safe delete: warn about functional expressions

java/java-tests/testData/refactoring/safeDelete/FunctionalInterfaceMethod.java

@@ -0,0 +1,11 @@
+interface SAM {
+  void fo<caret>o(int i);
+}
+
+class Test {
+
+  {
+    SAM sam = (i) -> {};
+  }
+
+}

java/java-tests/testData/refactoring/safeDelete/ParameterFromFunctionalInterface.java

@@ -0,0 +1,11 @@
+interface SAM {
+  void foo(int <caret>i);
+}
+
+class Test {
+
+  {
+    SAM sam = (i) -> {};
+  }
+
+}

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

@@ -134,6 +134,30 @@ public class SafeDeleteTest extends MultiFileTestCase {
     }
   }
 
+  public void testParameterFromFunctionalInterface() throws Exception {
+    try {
+      LanguageLevelProjectExtension.getInstance(getProject()).setLanguageLevel(LanguageLevel.JDK_1_8);
+      doSingleFileTest();
+      fail("Conflict was not detected");
+    }
+    catch (BaseRefactoringProcessor.ConflictsInTestsException e) {
+      String message = e.getMessage();
+      assertEquals("class <b><code>SAM</code></b> has 1 usage that is not safe to delete.", message);
+    }
+  }
+
+  public void testFunctionalInterfaceMethod() throws Exception {
+    try {
+      LanguageLevelProjectExtension.getInstance(getProject()).setLanguageLevel(LanguageLevel.JDK_1_8);
+      doSingleFileTest();
+      fail("Conflict was not detected");
+    }
+    catch (BaseRefactoringProcessor.ConflictsInTestsException e) {
+      String message = e.getMessage();
+      assertEquals("class <b><code>SAM</code></b> has 1 usage that is not safe to delete.", message);
+    }
+  }
+
   public void testMethodDeepHierarchy() throws Exception {
     doTest("Super");
   }