Babel 6 – asynchronous箭头function“this”指向function
巴别塔6与这些设置
require("babel-register")({ extensions: [".es6", ".es", ".jsx", ".js"], plugins: ['transform-runtime'], presets: ["es2015", "stage-0"] }); 意想不到的是，这个引用在普通的箭头函数和asynchronous的箭头函数之间是不同的。 所以我的问题真的是，别人可以确认这是一个与最新的巴贝尔的错误，我应该在哪里报告这个问题。
class TestClass { name = "John Doe"; testMethodSuccess() { return new Promise((resolve) => { console.log(this); setTimeout(resolve, 1000); }); } testMethodFailure() { return new Promise(async (resolve) => { console.log(this); setTimeout(resolve, 1000); }); } } (async () => { try{ var testObject = new TestClass(); await testObject.testMethodSuccess(); await testObject.testMethodFailure(); }catch(e){ console.error(e); } })();
这是上面的代码的结果
"use strict"; var _regenerator = require("babel-runtime/regenerator"); var _regenerator2 = _interopRequireDefault(_regenerator); var _asyncToGenerator2 = require("babel-runtime/helpers/asyncToGenerator"); var _asyncToGenerator3 = _interopRequireDefault(_asyncToGenerator2); var _promise = require("babel-runtime/core-js/promise"); var _promise2 = _interopRequireDefault(_promise); var _classCallCheck2 = require("babel-runtime/helpers/classCallCheck"); var _classCallCheck3 = _interopRequireDefault(_classCallCheck2); var _createClass2 = require("babel-runtime/helpers/createClass"); var _createClass3 = _interopRequireDefault(_createClass2); function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; } var TestClass = function () { function TestClass() { (0, _classCallCheck3.default)(this, TestClass); this.name = "John Doe"; } (0, _createClass3.default)(TestClass, [{ key: "testMethodSuccess", value: function testMethodSuccess() { var _this = this; return new _promise2.default(function (resolve) { console.log(_this); setTimeout(resolve, 1000); }); } }, { key: "testMethodFailure", value: function testMethodFailure() { return new _promise2.default(function () { var _this2 = this; var ref = (0, _asyncToGenerator3.default)(_regenerator2.default.mark(function _callee(resolve) { return _regenerator2.default.wrap(function _callee$(_context) { while (1) { switch (_context.prev = _context.next) { case 0: console.log(_this2); setTimeout(resolve, 1000); case 2: case "end": return _context.stop(); } } }, _callee, _this2); })); return function (_x) { return ref.apply(this, arguments); }; }()); } }]); return TestClass; }(); (0, _asyncToGenerator3.default)(_regenerator2.default.mark(function _callee2() { var testObject; return _regenerator2.default.wrap(function _callee2$(_context2) { while (1) { switch (_context2.prev = _context2.next) { case 0: _context2.prev = 0; testObject = new TestClass(); _context2.next = 4; return testObject.testMethodSuccess(); case 4: _context2.next = 6; return testObject.testMethodFailure(); case 6: _context2.next = 11; break; case 8: _context2.prev = 8; _context2.t0 = _context2["catch"](0); console.error(_context2.t0); case 11: case "end": return _context2.stop(); } } }, _callee2, undefined, [[0, 8]]);