Web自动化之Headless Chrome测试框架集成

使用Selenium操作headless chrome 推荐

简介

WebDriver是一个W3C标准, 定义了一套检查和控制用户代理（比如浏览器）的远程控制接口，各大主流浏览器来实现这些接口以便调用控制接口来操作浏览器。

Selenium是一整套的Web自动化测试解决方案，配合WebDrive规范，实现了对各种用户代理的适配（比如浏览器,PhantomJS等），通过操作浏览器的WebDriver接口来实现带浏览器的Web自动化。

使用selenium-webdriver

selenium相关的API文档selenium-webdriver的JavaScriptAPI文档 const webdriver = require('selenium-webdriver'), By = webdriver.By; const driver = new webdriver.Builder() .forBrowser('chrome') .build(); driver.get('https://www.baidu.com').then((args) => { // 获取百度搜索按钮的 文本 driver.findElement(By.id('su')).then((element) => { return element.getAttribute('value') }).then((btnName) => { console.log(btnName) }); // 获取百度首页 title driver.getTitle().then((title) => { console.log(title); }); }); driver.quit();

使用browserstack-webdriver

只是获取driver的方式不一样，其他调用完全一样

const webdriver = require('browserstack-webdriver'), By = webdriver.By; // Input capabilities const capabilities = { 'browserName' : 'firefox', 'browserstack.user' : BROWSERSTACK_USERNAME, 'browserstack.key' : BROWSERSTACK_KEY } const driver = new webdriver.Builder(). usingServer('http://hub.browserstack.com/wd/hub'). withCapabilities(capabilities). build(); driver.get('https://www.baidu.com').then((args) => { // 获取百度搜索按钮的 文本 driver.findElement(By.id('su')).then((element) => { return element.getAttribute('value') }).then((btnName) => { console.log(btnName) }); // 获取百度首页 title driver.getTitle().then((title) => { console.log(title); }); }); driver.quit();

使用 chromedriver

chromedriver是一个编码辅助，自动配置环境变量，不需要手动下载和配置环境变量，通过安装chromedriver同时在代码中引入

require('chromedriver')

更换获取源的URL（使用如下任意一种就行）

安装过程添加参数，默认下载地址为http://chromedriver.storage.googleapis.com

npm install chromedriver --chromedriver_cdnurl=https://npm.taobao.org/mirrors/chromedriver

添加如下内容到.npmrc文件

chromedriver_cdnurl=https://npm.taobao.org/mirrors/chromedriver 添加环境变量CHROMEDRIVER_CDNURL CHROMEDRIVER_CDNURL=https://npm.taobao.org/mirrors/chromedriver npm install chromedriver

更换安装的chromedriver文件路径

安装过程使用配置参数 npm install chromedriver --chromedriver_filepath=/path/to/chromedriver_mac64.zip 添加如下内容到.npmrc文件 chromedriver_filepath=/path/to/chromedriver_mac64.zip 添加环境变量 CHROMEDRIVER_FILEPATH=/path/to/chromedriver_mac64.zip

使用mocha + chai

简介

mocha是一个可以运行在浏览器端和NodeJS环境的JavaScript测试框架，区别于类库，框架定义好了流程，并调用你的代码。

chai是一个断言库，判断结果是否符合预期。

实例代码

const chai = require('chai'); const chromeDriver = require('selenium-webdriver/chrome') const webdriver = require('selenium-webdriver'), By = webdriver.By; const driver = new webdriver.Builder() .forBrowser('chrome') .setChromeOptions(new chromeDriver.Options().addArguments(['headless'])) .build(); describe('首页加载测试',function(){ // 获取百度搜索按钮的 文本 describe('按钮文本',function(){ it('按钮文本必须等于',function(done){ driver.get('https://www.baidu.com').then(function(){ driver.findElement(By.id('su')).then((element) => { return element.getAttribute('value') }).then((btnName) => { console.log(btnName); chai.expect(btnName).to.equal('百度一下'); done(); }); }); }) }); // 获取百度首页 title describe('首页标题',function(){ it('首页标题应该为',function(done){ driver.get('https://www.baidu.com').then(function(){ driver.getTitle().then((title) => { console.log(title); chai.expect(title).to.equal('百度一下，你就知道'); done(); }); }); }); }); after(function(){ driver.quit(); }) });

使用Karma + mocha + chai

简介

Karma是一个用JavaScript实现的测试执行器，实现了如下内容

对各种常见框架、库的适配参考各种常见代码预处理或转译参考各种执行的测试报告方案参考各种浏览器或类浏览器的适配参考各种编辑器的适配，内容变更，立即重新执行覆盖率统计

安装相应的依赖库

npm i --save-dev karma karma-chrome-launcher karma-mocha karma-chai npm i --save-dev mocha chai

生成配置文件

在工程目录下执行如下命令

./node_modules/.bin/karma init

一路按照提示操作即可，生成的配置文件在工程目录下karma.conf.js，内容大致如下：

// Karma configuration // Generated on Mon Jul 10 2017 19:49:48 GMT+0800 (CST) 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: ['mocha'], // list of files / patterns to load in the browser files: [ ], // 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: false, // Concurrency level // how many browser should be started simultaneous concurrency: Infinity }) }

调整配置支持headless chrome

可以到这里,查看chrome相关的karma-launcher，有ChromeHeadless和ChromeCanaryHeadless这两个headless驱动可以选择。

调整配置支持ES6，添加webpack

npm i webpack karma-webpack babel-core babel-loader babel-preset-es2015

调整配置增加测试覆盖度

npm i babel-plugin-istanbul

最终的到的Karma配置文件

karma.conf.js

// Karma configuration // Generated on Mon Jul 10 2017 19:49:48 GMT+0800 (CST) 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: ['mocha','chai'], // list of files / patterns to load in the browser files: [ 'test/**/*.js' ], // 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/**/*.js': ['webpack'] }, // test results reporter to use // possible values: 'dots', 'progress' // available reporters: https://npmjs.org/browse/keyword/karma-reporter reporters: ['progress', 'coverage'], coverageReporter: { type: 'html', dir: 'coverage/' }, // 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: ['ChromeHeadless'], // Continuous Integration mode // if true, Karma captures browsers, runs the tests and exits singleRun: true, // Concurrency level // how many browser should be started simultaneous concurrency: Infinity, webpack: { module: { loaders: [{ test: /\.js$/, loader: 'babel-loader', exclude: /node_modules/, query: { presets: ['es2015'], plugins: ['istanbul'] } }] } } }) }

编写代码

src/index.js

const isType = (data, type) => { return ['[object ', type, ']'].join('') === Object.prototype.toString.call(data) }; const isFunction = (data) => { return isType(data, 'Function') }; const isArray = (data) => { return isType(data, 'Array') }; module.exports = { isType, isFunction, isArray }

编写测试用例

test/index.js

const typeUtil = require('../src/index') describe('index.js: ', () => { it('isFunction() should work fine.', () => { expect(typeUtil.isFunction(function(){})).to.equal(true) expect(typeUtil.isFunction(Object.prototype.toString)).to.equal(true) }); it('isArray() should work file.', () => { expect(typeUtil.isArray([])).to.equal(true) expect(typeUtil.isArray({})).to.equal(false) }) });

运行测试

在当前目录下运行./node_modules/.bin/karma start或者添加如下代码到package.json "scripts": { "test": "karma start" }

​ 然后运行npm run test

查看结果

命令行能看到运行结果在工程目录下的coverage目录能看到相应的覆盖率报告

存在的问题

Karma是将测试Case在浏览器中运行并查看结果，当页面的url 改变的时候，会影响到整个Karma的执行，会有类似Some of your tests did a full page reload!这样的提示。上面打开百度首页检查按钮和title的例子在Karma中还没有找到合适的方式写出来。

参考资料

Automated testing with Headless Chrome使用HeadlessChrome做单页应用SEO基于HeadlessChrome的网页自动化测试系统-FinalTest使用 headless chrome进行测试使用 headless chrome进行测试UI自动化测试之Headless browser容器化初探 Headless ChromeKarma原理及论文karma入门karma 测试框架的前世今生