ReferenceError：找不到变量：Map [英] ReferenceError: Can't find variable: Map
问题描述
我正在使用Angular 4，Webpack 2.4.1，Karma 1.6和Jasmine 2.6.1，我正在编写ES2015 不 TypeScript
I'm using Angular 4, Webpack 2.4.1, Karma 1.6 and Jasmine 2.6.1 and am writing ES2015 not TypeScript
我有一个小角度演示应用程序，我想添加单元测试。演示应用程序本身正在运行，Webpack正在捆绑所有内容，但是当我尝试运行单元测试时，我在控制台中看到一些错误，如下所示：
I've got a tiny angular demo app and I want to add unit tests. The demo app itself itself is working and Webpack is bundling everything correctly, but when I try to run the unit tests I see some errors in the console like this:
ReferenceError：在Static / js / app.welcome.js找不到变量：Map
ReferenceError: Can't find variable: Map
：2569
（ app.welcome.js 是我的组件的名称）
Webpack似乎正在构建我的测试包，Karma服务器正常启动并且PhantomJS正确启动，但后来我看到了几个Map错误。
Webpack appears to be building my test bundle properly, Karma server is starting up correctly and PhantomJS is launching correctly, but then I see several of the Map errors.
我是肯定在我自己的代码中没有使用 Map（）构造函数。
I'm definitely not using the Map() constructor in my own code.
以下是我的档案 -
Here are my files -
app.welcome.js ：
import {Component} from '@angular/core';
class WelcomeComponent {
constructor () {
this.welcomeMessage = 'Welcome to Angular 4';
}
}
WelcomeComponent.annotations = [
new Component({
selector: 'my-app',
template: '<h1>{{welcomeMessage}}</h1>'
})
];
export {WelcomeComponent};
app.welcome.spec.js ：
import {TestBed} from '@angular/core/testing';
import {WelcomeComponent} from '../../js/app.welcome';
describe('The Welcome component', function () {
let component;
beforeEach(function() {
TestBed.configureTestingModule({
declarations: [WelcomeComponent]
});
const fixture = TestBed.createComponent(WelcomeComponent);
component = fixture.componentInstance;
});
it('should be a component', function() {
expect(component).toBeDefined();
});
it('should have a welcome message', function () {
expect(component.welcomeMessage).toEqual('Welcome to Angular 4');
});
});
karma.conf.js ：
const webpack = require('webpack');
module.exports = function(config) {
config.set({
basePath: '',
frameworks: ['jasmine'],
files: [
'./Static/js/**/*.js',
'./Static/test/**/*.spec.js'
],
exclude: [
'./Static/js/main.js'
],
preprocessors: {
'./Static/js/**/*.js': ['webpack'],
'./Static/test/**/*.spec.js': ['webpack']
},
reporters: ['progress'],
port: 9876,
colors: true,
logLevel: config.LOG_INFO,
autoWatch: false,
browsers: ['PhantomJS'],
singleRun: true,
concurrency: Infinity,
webpack: {
module: {
rules: [{
test: /\.js$/,
use: [{
loader: 'babel-loader',
options: { presets: ['es2015'] }
}]
}]
},
plugins: [
new webpack.ContextReplacementPlugin(/angular(\\|\/)core(\\|\/)@angular/, './src')
]
}
})
}
我尝试将导入添加到我的测试文件喜欢导入'zone.js'; 和导入'core-js / es6'; 在阅读其他答案后，但这没有帮助。
I've tried adding imports to my test file like import 'zone.js'; and import 'core-js/es6'; after reading other answers here, but this has not helped.
我看了 Testing -ts - GUIDE 我似乎没有遗漏任何早期基本示例中的任何内容，但问题是所有的官方文档面向TypeScript，而我想使用ES2015。
I've looked through Testing -ts - GUIDE and I don't appear to be missing anything huge from the earlier basic examples, but the problem is that all the official docs are geared towards TypeScript, while I want to use ES2015.
我知道Map是ES2015中的一种新类型的对象，而不是错误所指示的变量。 Babel不应该支持这个吗？
I understand that Map is an new type of object in ES2015 and not a variable as indicated by the error. Shouldn't Babel support this though?
任何人都可以帮忙吗？
推荐答案
抛出此错误是因为浏览器中没有 Map 。 PhantomJS用作Karma驱动程序，它不支持ES6功能。
This error is thrown because there's no Map in browsers. PhantomJS is used as Karma driver, and it doesn't support ES6 features.
如果polyfills（例如 core-js ）没有加载到测试中包含的文件中，它们应该单独加载，例如通过 karma-es6-shim 插件：
If polyfills (e.g. core-js) aren't loaded in files that were included in tests, they should be loaded separately, for example via karma-es6-shim plugin:
...
frameworks: ['es6-shim', 'jasmine'],
...
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