WrapRule to simplify test rule writing (since we use Kotlin)

lib/annotations/junit4/org/junit/rules/annotations.xml

@@ -11,6 +11,14 @@
   <item name='org.junit.rules.TestRule org.junit.runners.model.Statement apply(org.junit.runners.model.Statement, org.junit.runner.Description)'>
     <annotation name='org.jetbrains.annotations.NotNull'/>
   </item>
+  <item
+    name='org.junit.rules.TestRule org.junit.runners.model.Statement apply(org.junit.runners.model.Statement, org.junit.runner.Description) 0'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
+  <item
+    name='org.junit.rules.TestRule org.junit.runners.model.Statement apply(org.junit.runners.model.Statement, org.junit.runner.Description) 1'>
+    <annotation name='org.jetbrains.annotations.NotNull'/>
+  </item>
   <item name='org.junit.rules.TestWatcher void finished(org.junit.runner.Description) 0'>
     <annotation name='org.jetbrains.annotations.NotNull'/>
   </item>

platform/configuration-store-impl/testSrc/DefaultProjectStoreTest.kt

@@ -8,15 +8,11 @@ import com.intellij.openapi.components.StoragePathMacros
 import com.intellij.openapi.components.service
 import com.intellij.openapi.components.stateStore
 import com.intellij.openapi.project.ProjectManager
-import com.intellij.testFramework.ProjectRule
-import com.intellij.testFramework.RuleChain
-import com.intellij.testFramework.TemporaryDirectory
-import com.intellij.testFramework.deleteRecursively
+import com.intellij.testFramework.*
 import org.assertj.core.api.Assertions.assertThat
 import org.junit.ClassRule
 import org.junit.Rule
 import org.junit.Test
-import org.junit.rules.ExternalResource
 import java.nio.file.Paths
 
 internal class DefaultProjectStoreTest {
@@ -30,17 +26,11 @@ internal class DefaultProjectStoreTest {
 
   private val ruleChain = RuleChain(
     tempDirManager,
-    object : ExternalResource() {
-      private var isDoNotSave = false
-
-      override fun before() {
-        val app = ApplicationManagerEx.getApplicationEx()
-        isDoNotSave = app.isDoNotSave
-        app.doNotSave(false)
-      }
-
-      override fun after() {
-        val app = ApplicationManagerEx.getApplicationEx()
+    WrapRule {
+      val app = ApplicationManagerEx.getApplicationEx()
+      val isDoNotSave = app.isDoNotSave
+      app.doNotSave(false);
+      {
         try {
           app.doNotSave(isDoNotSave)
         }
@@ -49,17 +39,11 @@ internal class DefaultProjectStoreTest {
         }
       }
     },
-    object : ExternalResource() {
-      private var externalDependenciesManager: ExternalDependenciesManager? = null
-
-      override fun before() {
-        val defaultProject = ProjectManager.getInstance().defaultProject
-        externalDependenciesManager = defaultProject.service<ExternalDependenciesManager>()
-        externalDependenciesManager!!.allDependencies = requiredPlugins
-      }
-
-      override fun after() {
-        externalDependenciesManager?.allDependencies = emptyList()
+    WrapRule {
+      val externalDependenciesManager = ProjectManager.getInstance().defaultProject.service<ExternalDependenciesManager>()
+      externalDependenciesManager.allDependencies = requiredPlugins
+      {
+        externalDependenciesManager.allDependencies = emptyList()
       }
     }
   )

platform/testFramework/test-framework-java8/FixtureRule.kt

@@ -245,7 +245,7 @@ class DisposeModulesRule(private val projectRule: ProjectRule) : ExternalResourc
           try {
             moduleManager.disposeModule(module)
           }
-          catch(e: Throwable) {
+          catch (e: Throwable) {
             if (errors == null) {
               errors = SmartList()
             }
@@ -256,4 +256,24 @@ class DisposeModulesRule(private val projectRule: ProjectRule) : ExternalResourc
       CompoundRuntimeException.throwIfNotEmpty(errors)
     }
   }
-}
+}
+
+/**
+ * Only and only if "before" logic in case of exception doesn't require "after" logic - must be no side effects if "before" finished abnormally.
+ * So, should be one task per rule.
+ */
+class WrapRule(private val before: () -> () -> Unit) : TestRule {
+  override final fun apply(base: Statement, description: Description): Statement {
+    return object : Statement() {
+      override fun evaluate() {
+        val after = before()
+        try {
+          base.evaluate()
+        }
+        finally {
+          after()
+        }
+      }
+    }
+  }
+}