inline: expand expression lambda to code block for return-inline (IDEA-180888)

java/java-impl/src/com/intellij/refactoring/util/InlineUtil.java

@@ -314,9 +314,12 @@ public class InlineUtil {
     if (element instanceof PsiMethodReferenceExpression) return TailCallType.None;
     PsiExpression methodCall = PsiTreeUtil.getParentOfType(element, PsiMethodCallExpression.class);
     if (methodCall == null) return TailCallType.None;
-    if (methodCall.getParent() instanceof PsiReturnStatement) return TailCallType.Return;
-    if (methodCall.getParent() instanceof PsiExpressionStatement) {
-      PsiStatement callStatement = (PsiStatement) methodCall.getParent();
+    PsiElement callParent = methodCall.getParent();
+    if (callParent instanceof PsiReturnStatement || callParent instanceof PsiLambdaExpression) {
+      return TailCallType.Return;
+    }
+    if (callParent instanceof PsiExpressionStatement) {
+      PsiStatement callStatement = (PsiStatement)callParent;
       PsiMethod callerMethod = PsiTreeUtil.getParentOfType(callStatement, PsiMethod.class);
       if (callerMethod != null) {
         final PsiStatement[] psiStatements = callerMethod.getBody().getStatements();

java/java-tests/testData/refactoring/inlineMethod/ExprLambdaExpandToCodeBlock.java

@@ -0,0 +1,16 @@
+
+import java.util.Comparator;
+
+class InlineLambda {
+    private static int compare(Integer i, Integer j) {
+        if (i > j) {
+            return 1;
+        }
+        if (j > i) {
+            return -1;
+        }
+        return 0;
+    }
+
+    private static Comparator<Integer> COMP = (o1, o2) -> com<caret>pare(o1, o2);
+}

java/java-tests/testData/refactoring/inlineMethod/ExprLambdaExpandToCodeBlock.java.after

@@ -0,0 +1,24 @@
+
+import java.util.Comparator;
+
+class InlineLambda {
+    private static int compare(Integer i, Integer j) {
+        if (i > j) {
+            return 1;
+        }
+        if (j > i) {
+            return -1;
+        }
+        return 0;
+    }
+
+    private static Comparator<Integer> COMP = (o1, o2) -> {
+        if (o1 > o2) {
+            return 1;
+        }
+        if (o2 > o1) {
+            return -1;
+        }
+        return 0;
+    };
+}

java/java-tests/testSrc/com/intellij/java/refactoring/inline/InlineMethodTest.java

@@ -339,6 +339,10 @@ public class InlineMethodTest extends LightRefactoringTestCase {
     doTestConflict("Constructor <b><code>SomeClass.SomeClass()</code></b> that is used in inlined method is not accessible from call site(s) in method <b><code>InlineWithPrivateConstructorAccessMain.main(String...)</code></b>");
   }
 
+  public void testExprLambdaExpandToCodeBlock() {
+    doTestInlineThisOnly();
+  }
+
   public void testSuperCallWhenUnqualifiedInline() {
     doTestInlineThisOnly();
   }