add test related to #264 and #228

test/checker/checker_test.dart

 // Copyright (c) 2015, 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.
 
 /// General type checking tests
 library dev_compiler.test.checker_test;
 
 import 'package:test/test.dart';
 
 import '../testing.dart';
@@ skipping 2657 matching lines @@
       }'''
   },
       customUrlMappings: {
     'dart:foobar': '$testDirectory/checker/dart_foobar.dart'
   }));
 
   group('function modifiers', () {
     test('async', () => testChecker({
       '/main.dart': '''
         import 'dart:async';
+        import 'dart:math' show Random;
 
         dynamic x;
 
         foo1() async => x;
         Future foo2() async => x;
         Future<int> foo3() async => (/*info:DynamicCast*/x);
-        Future<int> foo4() async => (/*severe:StaticTypeError*/new Future<int>(x));
+        Future<int> foo4() async => (/*severe:StaticTypeError*/new Future<int>.value(/*info:DynamicCast*/x));
 
         bar1() async { return x; }
         Future bar2() async { return x; }
         Future<int> bar3() async { return (/*info:DynamicCast*/x); }
-        Future<int> bar4() async { return (/*severe:StaticTypeError*/new Future<int>(x)); }
+        Future<int> bar4() async { return (/*severe:StaticTypeError*/new Future<int>.value(/*info:DynamicCast*/x)); }
 
         int y;
         Future<int> z;
 
         void baz() async {
           int a = /*info:DynamicCast*/await x;
           int b = await y;
           int c = await z;
           String d = /*severe:StaticTypeError*/await z;
         }
 
         Future<bool> get issue_264 async {
           await 42;
-          return false;
+          if (new Random().nextBool()) {
+            return true;
+          } else {
+            return /*severe:StaticTypeError*/new Future<bool>.value(false);
+          }
         }
     '''
     }));
 
     test('async*', () => testChecker({
       '/main.dart': '''
         import 'dart:async';
 
         dynamic x;
 
@@ skipping 23 matching lines @@
 
         baz1() sync* { yield* (/*info:DynamicCast*/x); }
         Iterable baz2() sync* { yield* (/*info:DynamicCast*/x); }
         Iterable<int> baz3() sync* { yield* (/*warning:DownCastComposite*/x); }
         Iterable<int> baz4() sync* { yield* new Iterable<int>(); }
         Iterable<int> baz5() sync* { yield* (/*info:InferredTypeAllocation*/new Iterable()); }
     '''
     }));
   });
 }