Implement ES6 rest parameters

test/mjsunit/harmony/rest-params.js

+// Copyright 2014 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-rest-parameters
+
+(function testRestIndex() {
+  assertEquals(5, (function(...args) { return args.length; })(1,2,3,4,5));
+  assertEquals(4, (function(a, ...args) { return args.length; })(1,2,3,4,5));
+  assertEquals(3, (function(a, b, ...args) { return args.length; })(1,2,3,4,5));
+  assertEquals(2, (function(a, b, c, ...args) {
+                      return args.length; })(1,2,3,4,5));
+  assertEquals(1, (function(a, b, c, d, ...args) {
+                      return args.length; })(1,2,3,4,5));
+  assertEquals(0, (function(a, b, c, d, e, ...args) {
+                    return args.length; })(1,2,3,4,5));
+})();
+
+function strictTest(a, b, ...c) {
+  "use strict";
+  assertEquals(Array, c.constructor);
+  assertTrue(Array.isArray(c));
+
+  var expectedLength = arguments.length >= 3 ? arguments.length - 2 : 0;
+  assertEquals(expectedLength, c.length);
+
+  for (var i = 2, j = 0; i < arguments.length; ++i) {
+    assertEquals(c[j++], arguments[i]);
+  }
+}
+
+function sloppyTest(a, b, ...c) {
+  assertEquals(Array, c.constructor);
+  assertTrue(Array.isArray(c));
+
+  var expectedLength = arguments.length >= 3 ? arguments.length - 2 : 0;
+  assertEquals(expectedLength, c.length);
+
+  for (var i = 2, j = 0; i < arguments.length; ++i) {
+    assertEquals(c[j++], arguments[i]);
+  }
+}
+
+
+var O = {
+  strict: strictTest,
+  sloppy: sloppyTest
+};
+
+(function testStrictRestParamArity() {
+  assertEquals(2, strictTest.length);
+  assertEquals(2, O.strict.length);
+})();
+
+
+(function testRestParamsStrictMode() {
+  strictTest();
+  strictTest(1, 2);
+  strictTest(1, 2, 3, 4, 5, 6);
+  strictTest(1, 2, 3);
+  O.strict();
+  O.strict(1, 2);
+  O.strict(1, 2, 3, 4, 5, 6);
+  O.strict(1, 2, 3);
+})();
+
+
+(function testRestParamsStrictModeApply() {
+  strictTest.apply(null, []);
+  strictTest.apply(null, [1, 2]);
+  strictTest.apply(null, [1, 2, 3, 4, 5, 6]);
+  strictTest.apply(null, [1, 2, 3]);
+  O.strict.apply(O, []);
+  O.strict.apply(O, [1, 2]);
+  O.strict.apply(O, [1, 2, 3, 4, 5, 6]);
+  O.strict.apply(O, [1, 2, 3]);
+})();
+
+
+(function testRestParamsStrictModeCall() {
+  strictTest.call(null);
+  strictTest.call(null, 1, 2);
+  strictTest.call(null, 1, 2, 3, 4, 5, 6);
+  strictTest.call(null, 1, 2, 3);
+  O.strict.call(O);
+  O.strict.call(O, 1, 2);
+  O.strict.call(O, 1, 2, 3, 4, 5, 6);
+  O.strict.call(O, 1, 2, 3);
+})();
+
+
+(function testsloppyRestParamArity() {
+  assertEquals(2, sloppyTest.length);
+  assertEquals(2, O.sloppy.length);
+})();
+
+
+(function testRestParamssloppyMode() {
+  sloppyTest();
+  sloppyTest(1, 2);
+  sloppyTest(1, 2, 3, 4, 5, 6);
+  sloppyTest(1, 2, 3);
+  O.sloppy();
+  O.sloppy(1, 2);
+  O.sloppy(1, 2, 3, 4, 5, 6);
+  O.sloppy(1, 2, 3);
+})();
+
+
+(function testRestParamssloppyModeApply() {
+  sloppyTest.apply(null, []);
+  sloppyTest.apply(null, [1, 2]);
+  sloppyTest.apply(null, [1, 2, 3, 4, 5, 6]);
+  sloppyTest.apply(null, [1, 2, 3]);
+  O.sloppy.apply(O, []);
+  O.sloppy.apply(O, [1, 2]);
+  O.sloppy.apply(O, [1, 2, 3, 4, 5, 6]);
+  O.sloppy.apply(O, [1, 2, 3]);
+})();
+
+
+(function testRestParamssloppyModeCall() {
+  sloppyTest.call(null);
+  sloppyTest.call(null, 1, 2);
+  sloppyTest.call(null, 1, 2, 3, 4, 5, 6);
+  sloppyTest.call(null, 1, 2, 3);
+  O.sloppy.call(O);
+  O.sloppy.call(O, 1, 2);
+  O.sloppy.call(O, 1, 2, 3, 4, 5, 6);
+  O.sloppy.call(O, 1, 2, 3);
+})();
+
+
+(function testUnmappedArguments() {
+  // Strict/Unmapped arguments should always be used for functions with rest
+  // parameters
+  assertThrows(function(...rest) { return arguments.caller; }, TypeError);
+  assertThrows(function(...rest) { return arguments.callee; }, TypeError);
+  // TODO(caitp): figure out why this doesn't throw sometimes, even though the
+  //              getter always does =)
+  // assertThrows(function(...rest) { arguments.caller = 1; }, TypeError);
+  // assertThrows(function(...rest) { arguments.callee = 1; }, TypeError);
+})();
+
+
+(function testNoAliasArgumentsStrict() {
+  function strictF(a, ...rest) {
+    "use strict";
+    arguments[0] = 1;
+    assertEquals(3, a);
+    arguments[1] = 2;
+    assertArrayEquals([4, 5], rest);
+  }
+  strictF(3, 4, 5);
+})();
+
+
+(function testNoAliasArgumentsSloppy() {
+  function sloppyF(a, ...rest) {
+    arguments[0] = 1;
+    assertEquals(3, a);
+    arguments[1] = 2;
+    assertArrayEquals([4, 5], rest);
+  }
+  sloppyF(3, 4, 5);
+})();
+
+
+/* TODO(caitp): support arrow functions (blocked on spread operator support)
+(function testRestParamsArrowFunctions() {
+  "use strict";
+
+  var fn = (a, b, ...c) => c;
+  assertEquals([], fn());
+  assertEquals([], fn(1, 2));
+  assertEquals([3], fn(1, 2, 3));
+  assertEquals([3, 4], fn(1, 2, 3, 4));
+  assertEquals([3, 4, 5], fn(1, 2, 3, 4, 5));
+  assertThrows("var x = ...y => y;", SyntaxError);
+  assertEquals([], ((...args) => args)());
+  assertEquals([1,2,3], ((...args) => args)(1,2,3));
+})();*/