Fix broken & unnecessary reflection

Author: sofurihafe

utbot-framework/src/main/kotlin/org/utbot/framework/codegen/domain/builtin/MockitoBuiltins.kt

@@ -97,7 +97,8 @@ internal val doNothingMethodId = builtinStaticMethodId(
 internal val whenStubberMethodId = builtinMethodId(
     classId = stubberClassId,
     name = "when",
-    returnType = objectClassId,
+    returnType = stubberClassId,
+    arguments = arrayOf(objectClassId)
 )
 
 // TODO: for this method and other static methods implement some utils that allow calling

utbot-framework/src/main/kotlin/org/utbot/framework/codegen/services/access/CgCallableAccessManager.kt

@@ -10,6 +10,7 @@ import org.utbot.framework.codegen.domain.builtin.getTargetException
 import org.utbot.framework.codegen.domain.builtin.invoke
 import org.utbot.framework.codegen.domain.builtin.newInstance
 import org.utbot.framework.codegen.domain.builtin.setAccessible
+import org.utbot.framework.codegen.domain.builtin.stubberClassId
 import org.utbot.framework.codegen.domain.context.CgContext
 import org.utbot.framework.codegen.domain.context.CgContextOwner
 import org.utbot.framework.codegen.domain.models.CgAllocateArray
@@ -192,8 +193,16 @@ internal class CgCallableAccessManagerImpl(val context: CgContext) : CgCallableA
         when {
             // method of the current test class can be called on its 'this' instance
             currentTestClass == executable.classId && this isThisInstanceOf currentTestClass -> true
+
             // method of a class can be called on an object of this class or any of its subtypes
             this.type isSubtypeOf executable.classId -> true
+
+            // We allow callers with [stubberClassId] classId to call any executable.
+            // Example to see why: doNothing().when(entityManagerMock).persist(any()).
+            // Here [persist()] cannot be called on [doNothing().when(entityManagerMock)],
+            // because it requires [EntityManager] classId caller.
+            this.type == stubberClassId -> true
+
             else -> false
         }
 

utbot-framework/src/main/kotlin/org/utbot/framework/codegen/services/framework/MockFrameworkManager.kt

@@ -202,6 +202,8 @@ private class MockitoMocker(context: CgContext) : ObjectMocker(context) {
                     // We would like to mark that this field is used and must not be removed from test class.
                     // Without `doNothing` call Intellij Idea suggests removing this field as unused.
                     is MethodId -> {
+                        // We allow [stubberClassId] to be a receiver of [executable].
+                        // See [CgExpression.canBeReceiverOf]
                         +mockitoClassId[doNothingMethodId]()[whenStubberMethodId](mockObject)[executable](*matchers)
                     }
                     else -> error("Only MethodId and ConstructorId was expected to appear in simple mocker but got $executable")