     * HTTP request is being built.
      */
-    static HttpClient mockHttpClient(String content, RequestObserver observer) {
+    static HttpClient mockHttpClient(String content, HttpRequestObserver observer) {
         return HttpClient.using(mockRequestFactory(content, observer));
     }
 
     private static HttpRequestFactory
-    mockRequestFactory(String content, RequestObserver observer) {
+    mockRequestFactory(String content, HttpRequestObserver observer) {
         HttpTransport transportMock = mockHttpTransport(content, observer);
         HttpRequestFactory requestFactoryMock = transportMock.createRequestFactory();
         return requestFactoryMock;
     }
 
     private static HttpTransport
-    mockHttpTransport(String content, RequestObserver observer) {
+    mockHttpTransport(String content, HttpRequestObserver observer) {
         final MockLowLevelHttpResponse response = new MockLowLevelHttpResponse();
         response.setContent(content);
         return new MockHttpTransport() {
@@ -114,15 +117,20 @@ private static void noOpObserver(String method, String url) {
     }
 
     /**
-     * Observes built HTTP requests.
+     * An observer that is called by the underlying
+     * {@linkplain #mockHttpTransport(String, HttpRequestObserver) transport} whenever a request
+     * is being built.
+     *
+     * @implNote The observer allows the caller to sneak-peak into the request creation
+     *         process and verify that a particular request is being built.
      */
-    interface RequestObserver {
+    interface HttpRequestObserver {
 
         /**
          * A callback that is executed whenever an HTTP request is built.
          *
          * @param method
-         *         the HTTP method being used
+         *         the HTTP method being used to build a request
          * @param url
          *         the request URL
          */

From 356828301291e4e012d6c176f49186cbe444487a Mon Sep 17 00:00:00 2001
From: Yuri Sergiichuk <yuri.sergiichuk@teamdev.com>
Date: Mon, 7 Dec 2020 18:31:56 +0200
Subject: [PATCH 37/41] Cleanup the doc.

---
 .../src/main/java/io/spine/web/given/MockedRequest.java         | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/testutil-web/src/main/java/io/spine/web/given/MockedRequest.java b/testutil-web/src/main/java/io/spine/web/given/MockedRequest.java
index 87d21b0c3..333e46ee2 100644
--- a/testutil-web/src/main/java/io/spine/web/given/MockedRequest.java
+++ b/testutil-web/src/main/java/io/spine/web/given/MockedRequest.java
@@ -29,7 +29,7 @@
 import java.util.Map;
 
 /**
- * A mocked no-op servlet request that returns.
+ * A mocked no-op servlet request.
  *
  * @apiNote Some of the methods are marked as {@linkplain Deprecated deprecated} to avoid
  *         the deprecation warnings, as their {@code super} methods are marked as such.

From 446bdbb8a3392078f2fce3e966b9639ff9ecf580 Mon Sep 17 00:00:00 2001
From: Yuri Sergiichuk <yuri.sergiichuk@teamdev.com>
Date: Mon, 7 Dec 2020 18:33:53 +0200
Subject: [PATCH 38/41] Do not use `we` in the docs

---
 testutil-web/src/main/java/io/spine/web/given/KnownRequest.java | 2 +-
 .../src/main/java/io/spine/web/given/KnownResponse.java         | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/testutil-web/src/main/java/io/spine/web/given/KnownRequest.java b/testutil-web/src/main/java/io/spine/web/given/KnownRequest.java
index 7f3488eca..a58448bce 100644
--- a/testutil-web/src/main/java/io/spine/web/given/KnownRequest.java
+++ b/testutil-web/src/main/java/io/spine/web/given/KnownRequest.java
@@ -42,7 +42,7 @@
  *
  * @implNote The request is effectively immutable and does not pay attention to any
  *         modification attempts. Such a mocked implementation may be used for tests where
- *         we do not care if anything may be adjusted in the request while the request
+ *         one do not care if anything may be adjusted in the request while the request
  *         is being processed.
  */
 @Immutable
diff --git a/testutil-web/src/main/java/io/spine/web/given/KnownResponse.java b/testutil-web/src/main/java/io/spine/web/given/KnownResponse.java
index a1a93d35f..613c22fa5 100644
--- a/testutil-web/src/main/java/io/spine/web/given/KnownResponse.java
+++ b/testutil-web/src/main/java/io/spine/web/given/KnownResponse.java
@@ -35,7 +35,7 @@
  *
  * @implNote The response is effectively immutable and does not pay attention to any
  *         modification attempts. Such a mocked implementation may be used for tests where
- *         we do not care if anything may be adjusted in the response while the response
+ *         one do not care if anything may be adjusted in the response while the response
  *         is being created.
  *         See {@linkplain MemoizingResponse memoizing response} if mutability is required.
  */

From 38b734a4adee52dc9ae505ea92f5af2e4b5f4140 Mon Sep 17 00:00:00 2001
From: Yuri Sergiichuk <yuri.sergiichuk@teamdev.com>
Date: Mon, 7 Dec 2020 18:34:26 +0200
Subject: [PATCH 39/41] Improve formatting.

---
 .../src/main/java/io/spine/web/given/KnownRequest.java        | 4 +---
 .../src/main/java/io/spine/web/given/KnownResponse.java       | 4 +---
 2 files changed, 2 insertions(+), 6 deletions(-)

diff --git a/testutil-web/src/main/java/io/spine/web/given/KnownRequest.java b/testutil-web/src/main/java/io/spine/web/given/KnownRequest.java
index a58448bce..c8d1eb685 100644
--- a/testutil-web/src/main/java/io/spine/web/given/KnownRequest.java
+++ b/testutil-web/src/main/java/io/spine/web/given/KnownRequest.java
@@ -55,9 +55,7 @@ public final class KnownRequest implements MockedRequest {
     private final byte[] content;
     private final MediaType type;
 
-    private KnownRequest(ImmutableMap<String, String> headers,
-                         byte[] content,
-                         MediaType type) {
+    private KnownRequest(ImmutableMap<String, String> headers, byte[] content, MediaType type) {
         this.headers = headers;
         this.content = content;
         this.type = type;
diff --git a/testutil-web/src/main/java/io/spine/web/given/KnownResponse.java b/testutil-web/src/main/java/io/spine/web/given/KnownResponse.java
index 613c22fa5..44ba5e33f 100644
--- a/testutil-web/src/main/java/io/spine/web/given/KnownResponse.java
+++ b/testutil-web/src/main/java/io/spine/web/given/KnownResponse.java
@@ -46,9 +46,7 @@ public final class KnownResponse implements MockedResponse {
     private final int status;
     private final Writer writer;
 
-    private KnownResponse(ImmutableMap<String, String> headers,
-                          Writer writer,
-                          int status) {
+    private KnownResponse(ImmutableMap<String, String> headers, Writer writer, int status) {
         this.headers = headers;
         this.writer = writer;
         this.status = status;

From ad9b1ea63dea021e68e959ce47e83aca0d54bc10 Mon Sep 17 00:00:00 2001
From: Yuri Sergiichuk <yuri.sergiichuk@teamdev.com>
Date: Mon, 7 Dec 2020 18:35:52 +0200
Subject: [PATCH 40/41] Wrap `path` into `{@code }`.

---
 .../java/io/spine/web/firebase/given/MemoizingFirebase.java     | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/firebase-web/src/test/java/io/spine/web/firebase/given/MemoizingFirebase.java b/firebase-web/src/test/java/io/spine/web/firebase/given/MemoizingFirebase.java
index 206f8bbeb..68544e256 100644
--- a/firebase-web/src/test/java/io/spine/web/firebase/given/MemoizingFirebase.java
+++ b/firebase-web/src/test/java/io/spine/web/firebase/given/MemoizingFirebase.java
@@ -117,7 +117,7 @@ public ImmutableMap<NodePath, NodeValue> writes() {
      * Returns a {@code NodeValue} written to a specific {@code path}.
      *
      * @throws IllegalStateException
-     *         if no value is present for the path
+     *         if no value is present for the {@code path}
      */
     public NodeValue valueFor(NodePath path) {
         NodeValue result = writes.get(path);

From 7d30d92c4adb852d41bbea43fe64acef294b5783 Mon Sep 17 00:00:00 2001
From: Yuri Sergiichuk <yuri.sergiichuk@teamdev.com>
Date: Mon, 7 Dec 2020 18:40:04 +0200
Subject: [PATCH 41/41] Do not use `@Immutable annotation`.

---
 testutil-web/src/main/java/io/spine/web/given/KnownRequest.java | 2 --
 .../src/main/java/io/spine/web/given/KnownResponse.java         | 2 --
 2 files changed, 4 deletions(-)

diff --git a/testutil-web/src/main/java/io/spine/web/given/KnownRequest.java b/testutil-web/src/main/java/io/spine/web/given/KnownRequest.java
index c8d1eb685..a42182c77 100644
--- a/testutil-web/src/main/java/io/spine/web/given/KnownRequest.java
+++ b/testutil-web/src/main/java/io/spine/web/given/KnownRequest.java
@@ -23,7 +23,6 @@
 import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.ImmutableSet;
 import com.google.common.net.MediaType;
-import com.google.errorprone.annotations.Immutable;
 import org.checkerframework.checker.nullness.qual.Nullable;
 
 import java.io.BufferedReader;
@@ -45,7 +44,6 @@
  *         one do not care if anything may be adjusted in the request while the request
  *         is being processed.
  */
-@Immutable
 @SuppressWarnings("UnstableApiUsage") // we're OK using Guava's beta APIs
 public final class KnownRequest implements MockedRequest {
 
diff --git a/testutil-web/src/main/java/io/spine/web/given/KnownResponse.java b/testutil-web/src/main/java/io/spine/web/given/KnownResponse.java
index 44ba5e33f..1d2b56126 100644
--- a/testutil-web/src/main/java/io/spine/web/given/KnownResponse.java
+++ b/testutil-web/src/main/java/io/spine/web/given/KnownResponse.java
@@ -22,7 +22,6 @@
 
 import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.ImmutableSet;
-import com.google.errorprone.annotations.Immutable;
 import org.checkerframework.checker.nullness.qual.Nullable;
 
 import java.io.PrintWriter;
@@ -39,7 +38,6 @@
  *         is being created.
  *         See {@linkplain MemoizingResponse memoizing response} if mutability is required.
  */
-@Immutable
 public final class KnownResponse implements MockedResponse {
 
     private final ImmutableMap<String, String> headers;