[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__;
+  }
+}
+
+
+/*
+// TODO(ishell): BUG: v8:3101, fix this case.
+(function() {
+  class A extends Object {
+    constructor(v) {
+      assertTrue(%IsConstructCall());
+      super(v);
+      this.a = 42;
+    }
+  }
+
+  var s = new A("foo");
+  assertTrue(s instanceof Object);
+  assertTrue(s instanceof String);
+  assertTrue(s instanceof A);
+  assertEquals("foo", s.valueOf());
+  assertEquals(42, s.a);
+
+  var s1 = new A("bar");
+  assertTrue(%HaveSameMap(s, s1));
+
+
+  var n = new A(153);
+  assertTrue(n instanceof Object);
+  assertTrue(n instanceof Number);
+  assertTrue(n instanceof A);
+  assertEquals(153, n.valueOf());
+  assertEquals(42, n.a);
+
+  var n1 = new A(312);
+  assertTrue(%HaveSameMap(n, n1));
+  assertTrue(%HaveSameMap(n, s));
+
+
+  var b = new A(true);
+  assertTrue(b instanceof Object);
+  assertTrue(b instanceof Boolean);
+  assertTrue(b instanceof A);
+  assertEquals(153, b.valueOf());
+  assertEquals(42, b.a);
+
+  var b1 = new A(true);
+  assertTrue(%HaveSameMap(b, b1));
+  assertTrue(%HaveSameMap(b, s));
+
+})();
+//*/
+
+
+(function() {
+  class A extends String {
+    constructor(v) {
+      assertTrue(%IsConstructCall());
+      super(v);
+      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]);
+
+  assertEquals("foo", o.valueOf());
+  assertEquals(42, o.a);
+
+  var o1 = new A("bar");
+  assertTrue(%HaveSameMap(o, o1));
+})();
+
+
+(function() {
+  class A extends Number {
+    constructor(v) {
+      assertTrue(%IsConstructCall());
+      super(v);
+      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]);
+  assertEquals(153, o.valueOf());
+  assertEquals(42, o.a);
+
+  var o1 = new A(312);
+  assertTrue(%HaveSameMap(o, o1));
+})();
+
+
+(function() {
+  class A extends Boolean {
+    constructor(v) {
+      assertTrue(%IsConstructCall());
+      super(v);
+      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));
+})();
+
+
+/*
+// TODO(ishell): BUG: v8:3101, fix this case.
+(function() {
+  class A extends Function {
+    constructor(v) {
+      assertTrue(%IsConstructCall());
+      super(v);
+      this.a = 42;
+    }
+  }
+
+  var o = new A("return 153;");
+  assertTrue(o instanceof Function);
+  assertTrue(o instanceof A);
+  assertTrue(o instanceof Object);
+  assertEquals("function", typeof o);
+  checkPrototypeChain(o, [A, Function]);
+  assertEquals(42, o.a);
+
+  var o1 = new A("return 312;");
+  assertTrue(%HaveSameMap(o, o1));
+})();
+//*/
+
+
+(function() {
+  class A extends Array {
+    constructor(v) {
+      assertTrue(%IsConstructCall());
+      super(v);
+      this.a = 42;
+    }
+  }
+
+  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]);
+  assertEquals(10, o.length);
+  assertEquals(42, o.a);
+
+  var o1 = new A(7);
+  assertTrue(%HaveSameMap(o, o1));
+})();
+
+
+(function() {
+  class A extends Int32Array {
+    constructor(v) {
+      assertTrue(%IsConstructCall());
+      super(v);
+      this.a = 42;
+    }
+  }
+
+  var o = new A(10);
+  assertTrue(o instanceof Object);
+  assertTrue(o instanceof Int32Array);
+  assertTrue(o instanceof A);
+  assertEquals("object", typeof o);
+  checkPrototypeChain(o, [A, Int32Array]);
+  assertEquals(10, o.length);
+  assertEquals(42, o.a);
+
+  var o1 = new A(7);
+  assertTrue(%HaveSameMap(o, o1));
+})();
+
+
+(function() {
+  class A extends RegExp {
+    constructor(v) {
+      assertTrue(%IsConstructCall());
+      super(v);
+      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]);
+  assertTrue(o.test("ouch"));
+  assertEquals(42, o.a);
+
+  var o1 = new A(7);
+  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]);
+})();
+
+
+(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");
+})();