|  | // 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. | 
|  |  | 
|  | import "native_testing.dart"; | 
|  |  | 
|  | @Native("A") | 
|  | class A { | 
|  | var foo; | 
|  | } | 
|  |  | 
|  | class B { | 
|  | var foo; | 
|  | } | 
|  |  | 
|  | nativeId(x) native; | 
|  |  | 
|  | void setup() { | 
|  | JS('', r""" | 
|  | (function(){ | 
|  | nativeId = function(x) { return x; } | 
|  | })()"""); | 
|  | } | 
|  |  | 
|  | main() { | 
|  | setup(); | 
|  | var b = new B(); | 
|  | b.foo = (x) => x + 1; | 
|  | b = nativeId(b); // Inferrer doesn't know if A has been instantiated. | 
|  | // At this point b could be A or B. The call to "foo" thus needs to go through | 
|  | // an interceptor. Tests that the interceptor works for retrieving the field | 
|  | // and invoking the closure. | 
|  | // Use a type-check to guarantee that b is a "B". | 
|  | if (b is B) { | 
|  | Expect.equals(499, b.foo(498)); | 
|  | } | 
|  | } |