Add JSNative utility class with static methods methods to efficiently manipulate typed JSInterop ob…

tests/html/js_util_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.
+
+@JS()
+library js_native_test;
+
+import 'dart:async';
+import 'dart:html';
+import 'dart:typed_data' show ByteBuffer, Int32List;
+import 'dart:indexed_db' show IdbFactory, KeyRange;
+
+import 'package:js/js.dart';
+import 'package:js/js_util.dart' as js_util;
+
+import 'package:unittest/unittest.dart';
+import 'package:unittest/html_individual_config.dart';
+
+_injectJs() {
+  final script = new ScriptElement();
+  script.type = 'text/javascript';
+  script.innerHtml = r"""
+var x = 42;
+
+var _x = 123;
+
+var myArray = ["value1"];
+
+function returnThis() {
+  return this;
+}
+
+function getTypeOf(o) {
+  return typeof(o);
+}
+
+function Foo(a) {
+  this.a = a;
+}
+
+Foo.b = 38;
+
+Foo.prototype.bar = function() {
+  return this.a;
+}
+Foo.prototype.toString = function() {
+  return "I'm a Foo a=" + this.a;
+}
+
+var container = new Object();
+container.Foo = Foo;
+
+function checkMap(m, key, value) {
+  if (m.hasOwnProperty(key))
+    return m[key] == value;
+  else
+    return false;
+}
+
+""";
+  document.body.append(script);
+}
+
+@JS()
+external bool checkMap(m, String, value);
+
+@JS('JSON.stringify')
+external String stringify(o);
+
+@JS('Node')
+external get JSNodeType;
+
+@JS('Element')
+external get JSElementType;
+
+@JS('Text')
+external get JSTextType;
+
+@JS('HTMLCanvasElement')
+external get JSHtmlCanvasElementType;
+
+@JS()
+class Foo {
+  external Foo(num a);
+
+  external num get a;
+  external num bar();
+}
+
+@JS('Foo')
+external get JSFooType;
+
+@JS()
+@anonymous
+class ExampleTypedLiteral {
+  external factory ExampleTypedLiteral({a, b, JS$_c, JS$class});
+
+  external get a;
+  external get b;
+  external get JS$_c;
+  external set JS$_c(v);
+  // Identical to JS$_c but only accessible within the library.
+  external get _c;
+  external get JS$class;
+  external set JS$class(v);
+}
+
+@JS("Object.prototype.hasOwnProperty")
+external get _hasOwnProperty;
+
+bool hasOwnProperty(o, String name) {
+  return js_util.callMethod(_hasOwnProperty, 'call', [o, name]);
+}
+
+main() {
+  _injectJs();
+  useHtmlIndividualConfiguration();
+
+  group('js_util.jsify()', () {
+    test('convert a List', () {
+      final list = [1, 2, 3, 4, 5, 6, 7, 8];
+      var array = js_util.jsify(list);
+      expect(array is List, isTrue);
+      expect(identical(array, list), isFalse);
+      expect(array.length, equals(list.length));
+      for (var i = 0; i < list.length; i++) {
+        expect(array[i], equals(list[i]));
+      }
+    });
+
+    test('convert an Iterable', () {
+      final set = new Set.from([1, 2, 3, 4, 5, 6, 7, 8]);
+      var array = js_util.jsify(set);
+      expect(array is List, isTrue);
+      expect(array.length, equals(set.length));
+      for (var i = 0; i < array.length; i++) {
+        expect(set.contains(array[i]), isTrue);
+      }
+    });
+
+    test('convert a Map', () {
+      var map = {'a': 1, 'b': 2, 'c': 3};
+      var jsMap = js_util.jsify(map);
+      expect(jsMap is! List, isTrue);
+      for (var key in map.keys) {
+        expect(checkMap(jsMap, key, map[key]), isTrue);
+      }
+    });
+
+    test('deep convert a complex object', () {
+      final object = {
+        'a': [
+          1,
+          [2, 3]
+        ],
+        'b': {'c': 3, 'd': new Foo(42)},
+        'e': null
+      };
+      var jsObject = js_util.jsify(object);
+      expect(js_util.getProperty(jsObject, 'a')[0], equals(object['a'][0]));
+      expect(
+          js_util.getProperty(jsObject, 'a')[1][0], equals(object['a'][1][0]));
+      expect(
+          js_util.getProperty(jsObject, 'a')[1][1], equals(object['a'][1][1]));
+      expect(js_util.getProperty(js_util.getProperty(jsObject, 'b'), 'c'),
+          equals(object['b']['c']));
+      expect(js_util.getProperty(js_util.getProperty(jsObject, 'b'), 'd'),
+          equals(object['b']['d']));
+      expect(
+          js_util.callMethod(
+              js_util.getProperty(js_util.getProperty(jsObject, 'b'), 'd'),
+              'bar', []),
+          equals(42));
+      expect(js_util.getProperty(jsObject, 'e'), isNull);
+    });
+
+    test('throws if object is not a Map or Iterable', () {
+      expect(() => js_util.jsify('a'),
+          throwsA(new isInstanceOf<ArgumentError>()));
+    });
+  });
+
+  group('js_util.newObject', () {
+    test('create', () {
+      expect(identical(js_util.newObject(), js_util.newObject()), isFalse);
+    });
+
+    test('callMethod', () {
+      var o = js_util.newObject();
+      expect(js_util.callMethod(o, 'toString', []), equals('[object Object]'));
+      expect(stringify(o), equals('{}'));
+    });
+
+    test('properties', () {
+      var o = js_util.newObject();
+      expect(js_util.hasProperty(o, 'foo bar'), isFalse);
+      expect(js_util.hasProperty(o, 'toString'), isTrue);
+      expect(hasOwnProperty(o, 'toString'), isFalse);
+      expect(hasOwnProperty(o, 'foo bar'), isFalse);
+      js_util.setProperty(o, 'foo bar', 42);
+      expect(hasOwnProperty(o, 'foo bar'), isTrue);
+      expect(js_util.getProperty(o, 'foo bar'), equals(42));
+      expect(js_util.hasProperty(o, 'foo bar'), isTrue);
+      expect(stringify(o), equals('{"foo bar":42}'));
+    });
+  });
+
+  group('hasProperty', () {
+    test('typed object', () {
+      var f = new Foo(42);
+      expect(js_util.hasProperty(f, 'a'), isTrue);
+      expect(js_util.hasProperty(f, 'toString'), isTrue);
+      js_util.setProperty(f, '__proto__', null);
+      expect(js_util.hasProperty(f, 'toString'), isFalse);
+    });
+    test('typed literal', () {
+      var l =
+          new ExampleTypedLiteral(a: 'x', b: 42, JS$_c: null, JS$class: true);
+      expect(js_util.hasProperty(l, 'a'), isTrue);
+      expect(js_util.hasProperty(l, 'b'), isTrue);
+      expect(js_util.hasProperty(l, '_c'), isTrue);
+      expect(l.JS$_c, isNull);
+      expect(js_util.hasProperty(l, 'class'), isTrue);
+      // JS$_c escapes to _c so the property JS$_c will not exist on the object.
+      expect(js_util.hasProperty(l, r'JS$_c'), isFalse);
+      expect(js_util.hasProperty(l, r'JS$class'), isFalse);
+      expect(l.JS$class, isTrue);
+
+      l = new ExampleTypedLiteral(a: null);
+      expect(js_util.hasProperty(l, 'a'), isTrue);
+      expect(js_util.hasProperty(l, 'b'), isFalse);
+      expect(js_util.hasProperty(l, '_c'), isFalse);
+      expect(js_util.hasProperty(l, 'class'), isFalse);
+
+      l = new ExampleTypedLiteral(JS$_c: 74);
+      expect(js_util.hasProperty(l, '_c'), isTrue);
+      expect(l.JS$_c, equals(74));
+    });
+  });
+
+  group('getProperty', () {
+    test('typed object', () {
+      var f = new Foo(42);
+      expect(js_util.getProperty(f, 'a'), equals(42));
+      expect(js_util.getProperty(f, 'toString') is Function, isTrue);
+      js_util.setProperty(f, '__proto__', null);
+      expect(js_util.getProperty(f, 'toString'), isNull);
+    });
+
+    test('typed literal', () {
+      var l = new ExampleTypedLiteral(a: 'x', b: 42, JS$_c: 7, JS$class: true);
+      expect(js_util.getProperty(l, 'a'), equals('x'));
+      expect(js_util.getProperty(l, 'b'), equals(42));
+      expect(js_util.getProperty(l, '_c'), equals(7));
+      expect(l.JS$_c, equals(7));
+      expect(js_util.getProperty(l, 'class'), isTrue);
+      expect(js_util.getProperty(l, r'JS$_c'), isNull);
+      expect(js_util.getProperty(l, r'JS$class'), isNull);
+    });
+  });
+
+  group('setProperty', () {
+    test('typed object', () {
+      var f = new Foo(42);
+      expect(js_util.getProperty(f, 'a'), equals(42));
+      js_util.setProperty(f, 'a', 100);
+      expect(f.a, equals(100));
+      expect(js_util.getProperty(f, 'a'), equals(100));
+    });
+
+    test('typed literal', () {
+      var l = new ExampleTypedLiteral();
+      js_util.setProperty(l, 'a', 'foo');
+      expect(js_util.getProperty(l, 'a'), equals('foo'));
+      expect(l.a, equals('foo'));
+      js_util.setProperty(l, 'a', l);
+      expect(identical(l.a, l), isTrue);
+      var list = ['arr'];
+      js_util.setProperty(l, 'a', list);
+      expect(identical(l.a, list), isTrue);
+      l.JS$class = 42;
+      expect(l.JS$class, equals(42));
+      js_util.setProperty(l, 'class', 100);
+      expect(l.JS$class, equals(100));
+    });
+  });
+
+  group('callMethod', () {
+    test('html object', () {
+      var canvas = new Element.tag('canvas');
+      expect(
+          identical(canvas.getContext('2d'),
+              js_util.callMethod(canvas, 'getContext', ['2d'])),
+          isTrue);
+    });
+
+    test('typed object', () {
+      var f = new Foo(42);
+      expect(js_util.callMethod(f, 'bar', []), equals(42));
+    });
+  });
+
+  group('instanceof', () {
+    test('html object', () {
+      var canvas = new Element.tag('canvas');
+      expect(js_util.instanceof(canvas, JSNodeType), isTrue);
+      expect(js_util.instanceof(canvas, JSTextType), isFalse);
+      expect(js_util.instanceof(canvas, JSElementType), isTrue);
+      expect(js_util.instanceof(canvas, JSHtmlCanvasElementType), isTrue);
+      var div = new Element.tag('div');
+      expect(js_util.instanceof(div, JSNodeType), isTrue);
+      expect(js_util.instanceof(div, JSTextType), isFalse);
+      expect(js_util.instanceof(div, JSElementType), isTrue);
+      expect(js_util.instanceof(div, JSHtmlCanvasElementType), isFalse);
+
+      var text = new Text('foo');
+      expect(js_util.instanceof(text, JSNodeType), isTrue);
+      expect(js_util.instanceof(text, JSTextType), isTrue);
+      expect(js_util.instanceof(text, JSElementType), isFalse);
+    });
+
+    test('typed object', () {
+      var f = new Foo(42);
+      expect(js_util.instanceof(f, JSFooType), isTrue);
+      expect(js_util.instanceof(f, JSNodeType), isFalse);
+    });
+
+    test('typed literal', () {
+      var l = new ExampleTypedLiteral();
+      expect(js_util.instanceof(l, JSFooType), isFalse);
+    });
+  });
+
+  group('callConstructor', () {
+    test('html object', () {
+      var textNode = js_util.callConstructor(JSTextType, ['foo']);
+      expect(js_util.instanceof(textNode, JSTextType), isTrue);
+      expect(textNode is Text, isTrue);
+      expect(textNode.text, equals('foo'));
+    });
+
+    test('typed object', () {
+      Foo f = js_util.callConstructor(JSFooType, [42]);
+      expect(f.a, equals(42));
+    });
+  });
+}