inline method: allow lambda inlining (IDEA-177994)

java/java-impl/src/com/intellij/refactoring/inline/InlineMethodProcessor.java

@@ -1086,7 +1086,7 @@ public class InlineMethodProcessor extends BaseRefactoringProcessor {
       initializer.accept(canAllLocalsBeDeclaredFinal);
       if (!canAllLocalsBeDeclaredFinal.success) return false;
     }
-    if (initializer instanceof PsiMethodReferenceExpression) return true;
+    if (initializer instanceof PsiFunctionalExpression) return accessCount <= 1;
     if (initializer instanceof PsiReferenceExpression) {
       PsiVariable refVar = (PsiVariable)((PsiReferenceExpression)initializer).resolve();
       if (refVar == null) {

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

@@ -0,0 +1,9 @@
+class Foo {
+    void m(Runnable r) {}
+    void ff(Runnable r) {
+        m(r);
+    }
+    {
+        f<caret>f(() -> {});
+    }
+}

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

@@ -0,0 +1,9 @@
+class Foo {
+    void m(Runnable r) {}
+    void ff(Runnable r) {
+        m(r);
+    }
+    {
+        m(() -> {});
+    }
+}

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

@@ -275,6 +275,10 @@ public class InlineMethodTest extends LightRefactoringTestCase {
     doTestInlineThisOnly();
   }
 
+  public void testOnLambda() {
+    doTestInlineThisOnly();
+  }
+
   public void testNonCodeUsage() {
     doTest(true);
   }