From a2e16768674ab156c9312def535b3dcc51ebf1e7 Mon Sep 17 00:00:00 2001 From: Xotic750 Date: Sun, 15 Nov 2015 20:44:10 +0100 Subject: [PATCH] Fix `Function.prototype.call` and tests. Ref: https://github.com/es-shims/es5-shim/issues/304 Changed some code back as mentioned in comments. Changed more code as per comments Changed more code as per comments. Changed some variable names to better reflect comments. Fixed missed invocation. Added some comments and code changes as discussed. [tests] Remove unneeded jshint comment. [Tests] use the preferred it/skip pattern for this strict mode test. https://github.com/es-shims/es5-shim/pull/345#discussion_r44878834 And some other cleanup Added `arguments` expectations to tests. Add tests for `Object#toString` of typed arrays and Symbols, if they exist. Added note about typed array tests. Fix `hasToStringTagRegExpBug` Removed RegExp and Array bug detection as can not test, possible Opera 9. Fixed missing `force` on `defineProperties` that caused the patch to not be applied on IE<9. Fixed `Uint8ClampedArray` tests for Opera 11 and IE10 that don't have it. Removed offending test that was moved to detection, but forgotten. Avoid all possibilities of `call` calling `call`. Do not pass `undefined` argument, we know IE<9 has unfixable bug. Final cleanup (hopeully) Port over work from `apply` fix Move code so that it is specific to the fix. Robustness, move before bind. Remove `Array#slice` tests. Add notes about `eval` and `apply` avoidance. --- es5-shim.js | 66 +++++++++++++++++++++++++++++++- tests/spec/s-array.js | 19 +++++----- tests/spec/s-function.js | 81 +++++++++++++++++++++++++++++++++++++++- tests/spec/s-object.js | 68 ++++++++++++++++++++++++++++++++- 4 files changed, 218 insertions(+), 16 deletions(-) diff --git a/es5-shim.js b/es5-shim.js index e9aa3474..d92fc282 100644 --- a/es5-shim.js +++ b/es5-shim.js @@ -56,6 +56,7 @@ var array_push = ArrayPrototype.push; var array_unshift = ArrayPrototype.unshift; var array_concat = ArrayPrototype.concat; var call = FunctionPrototype.call; +var apply = FunctionPrototype.apply; var max = Math.max; var min = Math.min; @@ -163,7 +164,6 @@ var ES = { // http://es5.github.com/#x9.9 /* replaceable with https://npmjs.com/package/es-abstract ES5.ToObject */ ToObject: function (o) { - /* jshint eqnull: true */ if (o == null) { // this matches both null and undefined throw new TypeError("can't convert " + o + ' to object'); } @@ -181,6 +181,68 @@ var ES = { // ======== // +// Tests for inconsistent or buggy `[[Class]]` strings. +/* eslint-disable no-useless-call */ +var hasToStringTagBasicBug = to_string.call() !== '[object Undefined]' || to_string.call(null) !== '[object Null]'; +/* eslint-enable no-useless-call */ +var hasToStringTagLegacyArguments = to_string.call(arguments) !== '[object Arguments]'; +var hasToStringTagInconsistency = hasToStringTagBasicBug || hasToStringTagLegacyArguments; +// Others that could be fixed: +// Older ES3 native functions like `alert` return `[object Object]`. +// Inconsistent `[[Class]]` strings for `window` or `global`. + +if (hasToStringTagInconsistency) { + // To prevent recursion when `Function#call` is patched. Robustness. + call.call = call; +} + +if (hasToStringTagLegacyArguments) { + // This function is for use within `call` only. + // To avoid any possibility of `call` recursion we use original `hasOwnProperty`. + var isDuckTypeArguments = (function (hasOwnProperty) { + return function (value) { + return value != null && // Checks `null` or `undefined`. + typeof value === 'object' && + call.call(hasOwnProperty, value, 'length') && + typeof value.length === 'number' && + value.length >= 0 && + !call.call(hasOwnProperty, value, 'arguments') && + call.call(hasOwnProperty, value, 'callee'); + // Using `isCallable` here is dangerous as it can cause recursion. + // Unless modified to use `call.call`. + // A typeof check would be ok if necessary. + }; + }(ObjectPrototype.hasOwnProperty)); +} + +// ES-5 15.3.4.4 +// http://es5.github.io/#x15.3.4.4 +// The call() method calls a function with a given this value and arguments +// provided individually. +defineProperties(FunctionPrototype, { + call: function (thisArg) { + // If `this` is `Object#toString`. + if (this === to_string) { + // Add whatever fixes for getting `[[Class]]` strings here. + if (thisArg === null) { + return '[object Null]'; + } + if (typeof thisArg === 'undefined') { + return '[object Undefined]'; + } + if (hasToStringTagLegacyArguments && isDuckTypeArguments(thisArg)) { + return '[object Arguments]'; + } + return call.call(to_string, thisArg); + } + // All other calls. + // `array_slice` is safe to use here, no known issue at present. + // Could probably use eval/Function here to spread the arguments, then use + // `call.call` to avoid `apply` altogether. + return this.apply(thisArg, call.call(array_slice, arguments, 1)); + } +}, hasToStringTagInconsistency); + // ES-5 15.3.4.5 // http://es5.github.com/#x15.3.4.5 @@ -321,7 +383,7 @@ defineProperties(FunctionPrototype, { }); // _Please note: Shortcuts are defined after `Function.prototype.bind` as we -// us it in defining shortcuts. +// use it in defining shortcuts. var owns = call.bind(ObjectPrototype.hasOwnProperty); var toStr = call.bind(ObjectPrototype.toString); var strSlice = call.bind(StringPrototype.slice); diff --git a/tests/spec/s-array.js b/tests/spec/s-array.js index f128d943..6077b127 100644 --- a/tests/spec/s-array.js +++ b/tests/spec/s-array.js @@ -9,6 +9,7 @@ var hasStrictMode = (function () { return !this; }()); +var ifHasStrictIt = hasStrictMode ? it : xit; describe('Array', function () { var testSubject; @@ -123,17 +124,15 @@ describe('Array', function () { expect(toStr.call(listArg)).toBe('[object String]'); }); - if (hasStrictMode) { - it('does not autobox the content in strict mode', function () { - var context; - [1].forEach(function () { - 'use strict'; + ifHasStrictIt('does not autobox the content in strict mode', function () { + var context; + [1].forEach(function () { + 'use strict'; - context = this; - }, 'x'); - expect(typeof context).toBe('string'); - }); - } + context = this; + }, 'x'); + expect(typeof context).toBe('string'); + }); }); describe('#some()', function () { var actual, expected, numberOfRuns; diff --git a/tests/spec/s-function.js b/tests/spec/s-function.js index 97237adb..5fa4bfe1 100644 --- a/tests/spec/s-function.js +++ b/tests/spec/s-function.js @@ -1,7 +1,84 @@ -/* global describe, it, expect, beforeEach */ +/* global describe, it, xit, expect, beforeEach */ +var hasStrictMode = (function () { + 'use strict'; + + return !this; +}()); +var ifHasStrictIt = hasStrictMode ? it : xit; +var global = Function('return this')(); describe('Function', function () { - 'use strict'; + describe('#call()', function () { + it('should pass correct arguments', function () { + // https://github.com/es-shims/es5-shim/pull/345#discussion_r44878754 + var result; + var testFn = function () { + return Array.prototype.slice.call(arguments); + }; + var argsExpected = [null, '1', 1, true, testFn]; + /* eslint-disable no-useless-call */ + result = testFn.call(undefined, null, '1', 1, true, testFn); + expect(result).toEqual(argsExpected); + result = testFn.call(null, null, '1', 1, true, testFn); + expect(result).toEqual(argsExpected); + /* eslint-enable no-useless-call */ + result = testFn.call('a', null, '1', 1, true, testFn); + expect(result).toEqual(argsExpected); + result = testFn.call(1, null, '1', 1, true, testFn); + expect(result).toEqual(argsExpected); + result = testFn.call(true, null, '1', 1, true, testFn); + expect(result).toEqual(argsExpected); + result = testFn.call(testFn, null, '1', 1, true, testFn); + expect(result).toEqual(argsExpected); + result = testFn.call(new Date(), null, '1', 1, true, testFn); + expect(result).toEqual(argsExpected); + }); + // https://github.com/es-shims/es5-shim/pull/345#discussion_r44878771 + ifHasStrictIt('should have correct context in strict mode', function () { + 'use strict'; + + var subject; + var testFn = function () { + return this; + }; + expect(testFn.call()).toBe(undefined); + /* eslint-disable no-useless-call */ + expect(testFn.call(undefined)).toBe(undefined); + expect(testFn.call(null)).toBe(null); + /* eslint-enable no-useless-call */ + expect(testFn.call('a')).toBe('a'); + expect(testFn.call(1)).toBe(1); + expect(testFn.call(true)).toBe(true); + expect(testFn.call(testFn)).toBe(testFn); + subject = new Date(); + expect(testFn.call(subject)).toBe(subject); + }); + it('should have correct context in non-strict mode', function () { + var result; + var subject; + var testFn = function () { + return this; + }; + + expect(testFn.call()).toBe(global); + /* eslint-disable no-useless-call */ + expect(testFn.call(undefined)).toBe(global); + expect(testFn.call(null)).toBe(global); + /* eslint-enable no-useless-call */ + result = testFn.call('a'); + expect(typeof result).toBe('object'); + expect(String(result)).toBe('a'); + result = testFn.call(1); + expect(typeof result).toBe('object'); + expect(Number(result)).toBe(1); + result = testFn.call(true); + expect(typeof result).toBe('object'); + expect(Boolean(result)).toBe(true); + expect(testFn.call(testFn)).toBe(testFn); + subject = new Date(); + expect(testFn.call(subject)).toBe(subject); + }); + }); describe('#apply()', function () { it('works with arraylike objects', function () { diff --git a/tests/spec/s-object.js b/tests/spec/s-object.js index c17f1bde..4fbac096 100644 --- a/tests/spec/s-object.js +++ b/tests/spec/s-object.js @@ -1,4 +1,6 @@ -/* global describe, it, xit, expect, beforeEach, jasmine, window */ +/* global describe, it, xit, expect, beforeEach, jasmine, window, + ArrayBuffer, Float32Array, Float64Array, Int8Array, Int16Array, + Int32Array, Uint8Array, Uint8ClampedArray, Uint16Array, Uint32Array */ var ifWindowIt = typeof window === 'undefined' ? xit : it; var extensionsPreventible = typeof Object.preventExtensions === 'function' && (function () { @@ -22,7 +24,14 @@ var canFreeze = typeof Object.freeze === 'function' && (function () { return obj.a !== 3; }()); var ifCanFreezeIt = canFreeze ? it : xit; - +var toStr = Object.prototype.toString; +var noop = function () {}; +var hasIteratorTag = typeof Symbol === 'function' && typeof Symbol.iterator === 'symbol'; +var ifHasIteratorTag = hasIteratorTag ? it : xit; +var hasArrayBuffer = typeof ArrayBuffer === 'function'; +var ifHasArrayBuffer = hasArrayBuffer ? it : xit; +var hasUint8ClampedArray = typeof Uint8ClampedArray === 'function'; +var ifHasUint8ClampedArray = hasUint8ClampedArray ? it : xit; describe('Object', function () { 'use strict'; @@ -356,4 +365,59 @@ describe('Object', function () { expect(obj instanceof Object).toBe(false); }); }); + + describe('#toString', function () { + it('basic', function () { + expect(toStr.call()).toBe('[object Undefined]'); + /* eslint-disable no-useless-call */ + expect(toStr.call(undefined)).toBe('[object Undefined]'); + expect(toStr.call(null)).toBe('[object Null]'); + /* eslint-enable no-useless-call */ + expect(toStr.call(1)).toBe('[object Number]'); + expect(toStr.call(true)).toBe('[object Boolean]'); + expect(toStr.call('x')).toBe('[object String]'); + expect(toStr.call([1, 2, 3])).toBe('[object Array]'); + expect(toStr.call(arguments)).toBe('[object Arguments]'); + expect(toStr.call({})).toBe('[object Object]'); + expect(toStr.call(noop)).toBe('[object Function]'); + expect(toStr.call(new RegExp('c'))).toBe('[object RegExp]'); + expect(toStr.call(new Date())).toBe('[object Date]'); + expect(toStr.call(new Error('x'))).toBe('[object Error]'); + }); + ifHasArrayBuffer('Typed Arrays', function () { + var buffer = new ArrayBuffer(8); + expect(toStr.call(buffer)).toBe('[object ArrayBuffer]'); + expect(toStr.call(new Float32Array(buffer))).toBe('[object Float32Array]'); + expect(toStr.call(new Float64Array(buffer))).toBe('[object Float64Array]'); + expect(toStr.call(new Int8Array(buffer))).toBe('[object Int8Array]'); + expect(toStr.call(new Int16Array(buffer))).toBe('[object Int16Array]'); + expect(toStr.call(new Int32Array(buffer))).toBe('[object Int32Array]'); + expect(toStr.call(new Uint8Array(buffer))).toBe('[object Uint8Array]'); + expect(toStr.call(new Uint16Array(buffer))).toBe('[object Uint16Array]'); + expect(toStr.call(new Uint32Array(buffer))).toBe('[object Uint32Array]'); + }); + ifHasUint8ClampedArray('Uint8ClampedArray', function () { + var buffer = new ArrayBuffer(8); + expect(toStr.call(new Uint32Array(buffer))).toBe('[object Uint32Array]'); + }); + ifHasIteratorTag('Symbol.iterator', function () { + expect(toStr.call(Symbol.iterator)).toBe('[object Symbol]'); + }); + // https://github.com/es-shims/es5-shim/pull/345#discussion_r44878834 + it('prototypes', function () { + expect(toStr.call(Object.prototype)).toBe('[object Object]'); + expect(toStr.call(Array.prototype)).toBe('[object Array]'); + expect(toStr.call(Boolean.prototype)).toBe('[object Boolean]'); + expect(toStr.call(Function.prototype)).toBe('[object Function]'); + }); + // In ES6, many prototype objects stop being instances of themselves, + // and instead would return '[object Object]'. + xit('prototypes', function () { + expect(toStr.call(Number.prototype)).toBe('[object Number]'); + expect(toStr.call(String.prototype)).toBe('[object String]'); + expect(toStr.call(Error.prototype)).toBe('[object Error]'); + expect(toStr.call(Date.prototype)).toBe('[object Date]'); + expect(toStr.call(RegExp.prototype)).toBe('[object RegExp]'); + }); + }); });