Add test suite for the using() routine.

Author: yruslan

cobol-parser/src/main/scala/za/co/absa/cobrix/cobol/utils/AutoCloseableSpy.scala

@@ -0,0 +1,40 @@
+/*
+ * Copyright 2018 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.cobrix.cobol.utils
+
+class AutoCloseableSpy(failCreate: Boolean = false, failAction: Boolean = false, failClose: Boolean = false) extends AutoCloseable {
+  var actionCallCount: Int = 0
+  var closeCallCount: Int = 0
+
+  if (failCreate) {
+    throw new RuntimeException("Failed to create resource")
+  }
+
+  def dummyAction(): Unit = {
+    actionCallCount += 1
+    if (failAction) {
+      throw new RuntimeException("Failed during action")
+    }
+  }
+
+  override def close(): Unit = {
+    closeCallCount += 1
+    if (failClose) {
+      throw new RuntimeException("Failed to close resource")
+    }
+  }
+}

cobol-parser/src/test/scala/za/co/absa/cobrix/cobol/utils/UsingUtilsSuite.scala

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+/*
+ * Copyright 2018 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.cobrix.cobol.utils
+
+import org.scalatest.wordspec.AnyWordSpec
+
+class UsingUtilsSuite extends AnyWordSpec {
+  "using with a single resource" should {
+    "properly close the resource" in {
+      var resource: AutoCloseableSpy = null
+
+      UsingUtils.using(new AutoCloseableSpy()) { res =>
+        resource = res
+        res.dummyAction()
+      }
+
+      assert(resource.actionCallCount == 1)
+      assert(resource.closeCallCount == 1)
+    }
+
+    "close resource even if exception occurs" in {
+      var resource: AutoCloseableSpy = null
+      var exceptionThrown = false
+
+      try {
+        UsingUtils.using(new AutoCloseableSpy(failAction = true)) { res =>
+          resource = res
+          res.dummyAction()
+        }
+      } catch {
+        case ex: Throwable =>
+          assert(ex.getMessage.contains("Failed during action"))
+          exceptionThrown = true
+      }
+
+      assert(exceptionThrown)
+      assert(resource.actionCallCount == 1)
+      assert(resource.closeCallCount == 1)
+    }
+
+    "handle exceptions when a resource is created" in {
+      var exceptionThrown = false
+      var resource: AutoCloseableSpy = null
+
+      try {
+        UsingUtils.using(new AutoCloseableSpy(failCreate = true)) { res =>
+          resource = res
+          res.dummyAction()
+        }
+      } catch {
+        case ex: Throwable =>
+          exceptionThrown = true
+          assert(ex.getMessage.contains("Failed to create resource"))
+      }
+
+      assert(exceptionThrown)
+      assert(resource == null)
+    }
+
+    "handle exceptions when a resource is closed" in {
+      var resource: AutoCloseableSpy = null
+      var exceptionThrown = false
+
+      try {
+        UsingUtils.using(new AutoCloseableSpy(failClose = true)) { res =>
+          resource = res
+          res.dummyAction()
+        }
+      } catch {
+        case ex: Throwable =>
+          exceptionThrown = true
+          assert(ex.getMessage.contains("Failed to close resource"))
+      }
+
+      assert(exceptionThrown)
+      assert(resource.actionCallCount == 1)
+      assert(resource.closeCallCount == 1)
+    }
+
+    "handle exceptions on both action and close" in {
+      var resource: AutoCloseableSpy = null
+      var exceptionThrown = false
+
+      try {
+        UsingUtils.using(new AutoCloseableSpy(failClose = true)) { res =>
+          resource = res
+          res.dummyAction()
+          throw new RuntimeException("Failed during action")
+        }
+      } catch {
+        case ex: Throwable =>
+          exceptionThrown = true
+          assert(ex.getMessage.contains("Failed during action"))
+          val suppressed = ex.getSuppressed
+          assert(suppressed.length == 1)
+          assert(suppressed(0).getMessage.contains("Failed to close resource"))
+      }
+
+      assert(exceptionThrown)
+      assert(resource.actionCallCount == 1)
+      assert(resource.closeCallCount == 1)
+    }
+  }
+
+  "using with two resources" should {
+    "properly close both resources" in {
+      var resource1: AutoCloseableSpy = null
+      var resource2: AutoCloseableSpy = null
+
+      val result = UsingUtils.using(new AutoCloseableSpy()) { res1 =>
+        resource1 = res1
+        UsingUtils.using(new AutoCloseableSpy()) { res2 =>
+          resource2 = res2
+          res1.dummyAction()
+          res2.dummyAction()
+          100
+        }
+      }
+
+      assert(result == 100)
+      assert(resource1.actionCallCount == 1)
+      assert(resource1.closeCallCount == 1)
+      assert(resource2.actionCallCount == 1)
+      assert(resource2.closeCallCount == 1)
+    }
+
+    "properly close both resources when an inner one throws an exception during action and close" in {
+      var resource1: AutoCloseableSpy = null
+      var resource2: AutoCloseableSpy = null
+      var exceptionThrown = false
+
+      try {
+        UsingUtils.using(new AutoCloseableSpy()) { res1 =>
+          resource1 = res1
+          UsingUtils.using(new AutoCloseableSpy(failAction = true, failClose = true)) { res2 =>
+            resource2 = res2
+            res1.dummyAction()
+            res2.dummyAction()
+          }
+        }
+      } catch {
+        case ex: Throwable =>
+          exceptionThrown = true
+          assert(ex.getMessage.contains("Failed during action"))
+          val suppressed = ex.getSuppressed
+          assert(suppressed.length == 1)
+          assert(suppressed(0).getMessage.contains("Failed to close resource"))
+      }
+
+      assert(exceptionThrown)
+      assert(resource1.actionCallCount == 1)
+      assert(resource1.closeCallCount == 1)
+      assert(resource2.actionCallCount == 1)
+      assert(resource2.closeCallCount == 1)
+    }
+
+    "properly close both resources when an outer one throws an exception during action and close" in {
+      var resource1: AutoCloseableSpy = null
+      var resource2: AutoCloseableSpy = null
+      var exceptionThrown = false
+
+      try {
+        UsingUtils.using(new AutoCloseableSpy(failAction = true, failClose = true)) { res1 =>
+          resource1 = res1
+          UsingUtils.using(new AutoCloseableSpy()) { res2 =>
+            resource2 = res2
+            res1.dummyAction()
+            res2.dummyAction()
+          }
+        }
+      } catch {
+        case ex: Throwable =>
+          exceptionThrown = true
+          assert(ex.getMessage.contains("Failed during action"))
+          val suppressed = ex.getSuppressed
+          assert(suppressed.length == 1)
+          assert(suppressed(0).getMessage.contains("Failed to close resource"))
+      }
+
+      assert(exceptionThrown)
+      assert(resource1.actionCallCount == 1)
+      assert(resource1.closeCallCount == 1)
+      assert(resource2.actionCallCount == 0)
+      assert(resource2.closeCallCount == 1)
+    }
+
+    "properly close the outer resource when the inner one fails on create" in {
+      var resource1: AutoCloseableSpy = null
+      var resource2: AutoCloseableSpy = null
+      var exceptionThrown = false
+
+      try {
+        UsingUtils.using(new AutoCloseableSpy()) { res1 =>
+          resource1 = res1
+          UsingUtils.using(new AutoCloseableSpy(failCreate = true)) { res2 =>
+            resource2 = res2
+            res1.dummyAction()
+            res2.dummyAction()
+          }
+        }
+      } catch {
+        case ex: Throwable =>
+          exceptionThrown = true
+          assert(ex.getMessage.contains("Failed to create resource"))
+      }
+
+      assert(exceptionThrown)
+      assert(resource1.actionCallCount == 0)
+      assert(resource1.closeCallCount == 1)
+      assert(resource2 == null)
+    }
+  }
+}