tests/compiler/dart2js_native/fixup_get_tag_test.dart

// Copyright (c) 2013, 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";

// Test for dartExperimentalFixupGetTag.

@Native("A")
class Foo {
  // There is one native class with dispatch tag 'A'.
  token() native ;
}

void setup() native r"""

dartExperimentalFixupGetTag = function (originalGetTag) {
  function fixedGetTag(obj) {
    // Local JS 'class' B is made to be another implementation of the native
    // class with tag 'A'.
    if (obj instanceof B) return 'A';
    // Other classes behave as before.
    return originalGetTag(obj);
  }
  return fixedGetTag;
};

function A(){ }
A.prototype.token = function () { return 'isA'; }

function B(){ }
B.prototype.token = function () { return 'isB'; }

makeA = function() { return new A; };
makeB = function() { return new B; };

self.nativeConstructor(A);
""";

makeA() native ;
makeB() native ;

main() {
  nativeTesting();
  setup();

  var a = makeA();
  var b = makeB();

  Expect.equals('isA', a.token());

  // This call succeeds because the fixed-up 'getTag' method returns Foo's
  // dispatch tag, and B is a faithful polyfil for Foo/A.
  Expect.equals('isB', b.token());

  Expect.isTrue(a is Foo);
  Expect.isTrue(b is Foo);
}