Support rest parameters in arrow functions

test/mjsunit/harmony/arrow-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 --harmony-arrow-functions
+
+(function testRestIndex() {
+  assertEquals(5, ((...args) => args.length)(1,2,3,4,5));
+  assertEquals(4, ((a, ...args) => args.length)(1,2,3,4,5));
+  assertEquals(3, ((a, b, ...args) => args.length)(1,2,3,4,5));
+  assertEquals(2, ((a, b, c, ...args) => args.length)(1,2,3,4,5));
+  assertEquals(1, ((a, b, c, d, ...args) => args.length)(1,2,3,4,5));
+  assertEquals(0, ((a, b, c, d, e, ...args) => args.length)(1,2,3,4,5));
+})();
+
+// strictTest and sloppyTest should be called with descending natural
+// numbers, as in:
+//
+//   strictTest(6,5,4,3,2,1)
+//
+var strictTest = (a, b, ...c) => {
+  "use strict";
+  assertEquals(Array, c.constructor);
+  assertTrue(Array.isArray(c));
+
+  var expectedLength = (a === undefined) ? 0 : a - 2;
+  assertEquals(expectedLength, c.length);
+
+  for (var i = 2; i < a; ++i) {
+    assertEquals(c[i - 2], a - i);
+  }
+}
+
+var sloppyTest = (a, b, ...c) => {
+  assertEquals(Array, c.constructor);
+  assertTrue(Array.isArray(c));
+
+  var expectedLength = (a === undefined) ? 0 : a - 2;
+  assertEquals(expectedLength, c.length);
+
+  for (var i = 2; i < a; ++i) {
+    assertEquals(c[i - 2], a - i);
+  }
+}
+
+
+var O = {
+  strict: strictTest,
+  sloppy: sloppyTest
+};
+
+(function testStrictRestParamArity() {
+  assertEquals(2, strictTest.length);
+  assertEquals(2, O.strict.length);
+})();
+
+
+(function testRestParamsStrictMode() {
+  strictTest();
+  strictTest(2, 1);
+  strictTest(6, 5, 4, 3, 2, 1);
+  strictTest(3, 2, 1);
+  O.strict();
+  O.strict(2, 1);
+  O.strict(6, 5, 4, 3, 2, 1);
+  O.strict(3, 2, 1);
+})();
+
+
+(function testRestParamsStrictModeApply() {
+  strictTest.apply(null, []);
+  strictTest.apply(null, [2, 1]);
+  strictTest.apply(null, [6, 5, 4, 3, 2, 1]);
+  strictTest.apply(null, [3, 2, 1]);
+  O.strict.apply(O, []);
+  O.strict.apply(O, [2, 1]);
+  O.strict.apply(O, [6, 5, 4, 3, 2, 1]);
+  O.strict.apply(O, [3, 2, 1]);
+})();
+
+
+(function testRestParamsStrictModeCall() {
+  strictTest.call(null);
+  strictTest.call(null, 2, 1);
+  strictTest.call(null, 6, 5, 4, 3, 2, 1);
+  strictTest.call(null, 3, 2, 1);
+  O.strict.call(O);
+  O.strict.call(O, 2, 1);
+  O.strict.call(O, 6, 5, 4, 3, 2, 1);
+  O.strict.call(O, 3, 2, 1);
+})();
+
+
+(function testsloppyRestParamArity() {
+  assertEquals(2, sloppyTest.length);
+  assertEquals(2, O.sloppy.length);
+})();
+
+
+(function testRestParamssloppyMode() {
+  sloppyTest();
+  sloppyTest(2, 1);
+  sloppyTest(6, 5, 4, 3, 2, 1);
+  sloppyTest(3, 2, 1);
+  O.sloppy();
+  O.sloppy(2, 1);
+  O.sloppy(6, 5, 4, 3, 2, 1);
+  O.sloppy(3, 2, 1);
+})();
+
+
+(function testRestParamssloppyModeApply() {
+  sloppyTest.apply(null, []);
+  sloppyTest.apply(null, [2, 1]);
+  sloppyTest.apply(null, [6, 5, 4, 3, 2, 1]);
+  sloppyTest.apply(null, [3, 2, 1]);
+  O.sloppy.apply(O, []);
+  O.sloppy.apply(O, [2, 1]);
+  O.sloppy.apply(O, [6, 5, 4, 3, 2, 1]);
+  O.sloppy.apply(O, [3, 2, 1]);
+})();
+
+
+(function testRestParamssloppyModeCall() {
+  sloppyTest.call(null);
+  sloppyTest.call(null, 2, 1);
+  sloppyTest.call(null, 6, 5, 4, 3, 2, 1);
+  sloppyTest.call(null, 3, 2, 1);
+  O.sloppy.call(O);
+  O.sloppy.call(O, 2, 1);
+  O.sloppy.call(O, 6, 5, 4, 3, 2, 1);
+  O.sloppy.call(O, 3, 2, 1);
+})();
+
+
+(function testUnmappedArguments() {
+  // Normal functions make their arguments object unmapped, but arrow
+  // functions don't have an arguments object anyway.  Check that the
+  // right thing happens for arguments in arrow functions with rest
+  // parameters.
+  assertSame(arguments, ((...rest) => arguments)());
+})();