Reland "[es6] Better support for built-ins subclassing."

test/mjsunit/es6/classes-subclass-builtins.js

+// Copyright 2015 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --allow-natives-syntax
+
+"use strict";
+
+
+function checkPrototypeChain(object, constructors) {
+  var proto = object.__proto__;
+  for (var i = 0; i < constructors.length; i++) {
+    assertEquals(constructors[i].prototype, proto);
+    assertEquals(constructors[i], proto.constructor);
+    proto = proto.__proto__;
+  }
+}
+
+
+(function() {
+  class A extends Boolean {
+    constructor(...args) {
+      assertTrue(%IsConstructCall());
+      super(...args);
+      this.a = 42;
+    }
+  }
+
+  var o = new A(true);
+  assertTrue(o instanceof Object);
+  assertTrue(o instanceof Boolean);
+  assertTrue(o instanceof A);
+  assertEquals("object", typeof o);
+  checkPrototypeChain(o, [A, Boolean]);
+  assertTrue(o.valueOf());
+  assertEquals(42, o.a);
+
+  var o1 = new A(false);
+  assertTrue(%HaveSameMap(o, o1));
+})();
+
+
+function TestErrorSubclassing(error) {
+  class A extends error {
+    constructor(...args) {
+      assertTrue(%IsConstructCall());
+      super(...args);
+      this.a = 42;
+    }
+  }
+
+  var o = new A("message");
+  assertTrue(o instanceof Object);
+  assertTrue(o instanceof error);
+  assertTrue(o instanceof Error);
+  assertTrue(o instanceof A);
+  assertEquals("object", typeof o);
+  if (error == Error) {
+    checkPrototypeChain(o, [A, Error, Object]);
+  } else {
+    checkPrototypeChain(o, [A, error, Error, Object]);
+  }
+  assertEquals("message", o.message);
+  assertEquals(error.name + ": message", o.toString());
+  assertEquals(42, o.a);
+
+  var o1 = new A("achtung!");
+  assertTrue(%HaveSameMap(o, o1));
+}
+
+
+(function() {
+  TestErrorSubclassing(Error);
+  TestErrorSubclassing(EvalError);
+  TestErrorSubclassing(RangeError);
+  TestErrorSubclassing(ReferenceError);
+  TestErrorSubclassing(SyntaxError);
+  TestErrorSubclassing(TypeError);
+  TestErrorSubclassing(URIError);
+})();
+
+
+(function() {
+  class A extends Number {
+    constructor(...args) {
+      assertTrue(%IsConstructCall());
+      super(...args);
+      this.a = 42;
+    }
+  }
+
+  var o = new A(153);
+  assertTrue(o instanceof Object);
+  assertTrue(o instanceof Number);
+  assertTrue(o instanceof A);
+  assertEquals("object", typeof o);
+  checkPrototypeChain(o, [A, Number, Object]);
+  assertEquals(153, o.valueOf());
+  assertEquals(42, o.a);
+
+  var o1 = new A(312);
+  assertTrue(%HaveSameMap(o, o1));
+})();
+
+
+(function() {
+  class A extends Date {
+    constructor(...args) {
+      assertTrue(%IsConstructCall());
+      super(...args);
+      this.a = 42;
+    }
+  }
+
+  var o = new A(1234567890);
+  assertTrue(o instanceof Object);
+  assertTrue(o instanceof Date);
+  assertTrue(o instanceof A);
+  assertEquals("object", typeof o);
+  checkPrototypeChain(o, [A, Date, Object]);
+  assertEquals(1234567890, o.getTime());
+  assertEquals(42, o.a);
+
+  var o1 = new A(2015, 10, 29);
+  assertEquals(2015, o1.getFullYear());
+  assertEquals(10, o1.getMonth());
+  assertEquals(29, o1.getDate());
+  assertTrue(%HaveSameMap(o, o1));
+})();
+
+
+(function() {
+  class A extends String {
+    constructor(...args) {
+      assertTrue(%IsConstructCall());
+      super(...args);
+      this.a = 42;
+    }
+  }
+
+  var o = new A("foo");
+  assertTrue(o instanceof Object);
+  assertTrue(o instanceof String);
+  assertTrue(o instanceof A);
+  assertEquals("object", typeof o);
+  checkPrototypeChain(o, [A, String, Object]);
+
+  assertEquals("foo", o.valueOf());
+  assertEquals(42, o.a);
+
+  var o1 = new A("bar");
+  assertTrue(%HaveSameMap(o, o1));
+})();
+
+
+(function() {
+  class A extends RegExp {
+    constructor(...args) {
+      assertTrue(%IsConstructCall());
+      super(...args);
+      this.a = 42;
+    }
+  }
+
+  var o = new A("o..h");
+  assertTrue(o instanceof Object);
+  assertTrue(o instanceof RegExp);
+  assertTrue(o instanceof A);
+  assertEquals("object", typeof o);
+  checkPrototypeChain(o, [A, RegExp, Object]);
+  assertTrue(o.test("ouch"));
+  assertEquals(42, o.a);
+
+  var o1 = new A(7);
+  assertTrue(%HaveSameMap(o, o1));
+})();
+
+
+function TestArraySubclassing(array) {
+  class A extends array {
+    constructor(...args) {
+      assertTrue(%IsConstructCall());
+      super(...args);
+      this.a = 42;
+    }
+  }
+
+  var o = new array(13);
+  assertTrue(o instanceof Object);
+  assertTrue(o instanceof array);
+  assertEquals("object", typeof o);
+  checkPrototypeChain(o, [array, Object]);
+  assertEquals(13, o.length);
+
+  var o = new A(10);
+  assertTrue(o instanceof Object);
+  assertTrue(o instanceof array);
+  assertTrue(o instanceof A);
+  assertEquals("object", typeof o);
+  checkPrototypeChain(o, [A, array, Object]);
+  assertEquals(10, o.length);
+  assertEquals(42, o.a);
+
+  var o1 = new A(7);
+  assertTrue(%HaveSameMap(o, o1));
+}
+
+
+(function() {
+  TestArraySubclassing(Array);
+  TestArraySubclassing(Int8Array);
+  TestArraySubclassing(Uint8Array);
+  TestArraySubclassing(Uint8ClampedArray);
+  TestArraySubclassing(Int16Array);
+  TestArraySubclassing(Uint16Array);
+  TestArraySubclassing(Int32Array);
+  TestArraySubclassing(Uint32Array);
+  TestArraySubclassing(Float32Array);
+  TestArraySubclassing(Float64Array);
+})();
+
+
+(function() {
+  class A extends ArrayBuffer {
+    constructor(...args) {
+      assertTrue(%IsConstructCall());
+      super(...args);
+      this.a = 42;
+    }
+  }
+
+  var o = new A(16);
+  assertTrue(o instanceof Object);
+  assertTrue(o instanceof ArrayBuffer);
+  assertTrue(o instanceof A);
+  assertEquals("object", typeof o);
+  checkPrototypeChain(o, [A, ArrayBuffer, Object]);
+
+  assertEquals(16, o.byteLength);
+  assertEquals(42, o.a);
+
+  var o1 = new A("bar");
+  assertTrue(%HaveSameMap(o, o1));
+
+
+  class MyInt32Array extends Int32Array {
+    constructor(v, name) {
+      super(v);
+      this.name = name;
+    }
+  }
+
+  class MyUint32Array extends Uint32Array {
+    constructor(v, name) {
+      super(v);
+      this.name = name;
+    }
+  }
+
+  var int32view = new MyInt32Array(o, "cats");
+  var uint32view = new MyUint32Array(o, "dogs");
+
+  int32view[0] = -2;
+  uint32view[1] = 0xffffffff;
+
+  assertEquals("cats", int32view.name);
+  assertEquals("dogs", uint32view.name);
+  assertEquals(-2, int32view[0]);
+  assertEquals(-1, int32view[1]);
+  assertEquals(0xfffffffe, uint32view[0]);
+  assertEquals(0xffffffff, uint32view[1]);
+})();
+
+
+(function() {
+  class A extends DataView {
+    constructor(...args) {
+      assertTrue(%IsConstructCall());
+      super(...args);
+      this.a = 42;
+    }
+  }
+
+  var buffer = new ArrayBuffer(16);
+  var o = new A(buffer);
+  assertTrue(o instanceof Object);
+  assertTrue(o instanceof DataView);
+  assertTrue(o instanceof A);
+  assertEquals("object", typeof o);
+  checkPrototypeChain(o, [A, DataView, Object]);
+
+  o.setUint32(0, 0xcafebabe, false);
+  assertEquals(0xcafebabe, o.getUint32(0, false));
+  assertEquals(0xbebafeca, o.getUint32(0, true));
+  assertEquals(42, o.a);
+
+  var o1 = new A(buffer);
+  assertTrue(%HaveSameMap(o, o1));
+
+})();
+
+
+(function() {
+  class A extends Boolean {
+    constructor() {
+      assertTrue(%IsConstructCall());
+      super(true);
+      this.a00 = 0
+      this.a01 = 0
+      this.a02 = 0
+      this.a03 = 0
+      this.a04 = 0
+      this.a05 = 0
+      this.a06 = 0
+      this.a07 = 0
+      this.a08 = 0
+      this.a09 = 0
+      this.a10 = 0
+      this.a11 = 0
+      this.a12 = 0
+      this.a13 = 0
+      this.a14 = 0
+      this.a15 = 0
+      this.a16 = 0
+      this.a17 = 0
+      this.a18 = 0
+      this.a19 = 0
+    }
+  }
+
+  class B extends A {
+    constructor() {
+      assertTrue(%IsConstructCall());
+      super();
+      this.b00 = 0
+      this.b01 = 0
+      this.b02 = 0
+      this.b03 = 0
+      this.b04 = 0
+      this.b05 = 0
+      this.b06 = 0
+      this.b07 = 0
+      this.b08 = 0
+      this.b09 = 0
+      this.b10 = 0
+      this.b11 = 0
+      this.b12 = 0
+      this.b13 = 0
+      this.b14 = 0
+      this.b15 = 0
+      this.b16 = 0
+      this.b17 = 0
+      this.b18 = 0
+      this.b19 = 0
+    }
+  }
+
+  class C extends B {
+    constructor() {
+      assertTrue(%IsConstructCall());
+      super();
+      this.c00 = 0
+      this.c01 = 0
+      this.c02 = 0
+      this.c03 = 0
+      this.c04 = 0
+      this.c05 = 0
+      this.c06 = 0
+      this.c07 = 0
+      this.c08 = 0
+      this.c09 = 0
+      this.c10 = 0
+      this.c11 = 0
+      this.c12 = 0
+      this.c13 = 0
+      this.c14 = 0
+      this.c15 = 0
+      this.c16 = 0
+      this.c17 = 0
+      this.c18 = 0
+      this.c19 = 0
+    }
+  }
+
+  var o = new C();
+  assertTrue(o instanceof Object);
+  assertTrue(o instanceof Boolean);
+  assertTrue(o instanceof A);
+  assertTrue(o instanceof B);
+  assertTrue(o instanceof C);
+  assertEquals("object", typeof o);
+  checkPrototypeChain(o, [C, B, A, Boolean, Object]);
+})();
+
+
+(function() {
+  assertThrows("class A extends undefined {}");
+  assertThrows("class B extends NaN {}");
+  assertThrows("class C extends Infinity {}");
+})();
+
+
+(function() {
+  class A extends null {}
+  assertThrows("new A");
+})();
+
+
+(function() {
+  class A extends Symbol {}
+  assertThrows("new A");
+})();