From 52c504e20aaa2381abd5d87968c2863f8e85f288 Mon Sep 17 00:00:00 2001
From: Oleksandr Vayda <oleksandr.vayda@gmail.com>
Date: Wed, 27 Jan 2021 23:36:11 +0100
Subject: [PATCH] commons #54 Configuration utils: EnvironmentConfiguration
 extension to support UPPER_SNAKE_CASE for environment variables

---
 ...perSnakeCaseEnvironmentConfiguration.scala | 38 ++++++++++++
 ...nakeCaseEnvironmentConfigurationSpec.scala | 58 +++++++++++++++++++
 2 files changed, 96 insertions(+)
 create mode 100644 src/main/scala/za/co/absa/commons/config/UpperSnakeCaseEnvironmentConfiguration.scala
 create mode 100644 src/test/scala/za/co/absa/commons/config/UpperSnakeCaseEnvironmentConfigurationSpec.scala

diff --git a/src/main/scala/za/co/absa/commons/config/UpperSnakeCaseEnvironmentConfiguration.scala b/src/main/scala/za/co/absa/commons/config/UpperSnakeCaseEnvironmentConfiguration.scala
new file mode 100644
index 0000000..63ba292
--- /dev/null
+++ b/src/main/scala/za/co/absa/commons/config/UpperSnakeCaseEnvironmentConfiguration.scala
@@ -0,0 +1,38 @@
+/*
+ * Copyright 2021 ABSA Group Limited
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package za.co.absa.commons.config
+
+import org.apache.commons.configuration.EnvironmentConfiguration
+import org.apache.commons.lang.StringUtils
+import za.co.absa.commons.config.UpperSnakeCaseEnvironmentConfiguration.toUpperSnake
+
+class UpperSnakeCaseEnvironmentConfiguration extends EnvironmentConfiguration {
+
+  override def getProperty(key: String): AnyRef = super.getProperty(toUpperSnake(key))
+
+  override def containsKey(key: String): Boolean = super.containsKey(toUpperSnake(key))
+}
+
+object UpperSnakeCaseEnvironmentConfiguration {
+  private def toUpperSnake(key: String) = {
+    key
+      .split("[\\W_]")
+      .flatMap(StringUtils.splitByCharacterTypeCamelCase)
+      .map(_.toUpperCase)
+      .mkString("_")
+  }
+}
diff --git a/src/test/scala/za/co/absa/commons/config/UpperSnakeCaseEnvironmentConfigurationSpec.scala b/src/test/scala/za/co/absa/commons/config/UpperSnakeCaseEnvironmentConfigurationSpec.scala
new file mode 100644
index 0000000..967b6c9
--- /dev/null
+++ b/src/test/scala/za/co/absa/commons/config/UpperSnakeCaseEnvironmentConfigurationSpec.scala
@@ -0,0 +1,58 @@
+/*
+ * Copyright 2021 ABSA Group Limited
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package za.co.absa.commons.config
+
+import org.scalatest.flatspec.AnyFlatSpec
+import org.scalatest.matchers.should.Matchers
+import za.co.absa.commons.scalatest.EnvFixture
+
+class UpperSnakeCaseEnvironmentConfigurationSpec
+  extends AnyFlatSpec
+    with Matchers
+    with EnvFixture {
+
+  it should "act as normal when given a key in format 'MY_VAR_NAME'" in {
+    setEnv("FOO_BAR_BAZ_42_QUX", "right")
+    (new UpperSnakeCaseEnvironmentConfiguration).containsKey("FOO_BAR_BAZ_42_QUX") should be(true)
+    (new UpperSnakeCaseEnvironmentConfiguration).getString("FOO_BAR_BAZ_42_QUX") should equal("right")
+  }
+
+  it should "ignore lower-case keys" in {
+    setEnv("foo.barBaz42.Qux", "wrong")
+    (new UpperSnakeCaseEnvironmentConfiguration).containsKey("foo.barBaz42.Qux") should be(false)
+    (new UpperSnakeCaseEnvironmentConfiguration).getString("foo.barBaz42.Qux") should be(null)
+  }
+
+  it should "convert keys per the environment variable naming convention, i.e 'my.varName' to 'MY_VAR_NAME'" in {
+    setEnv("FOO_BAR_BAZ_42_QUX", "right")
+    (new UpperSnakeCaseEnvironmentConfiguration).containsKey("foo.barBaz42.Qux") should be(true)
+    (new UpperSnakeCaseEnvironmentConfiguration).getString("foo.barBaz42.Qux") should equal("right")
+  }
+
+  it should "fix issue Spline-616" in {
+    setEnv("SPLINE_DATABASE_CONNECTION_URL", "right")
+    (new UpperSnakeCaseEnvironmentConfiguration).containsKey("spline.database.connectionUrl") should be(true)
+    (new UpperSnakeCaseEnvironmentConfiguration).getString("spline.database.connectionUrl") should equal("right")
+  }
+
+  it should "return null if non of the keys found" in {
+    (new UpperSnakeCaseEnvironmentConfiguration).containsKey("foo.barBaz42.Qux") should be(false)
+    (new UpperSnakeCaseEnvironmentConfiguration).getString("foo.barBaz42.Qux") should be(null)
+  }
+
+}
+