From fa7ec817718aeba43d554999e23d59b4e88a5fe0 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Nicol=C3=B2=20Ribaudo?= Date: Thu, 19 Mar 2020 11:02:12 +0100 Subject: [PATCH] Allow for-of on polyfilled or builtin iterables without `Symbol` support (#11285) --- packages/babel-helpers/src/helpers.js | 8 ++++++-- .../loose-exec/arguments-symbol-unsupported.js | 18 ++++++++++++++++++ .../spec-exec/arguments-symbol-unsupported.js | 18 ++++++++++++++++++ .../sanity/block-scoping-for-of/output.js | 10 +++++----- 4 files changed, 47 insertions(+), 7 deletions(-) create mode 100644 packages/babel-plugin-transform-for-of/test/fixtures/loose-exec/arguments-symbol-unsupported.js create mode 100644 packages/babel-plugin-transform-for-of/test/fixtures/spec-exec/arguments-symbol-unsupported.js diff --git a/packages/babel-helpers/src/helpers.js b/packages/babel-helpers/src/helpers.js index 44ce01583a7a..d008cce43af5 100644 --- a/packages/babel-helpers/src/helpers.js +++ b/packages/babel-helpers/src/helpers.js @@ -1072,6 +1072,8 @@ helpers.nonIterableRest = helper("7.0.0-beta.0")` `; helpers.createForOfIteratorHelper = helper("7.9.0")` + import unsupportedIterableToArray from "unsupportedIterableToArray"; + // s: start (create the iterator) // n: next // e: error (called whenever something throws) @@ -1080,7 +1082,7 @@ helpers.createForOfIteratorHelper = helper("7.9.0")` export default function _createForOfIteratorHelper(o) { if (typeof Symbol === "undefined" || o[Symbol.iterator] == null) { // Fallback for engines without symbol support - if (Array.isArray(o)) { + if (Array.isArray(o) || (o = unsupportedIterableToArray(o))) { var i = 0; var F = function(){}; return { @@ -1124,12 +1126,14 @@ helpers.createForOfIteratorHelper = helper("7.9.0")` `; helpers.createForOfIteratorHelperLoose = helper("7.9.0")` + import unsupportedIterableToArray from "unsupportedIterableToArray"; + export default function _createForOfIteratorHelperLoose(o) { var i = 0; if (typeof Symbol === "undefined" || o[Symbol.iterator] == null) { // Fallback for engines without symbol support - if (Array.isArray(o)) + if (Array.isArray(o) || (o = unsupportedIterableToArray(o))) return function() { if (i >= o.length) return { done: true }; return { done: false, value: o[i++] }; diff --git a/packages/babel-plugin-transform-for-of/test/fixtures/loose-exec/arguments-symbol-unsupported.js b/packages/babel-plugin-transform-for-of/test/fixtures/loose-exec/arguments-symbol-unsupported.js new file mode 100644 index 000000000000..d8c9899f8d99 --- /dev/null +++ b/packages/babel-plugin-transform-for-of/test/fixtures/loose-exec/arguments-symbol-unsupported.js @@ -0,0 +1,18 @@ +function getArgs() { return arguments; } + +let args = getArgs(1, 2, 3); +let res = []; + +// Simulate old environment +delete args[Symbol.iterator]; +let _Symbol = Symbol; +Symbol = void 0; + +try { + for (let i of args) res.push(i); + + expect(res).toEqual([1, 2, 3]); +} finally { + Symbol = _Symbol; +} + diff --git a/packages/babel-plugin-transform-for-of/test/fixtures/spec-exec/arguments-symbol-unsupported.js b/packages/babel-plugin-transform-for-of/test/fixtures/spec-exec/arguments-symbol-unsupported.js new file mode 100644 index 000000000000..d8c9899f8d99 --- /dev/null +++ b/packages/babel-plugin-transform-for-of/test/fixtures/spec-exec/arguments-symbol-unsupported.js @@ -0,0 +1,18 @@ +function getArgs() { return arguments; } + +let args = getArgs(1, 2, 3); +let res = []; + +// Simulate old environment +delete args[Symbol.iterator]; +let _Symbol = Symbol; +Symbol = void 0; + +try { + for (let i of args) res.push(i); + + expect(res).toEqual([1, 2, 3]); +} finally { + Symbol = _Symbol; +} + diff --git a/packages/babel-preset-env/test/fixtures/sanity/block-scoping-for-of/output.js b/packages/babel-preset-env/test/fixtures/sanity/block-scoping-for-of/output.js index 8659fc16330d..8deec063a326 100644 --- a/packages/babel-preset-env/test/fixtures/sanity/block-scoping-for-of/output.js +++ b/packages/babel-preset-env/test/fixtures/sanity/block-scoping-for-of/output.js @@ -2,15 +2,15 @@ function _slicedToArray(arr, i) { return _arrayWithHoles(arr) || _iterableToArra function _nonIterableRest() { throw new TypeError("Invalid attempt to destructure non-iterable instance.\nIn order to be iterable, non-array objects must have a [Symbol.iterator]() method."); } -function _unsupportedIterableToArray(o, minLen) { if (!o) return; if (typeof o === "string") return _arrayLikeToArray(o, minLen); var n = Object.prototype.toString.call(o).slice(8, -1); if (n === "Object" && o.constructor) n = o.constructor.name; if (n === "Map" || n === "Set") return Array.from(n); if (n === "Arguments" || /^(?:Ui|I)nt(?:8|16|32)(?:Clamped)?Array$/.test(n)) return _arrayLikeToArray(o, minLen); } - -function _arrayLikeToArray(arr, len) { if (len == null || len > arr.length) len = arr.length; for (var i = 0, arr2 = new Array(len); i < len; i++) { arr2[i] = arr[i]; } return arr2; } - function _iterableToArrayLimit(arr, i) { if (typeof Symbol === "undefined" || !(Symbol.iterator in Object(arr))) return; var _arr = []; var _n = true; var _d = false; var _e = undefined; try { for (var _i = arr[Symbol.iterator](), _s; !(_n = (_s = _i.next()).done); _n = true) { _arr.push(_s.value); if (i && _arr.length === i) break; } } catch (err) { _d = true; _e = err; } finally { try { if (!_n && _i["return"] != null) _i["return"](); } finally { if (_d) throw _e; } } return _arr; } function _arrayWithHoles(arr) { if (Array.isArray(arr)) return arr; } -function _createForOfIteratorHelper(o) { if (typeof Symbol === "undefined" || o[Symbol.iterator] == null) { if (Array.isArray(o)) { var i = 0; var F = function F() {}; return { s: F, n: function n() { if (i >= o.length) return { done: true }; return { done: false, value: o[i++] }; }, e: function e(_e) { throw _e; }, f: F }; } throw new TypeError("Invalid attempt to iterate non-iterable instance.\nIn order to be iterable, non-array objects must have a [Symbol.iterator]() method."); } var it, normalCompletion = true, didErr = false, err; return { s: function s() { it = o[Symbol.iterator](); }, n: function n() { var step = it.next(); normalCompletion = step.done; return step; }, e: function e(_e2) { didErr = true; err = _e2; }, f: function f() { try { if (!normalCompletion && it["return"] != null) it["return"](); } finally { if (didErr) throw err; } } }; } +function _createForOfIteratorHelper(o) { if (typeof Symbol === "undefined" || o[Symbol.iterator] == null) { if (Array.isArray(o) || (o = _unsupportedIterableToArray(o))) { var i = 0; var F = function F() {}; return { s: F, n: function n() { if (i >= o.length) return { done: true }; return { done: false, value: o[i++] }; }, e: function e(_e) { throw _e; }, f: F }; } throw new TypeError("Invalid attempt to iterate non-iterable instance.\nIn order to be iterable, non-array objects must have a [Symbol.iterator]() method."); } var it, normalCompletion = true, didErr = false, err; return { s: function s() { it = o[Symbol.iterator](); }, n: function n() { var step = it.next(); normalCompletion = step.done; return step; }, e: function e(_e2) { didErr = true; err = _e2; }, f: function f() { try { if (!normalCompletion && it["return"] != null) it["return"](); } finally { if (didErr) throw err; } } }; } + +function _unsupportedIterableToArray(o, minLen) { if (!o) return; if (typeof o === "string") return _arrayLikeToArray(o, minLen); var n = Object.prototype.toString.call(o).slice(8, -1); if (n === "Object" && o.constructor) n = o.constructor.name; if (n === "Map" || n === "Set") return Array.from(n); if (n === "Arguments" || /^(?:Ui|I)nt(?:8|16|32)(?:Clamped)?Array$/.test(n)) return _arrayLikeToArray(o, minLen); } + +function _arrayLikeToArray(arr, len) { if (len == null || len > arr.length) len = arr.length; for (var i = 0, arr2 = new Array(len); i < len; i++) { arr2[i] = arr[i]; } return arr2; } // https://github.com/babel/babel/issues/7557 var _iterator = _createForOfIteratorHelper(c),