在 Angular 2 中编写最基本的单元测试？

Posted 2023-02-22

【中文标题】在 Angular 2 中编写最基本的单元测试？

【英文标题】：Writing the most basic Unit test in Angular 2?

【发布时间】：2015-08-28 22:53:40

【问题描述】：

问题：我将Angular 2 导入文件后，我的任何测试都不会执行。

问题：如何设置我的 karma 配置以支持 Angular 2，以便我的测试正确通过？

或 问题：如何使用 es6 编写的 angular2 设置任何测试框架？

Git Repo (make sure you're on branch angular-2

业力：

// Karma configuration
// Generated on Mon Jun 01 2015 14:16:41 GMT-0700 (PDT)

module.exports = function(config) 
  config.set(

    // base path that will be used to resolve all patterns (eg. files, exclude)
    basePath: '',

    // frameworks to use
    // available frameworks: https://npmjs.org/browse/keyword/karma-adapter
    frameworks: ['jspm', 'jasmine'],

    // list of files / patterns to load in the browser
    jspm: 
        loadFiles: [
            'client/app/**/*.js'
        ]
    ,

    // list of files to exclude

    plugins:[
            'karma-jasmine',
            'karma-coverage',
            'karma-jspm',
            'karma-chrome-launcher'
        ],


    // list of files to exclude
    exclude: [
    ],

    // preprocess matching files before serving them to the browser
    // available preprocessors: https://npmjs.org/browse/keyword/karma-preprocessor
    preprocessors: 
    ,

    // test results reporter to use
    // possible values: 'dots', 'progress'
    // available reporters: https://npmjs.org/browse/keyword/karma-reporter
    reporters: ['progress'],

    // web server port
    port: 9876,

    // enable / disable colors in the output (reporters and logs)
    colors: true,

    // level of logging
    // possible values: config.LOG_DISABLE || config.LOG_ERROR || config.LOG_WARN || config.LOG_INFO || config.LOG_DEBUG
    logLevel: config.LOG_INFO,

    // enable / disable watching file and executing tests whenever any file changes
    autoWatch: true,

    // start these browsers
    // available browser launchers: https://npmjs.org/browse/keyword/karma-launcher
    browsers: ['Chrome'],

    // Continuous Integration mode
    // if true, Karma captures browsers, runs the tests and exits
    singleRun: true
  );
;

JS：

"use strict";
import ComponentAnnotation as Component, ViewAnnotation as View from 'angular2/angular2';
import List from './list/list';

//@Component(selector: 'my-app')
//@View(template: `<h1>title</h1>`)
class Todo
    constructor()
        this.title = 'Gym';
        this.list = [new List()];
    

    setTitle(newTitle)
        this.title = newTitle;
    

    addListItem()
        this.list.push(new List());
    

    removeListItem()
        this.list.pop();
    

export default Todo;

Todo.spec.js：

import Todo from './todo';
describe('Todo list:', function()
    var todo;
    beforeEach(function()
        todo = new Todo();
    );

    it('expect Todo to be present', function()
        expect(todo).not.toBe(null);
    );

    it('expect Todo constructor to accept a title', function()
         expect(todo.title).toEqual('Gym');
    );

    it('expect Todo List property to be Present', function()
        expect(todo.list).not.toBe(null);
    )

    it('expect Todo List property to accept a title:empty', function()

         expect(todo.list[0].title).toEqual('empty');
    );

    it('expect Todo Title property to accept a title change', function()
         todo.setTitle('Work');
         expect(todo.title).toEqual('Work');
    );

    it('expect Todo List property to have an add function', function()
         todo.addListItem();
         expect(todo.list.length).toEqual(2);
    );

    it('expect Todo to have a remove function', function()
         todo.removeListItem();
         expect(todo.list.length).toEqual(0);
    )
);

预期错误：

$ karma start
INFO [karma]: Karma v0.12.36 server started at http://localhost:9876/
INFO [launcher]: Starting browser Chrome
WARN [web-server]: 404: /favicon.ico
INFO [Chrome 43.0.2357 (Mac OS X 10.10.3)]: Connected on socket 31YT5XsHM29BDG8sYXSq with id 13157663
Chrome 43.0.2357 (Mac OS X 10.10.3): Executed 0 of 0 ERROR (0.002 secs / 0 secs)

如果我删除 Todo.js 的角度导入

$ karma start
INFO [karma]: Karma v0.12.36 server started at http://localhost:9876/
INFO [launcher]: Starting browser Chrome
WARN [web-server]: 404: /favicon.ico
INFO [Chrome 43.0.2357 (Mac OS X 10.10.3)]: Connected on socket 7QKCB-7aTRwNsOGfYjmG with id 71239348
Chrome 43.0.2357 (Mac OS X 10.10.3): Executed 7 of 7 SUCCESS (0.008 secs / 0.005 secs)

从 GITTER 更新：

@matthewharwood 尝试将捆绑的 ng2 文件加载到您的 jspm Loadfiles 部分。使用 karma-jspm 插件，您可以指定自定义路径，因此您可以覆盖 angular/angular 路径以指向该单个捆绑文件。它使我们的测试运行起来更加容易。我还必须包含 karma babel 预处理器并通过它运行我的代码。

不幸的是，我无法让加载文件正常工作：c

【参考方案1】：

打开调试页面后，您可以看到 angular 告诉您它缺少 reflect-metadata 包。所以我在app/todo/todo.js 中添加了一个手动导入语句，它解决了这个问题：

import Reflect from 'reflect-metadata'
import  ComponentAnnotation as Component, ViewAnnotation as View  from 'angular2/angular2';
import List from './list/list';

我现在的输出是：

node_modules/.bin/karma start --single-run
INFO [karma]: Karma v0.12.36 server started at http://localhost:9876/
INFO [launcher]: Starting browser Chrome
WARN [web-server]: 404: /favicon.ico
INFO [Chrome 43.0.2357 (Mac OS X 10.10.3)]: Connected on socket cGnqva8p5bf-j7L2EVzI with id 94803307
Chrome 43.0.2357 (Mac OS X 10.10.3): Executed 7 of 7 SUCCESS (0.005 secs / 0.004 secs)