functional expressions: allow to delete/change signature of default methods of functional interfaces

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/lambda/changeSignature/DefaultMethodTouched.java

@@ -0,0 +1,12 @@
+interface SAM {
+  default void <caret>foo(){}
+  void bar();
+}
+
+class Test {
+  {
+    bar(() -> {});
+  }
+  
+  void bar(SAM sam){}
+}

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/lambda/changeSignature/DefaultMethodTouched_after.java

@@ -0,0 +1,12 @@
+interface SAM {
+  default void foo(boolean b){}
+  void bar();
+}
+
+class Test {
+  {
+    bar(() -> {});
+  }
+  
+  void bar(SAM sam){}
+}

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

@@ -0,0 +1,12 @@
+interface SAM {
+  default void fo<caret>o(int i){}
+  void bar(int i);
+}
+
+class Test {
+
+  {
+    SAM sam = (i) -> {};
+  }
+
+}

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

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

java/java-tests/testSrc/com/intellij/codeInsight/daemon/lambda/ChangeSignatureTouchLambdaTest.java

@@ -31,6 +31,10 @@ public class ChangeSignatureTouchLambdaTest extends ChangeSignatureBaseTest {
     doTestConflict();
   }
 
+  public void testDefaultMethodTouched() throws Exception {
+    doTest(null, null, null, new ParameterInfoImpl[] {new ParameterInfoImpl(-1, "b", PsiType.BOOLEAN)}, new ThrownExceptionInfo[0], false);
+  }
+
   private void doTestConflict() {
     try {
       doTest(null, null, null, new ParameterInfoImpl[] {new ParameterInfoImpl(-1, "b", PsiType.BOOLEAN)}, new ThrownExceptionInfo[0], false);

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

@@ -158,6 +158,11 @@ public class SafeDeleteTest extends MultiFileTestCase {
     }
   }
 
+  public void testFunctionalInterfaceDefaultMethod() throws Exception {
+    LanguageLevelProjectExtension.getInstance(getProject()).setLanguageLevel(LanguageLevel.JDK_1_8);
+    doSingleFileTest();
+  }
+
   public void testMethodDeepHierarchy() throws Exception {
     doTest("Super");
   }