Fix return type checking for generator functions.

pkg/analyzer/test/generated/non_error_resolver_test.dart

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library engine.non_error_resolver_test;
 
 import 'package:analyzer/src/generated/ast.dart';
 import 'package:analyzer/src/generated/element.dart';
 import 'package:analyzer/src/generated/error.dart';
 import 'package:analyzer/src/generated/parser.dart' show ParserErrorCode;
@@ skipping 1262 matching lines @@
   void test_dynamicIdentifier() {
     Source source = addSource(r'''
 main() {
   var v = dynamic;
 }''');
     resolve(source);
     assertNoErrors(source);
     verify([source]);
   }
 
+  void test_empty_generator_async() {
+    Source source = addSource('''
+import 'dart:async';
+Stream<int> f() async* {
+}
+''');
+    resolve(source);
+    assertNoErrors(source);
+    verify([source]);
+  }
+
+  void test_empty_generator_sync() {
+    Source source = addSource('''
+Iterable<int> f() sync* {
+}
+''');
+    resolve(source);
+    assertNoErrors(source);
+    verify([source]);
+  }
+
   void test_expectedOneListTypeArgument() {
     Source source = addSource(r'''
 main() {
   <int> [];
 }''');
     resolve(source);
     assertNoErrors(source);
     verify([source]);
   }
 
@@ skipping 20 matching lines @@
   void test_exportOfNonLibrary_libraryNotDeclared() {
     Source source = addSource(r'''
 library L;
 export 'lib1.dart';''');
     addNamedSource("/lib1.dart", "");
     resolve(source);
     assertNoErrors(source);
     verify([source]);
   }
 
+  void test_extraPositionalArguments_Function() {
+    Source source = addSource(r'''
+f(Function a) {
+  a(1, 2);
+}''');
+    resolve(source);
+    assertNoErrors(source);
+    verify([source]);
+  }
+
   void test_extraPositionalArguments_function() {
     Source source = addSource(r'''
 f(p1, p2) {}
 main() {
   f(1, 2);
 }''');
     resolve(source);
     assertNoErrors(source);
-    verify([source]);
-  }
-
-  void test_extraPositionalArguments_Function() {
-    Source source = addSource(r'''
-f(Function a) {
-  a(1, 2);
-}''');
-    resolve(source);
-    assertNoErrors(source);
     verify([source]);
   }
 
   void test_extraPositionalArguments_implicitConstructor() {
     Source source = addSource(r'''
 class A<E extends num> {
   A(E x, E y);
 }
 class M {}
 class B<E extends num> = A<E> with M;
@@ skipping 2672 matching lines @@
 class A {
   void m() {
     try {} catch (e) {rethrow;}
   }
 }''');
     resolve(source);
     assertNoErrors(source);
     verify([source]);
   }
 
+  void test_return_in_generator_async() {
+    Source source = addSource('''
+import 'dart:async';
+Stream<int> f() async* {
+  return;
+}
+''');
+    resolve(source);
+    assertNoErrors(source);
+    verify([source]);
+  }
+
+  void test_return_in_generator_sync() {
+    Source source = addSource('''
+Iterable<int> f() sync* {
+  return;
+}
+''');
+    resolve(source);
+    assertNoErrors(source);
+    verify([source]);
+  }
+
   void test_returnInGenerativeConstructor() {
     Source source = addSource(r'''
 class A {
   A() { return; }
 }''');
     resolve(source);
     assertNoErrors(source);
     verify([source]);
   }
 
@@ skipping 973 matching lines @@
     resolve(source);
     assertNoErrors(source);
     verify([source]);
     reset();
   }
 
   void _check_wrongNumberOfParametersForOperator1(String name) {
     _check_wrongNumberOfParametersForOperator(name, "a");
   }
 }