introduce functional variable: allow comments (IDEA-174183)

java/java-impl/src/com/intellij/refactoring/introduceVariable/IntroduceFunctionalVariableHandler.java

@@ -60,7 +60,7 @@ public class IntroduceFunctionalVariableHandler extends IntroduceVariableHandler
           showErrorMessage(project , editor, message);
           return;
         }
-        PsiElement anchorStatement = RefactoringUtil.getParentStatement(elements[0], false);
+        PsiElement anchorStatement = elements[0] instanceof PsiComment ? elements[0] : RefactoringUtil.getParentStatement(elements[0], false);
         PsiElement tempContainer = checkAnchorStatement(project, editor, anchorStatement);
         if (tempContainer == null) return;
 

java/java-tests/testData/refactoring/introduceFunctionalVariable/afterRunnableFromComment.java

@@ -0,0 +1,8 @@
+class Test {
+    {
+        Runnable runnable = () -> {
+            //my comment
+        };
+        runnable.run();
+    }
+}

java/java-tests/testData/refactoring/introduceFunctionalVariable/beforeRunnableFromComment.java

@@ -0,0 +1,5 @@
+class Test {
+    {
+        <selection>//my comment</selection>
+    }
+}

java/java-tests/testSrc/com/intellij/java/refactoring/IntroduceFunctionalVariableTest.java

@@ -63,6 +63,10 @@ public class IntroduceFunctionalVariableTest extends LightRefactoringTestCase  {
     doTest(0);
   }
 
+  public void testRunnableFromComment() throws Exception {
+    doTest();
+  }
+
   public void testIgnoreMethodObjectSuggestion() throws Exception {
     try {
       doTest();