[es6] Make new.target work in functions

test/mjsunit/harmony/new-target.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: --harmony-classes --harmony-new-target --harmony-reflect
+// Flags: --harmony-rest-parameters --harmony-arrow-functions
+
+
+(function TestClass() {
+  'use strict';
+
+  var calls = 0;
+  class Base {
+    constructor(_) {
+      assertEquals(Base, new.target);
+      calls++;
+    }
+  }
+  assertInstanceof(new Base(1), Base);
+  assertInstanceof(new Base(1, 2), Base);
+  assertInstanceof(new Base(), Base);
+  assertEquals(3, calls);
+})();
+
+
+(function TestDerivedClass() {
+  'use strict';
+
+  var calls = 0;
+  class Base {
+    constructor(expected) {
+      assertEquals(expected, new.target);
+    }
+  }
+  class Derived extends Base {
+    constructor(expected) {
+      super(expected);
+      assertEquals(expected, new.target);
+      calls++;
+    }
+  }
+  new Derived(Derived, 'extra');
+  new Derived(Derived);
+  assertEquals(2, calls);
+
+  class Derived2 extends Derived {}
+  calls = 0;
+  new Derived2(Derived2);
+  new Derived2(Derived2, 'extra');
+  assertEquals(2, calls);
+})();
+
+
+(function TestFunctionCall() {
+  var calls;
+  function f(expected) {
+    calls++;
+    assertEquals(expected, new.target);
+  }
+
+  calls = 0;
+  f(undefined);
+  f(undefined, 'extra');
+  f();
+  assertEquals(3, calls);
+
+  calls = 0;
+  f.call({}, undefined);
+  f.call({}, undefined, 'extra');
+  f.call({});
+  assertEquals(3, calls);
+
+  calls = 0;
+  f.apply({}, [undefined]);
+  f.apply({}, [undefined, 'extra']);
+  f.apply({}, []);
+  assertEquals(3, calls);
+})();
+
+
+(function TestFunctionConstruct() {
+  var calls;
+  function f(expected) {
+    calls++;
+    assertEquals(expected, new.target);
+  }
+
+  calls = 0;
+  new f(f);
+  new f(f, 'extra');
+  assertEquals(2, calls);
+})();
+
+
+(function TestClassExtendsFunction() {
+  'use strict';
+
+  var calls = 0;
+  function f(expected) {
+    assertEquals(expected, new.target);
+  }
+  class Derived extends f {
+    constructor(expected) {
+      super(expected);
+      assertEquals(expected, new.target);
+      calls++;
+    }
+  }
+
+  new Derived(Derived);
+  new Derived(Derived, 'extra');
+  assertEquals(2, calls);
+})();
+
+
+(function TestFunctionReturnObject() {
+  function f(expected) {
+    assertEquals(expected, new.target);
+    return /abc/;
+  }
+
+  assertInstanceof(new f(f), RegExp);
+  assertInstanceof(new f(f, 'extra'), RegExp);
+
+  assertInstanceof(f(undefined), RegExp);
+  assertInstanceof(f(), RegExp);
+  assertInstanceof(f(undefined, 'extra'), RegExp);
+})();
+
+
+(function TestClassReturnObject() {
+  'use strict';
+
+  class Base {
+    constructor(expected) {
+      assertEquals(expected, new.target);
+      return /abc/;
+    }
+  }
+
+  assertInstanceof(new Base(Base), RegExp);
+  assertInstanceof(new Base(Base, 'extra'), RegExp);
+
+  class Derived extends Base {}
+  assertInstanceof(new Derived(Derived), RegExp);
+  assertInstanceof(new Derived(Derived, 'extra'), RegExp);
+
+  class Derived2 extends Base {
+    constructor(expected) {
+      super(expected);
+      assertInstanceof(this, RegExp);
+    }
+  }
+  assertInstanceof(new Derived2(Derived2), RegExp);
+  assertInstanceof(new Derived2(Derived2, 'extra'), RegExp);
+})();
+
+
+/*
+// TODO(arv): Reflect.construct does not work correctly with a third argument.
+(function TestReflectConstruct() {
+  var calls = 0;
+  function f(expected) {
+    calls++;
+    assertEquals(expected, new.target);
+  }
+
+  var o = Reflect.construct(f, [f]);
+  assertEquals(Object.getPrototypeOf(o), f.prototype);
+  o = Reflect.construct(f, [f, 'extra']);
+  assertEquals(Object.getPrototypeOf(o), f.prototype);
+  assertEquals(2, calls);
+
+  calls = 0;
+  o = Reflect.construct(f, [f], f);
+  assertEquals(Object.getPrototypeOf(o), f.prototype);
+  o = Reflect.construct(f, [f, 'extra'], f);
+  assertEquals(Object.getPrototypeOf(o), f.prototype);
+  assertEquals(2, calls);
+
+
+  function g() {}
+  calls = 0;
+  o = Reflect.construct(f, [g], g);
+  assertEquals(Object.getPrototypeOf(o), g.prototype);
+  o = Reflect.construct(f, [g, 'extra'], g);
+  assertEquals(Object.getPrototypeOf(o), g.prototype);
+  assertEquals(2, calls);
+})();
+*/
+
+
+(function TestRestParametersFunction() {
+  function f(...rest) {
+    assertEquals(rest[0], new.target);
+  }
+
+  assertInstanceof(new f(f), f);
+  assertInstanceof(new f(f, 'extra'), f);
+})();
+
+
+(function TestRestParametersClass() {
+  'use strict';
+
+  class Base {
+    constructor(...rest) {
+      assertEquals(rest[0], new.target);
+    }
+  }
+
+  assertInstanceof(new Base(Base), Base);
+  assertInstanceof(new Base(Base, 'extra'), Base);
+
+  class Derived extends Base {}
+
+  assertInstanceof(new Derived(Derived), Derived);
+  assertInstanceof(new Derived(Derived, 'extra'), Derived);
+})();
+
+
+(function TestArrowFunction() {
+  function f(expected) {
+    (() => {
+      assertEquals(expected, new.target);
+    })();
+  }
+
+  assertInstanceof(new f(f), f);
+  assertInstanceof(new f(f, 'extra'), f);
+})();
+
+
+(function TestRestParametersClass() {
+  'use strict';
+
+  class Base {
+    constructor(expected) {
+      (() => {
+        assertEquals(expected, new.target);
+      })();
+    }
+  }
+
+  assertInstanceof(new Base(Base), Base);
+  assertInstanceof(new Base(Base, 'extra'), Base);
+
+  class Derived extends Base {}
+
+  assertInstanceof(new Derived(Derived), Derived);
+  assertInstanceof(new Derived(Derived, 'extra'), Derived);
+})();
+
+
+(function TestSloppyArguments() {
+  var length, a0, a1, a2, nt;
+  function f(x) {
+    assertEquals(length, arguments.length);
+    assertEquals(a0, arguments[0]);
+    assertEquals(a1, arguments[1]);
+    assertEquals(a2, arguments[2]);
+    assertEquals(nt, new.target);
+
+    if (length > 0) {
+      x = 42;
+      assertEquals(42, x);
+      assertEquals(42, arguments[0]);
+
+      arguments[0] = 33;
+      assertEquals(33, x);
+      assertEquals(33, arguments[0]);
+    }
+  }
+
+  nt = f;
+  length = 0;
+  new f();
+
+  length = 1;
+  a0 = 1;
+  new f(1);
+
+  length = 2;
+  a0 = 1;
+  a1 = 2;
+  new f(1, 2);
+
+  length = 3;
+  a0 = 1;
+  a1 = 2;
+  a2 = 3;
+  new f(1, 2, 3);
+
+  nt = undefined;
+  a0 = a1 = a2 = undefined;
+  length = 0;
+  f();
+
+  length = 1;
+  a0 = 1;
+  f(1);
+
+  length = 2;
+  a0 = 1;
+  a1 = 2;
+  f(1, 2);
+
+  length = 3;
+  a0 = 1;
+  a1 = 2;
+  a2 = 3;
+  f(1, 2, 3);
+})();
+
+
+(function TestStrictArguments() {
+  var length, a0, a1, a2, nt;
+  function f(x) {
+    'use strict';
+    assertEquals(length, arguments.length);
+    assertEquals(a0, arguments[0]);
+    assertEquals(a1, arguments[1]);
+    assertEquals(a2, arguments[2]);
+    assertEquals(nt, new.target);
+
+    if (length > 0) {
+      x = 42;
+      assertEquals(a0, arguments[0]);
+
+      arguments[0] = 33;
+      assertEquals(33, arguments[0]);
+    }
+  }
+
+  nt = f;
+  length = 0;
+  new f();
+
+  length = 1;
+  a0 = 1;
+  new f(1);
+
+  length = 2;
+  a0 = 1;
+  a1 = 2;
+  new f(1, 2);
+
+  length = 3;
+  a0 = 1;
+  a1 = 2;
+  a2 = 3;
+  new f(1, 2, 3);
+
+  nt = undefined;
+  a0 = a1 = a2 = undefined;
+  length = 0;
+  f();
+
+  length = 1;
+  a0 = 1;
+  f(1);
+
+  length = 2;
+  a0 = 1;
+  a1 = 2;
+  f(1, 2);
+
+  length = 3;
+  a0 = 1;
+  a1 = 2;
+  a2 = 3;
+  f(1, 2, 3);
+})();