{"id":1114,"date":"2014-10-11T22:00:08","date_gmt":"2014-10-11T19:00:08","guid":{"rendered":"http:\/\/www.webcodegeeks.com\/?p=1114"},"modified":"2014-10-11T17:55:36","modified_gmt":"2014-10-11T14:55:36","slug":"a-canonical-web-test-in-nodejs","status":"publish","type":"post","link":"https:\/\/www.webcodegeeks.com\/javascript\/node-js\/a-canonical-web-test-in-nodejs\/","title":{"rendered":"A canonical web test in NodeJS"},"content":{"rendered":"

Working with web applications in NodeJS is great. Using the same language and libraries on the client and server simplified the thinking. And NodeJS has fast tests and restart for a super quick edit-verify cycle when you\u2019re coding.<\/p>\n

I like to write tests to verify the server-side and client-side logic, but do you know that the whole solution really is working? You can of course test your service manually after deploying, but that becomes tedious. By using Selenium, we can test that the solution works end-to-end.<\/p>\n

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In this article, I show how to write a Mocha test that:<\/p>\n

    \n
  1. Starts up the Selenium test runner<\/li>\n
  2. Creates a browser client that can access the application (using PhantomJS)<\/li>\n
  3. Starts up the server and sends the browser to the server (running in ExpressJS)<\/li>\n
  4. Clicks a button in the web page that triggers some JavaScript (written in jQuery in this example)<\/li>\n
  5. Verifies that the call to the server returns and displays correct data<\/li>\n<\/ol>\n

    This test can be run with a simple command after you check out the code and requires no setup on the developers computer!<\/p>\n

    \r\ndescribe("web application", function() {\r\n  before(function(done) {\r\n    this.timeout(5000);\r\n    client = startWebDriver(function() {\r\n      startServer(function(url) {\r\n        client.init().url(url, done);\r\n      });\r\n    });\r\n  });\r\n\r\n  after(function(done) {\r\n    client.end(done);\r\n  })\r\n\r\n  it("clicks menu item", function(done) {\r\n    client.click("#showMore", function(err) {\r\n      client.waitFor("#results div", 1000, function(err) {\r\n        client.getText("#results div", function(err, text) {\r\n          expect(text).to.have.string("Here's more");\r\n          done();\r\n        });\r\n      });\r\n    });\r\n  });\r\n});\r\n<\/pre>\n
    This test starts a new server and client for each test. When using this for real, you really want to make sure you only start the server and the web driver once as these are expensive operations.<\/p>\n
    The test case of \u201cit clicks menu item\u201d has a lot of callbacks. There are versions of webdriver APIs for NodeJS which are based on promises that you may enjoy using more.<\/p>\n
    implementation details<\/h2>\n
    The full application can be found on Github<\/a>. To implement it, I used the following NPM modules:<\/p>\n