WebdriverIO lets you use your favorite testing framework (Jasmine, Mocha, Cucumber) and assertion library (Chai for Mocha). Other projects implement their own testing and assertion APIs, for example [Nightwatch](http://nightwatchjs.org/api), [Intern](https://theintern.github.io/intern/#writing-functional-test). It should be mentioned though that v4.2.16 has an incompatibility with at least [tap](http://www.node-tap.org/) v7.1.2: stdout/stderr written during a run gets lost.
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Pro Allows screenshots (either the full page or parts of it) if performing UI testing
There are times where you don't want to open up a browser for screencaps, that is where CasperJS comes to use, it can render the page using its own rendering engine and take and save a screenshot for you, all via the commandline
Pro Easy to understand
Since all webdevs know JS, the start-up time of learning the framework will be reduced to zero, as your team can be productive from day one.
Pro Easily integrates with other applications
Due to the simplicity of the framework, not only other libraries can be built with it, but it can be integrated with any web application as well.
Pro Works with any testing framework or assertion library
WebdriverIO lets you use your favorite testing framework (Jasmine, Mocha, Cucumber) and assertion library (Chai for Mocha). Other projects implement their own testing and assertion APIs, for example Nightwatch, Intern.
It should be mentioned though that v4.2.16 has an incompatibility with at least tap v7.1.2: stdout/stderr written during a run gets lost.
Pro Used by Chimp.js
Chimp.js, is an emerging web application test framework that implements easy sync tests using WebdriverIO, CucumberJS and Chai. Features include:
- synchronous style
- built-in "widget framework" (an implementation of the PageObject pattern)
- automatically downloads dependencies (ChromeDriver, PhantomJS etc.)
- works with SauceLabs and BrowserStack (CrossBrowserTesting TBD)
- automatically takes screenshots on failures
- works on Windows in addition to Linux and OS X
- automatically produces boilerplate code for step definitions, which you can copy, paste and edit
- file watcher reuses the browser sessions and can run only the tests you tag, to maximize development speed
Pro Excellent API documentation
Pro Synchronous implementation of asynchronous browser commands
So you don't need to worry about promises
Pro Config file generation wizard
wdio config and WebdriverIO will generate a config file for testing locally vs. in the cloud, specifying the test framework (Jasmine, Cucumber, Mocha), where to find tests and store screenshots etc.
Pro Allows you to do visual regression tests using WebdriverCSS
WebdriverIO has a plugin called WebdriverCSS that allows you to do cross visual platfrom/browser tests with an integration to Applitools.
Pro Provides plugins for gulp, grunt and other
WebdriverIO is accessible via gulp and grunt and even has a Sublime Text plugin for autocompletion.
Pro Simpler syntax than selenium-webdriverjs and WD.js
driver.get('http://www.google.com'); driver.findElement(webdriver.By.id('q')).sendKeys('webdriver'); driver.findElement(webdriver.By.id('btnG')).click();
browser .get("http://www.google.com") .elementById('q') .sendKeys('webdriver') .elementById('btnG') .click()
client .url('http://google.com') .setValue('#q','webdriver') .click('#btnG')
Pro Used by Meteor's Velocity test runner
If you develop web applications with Meteor.js, you might want to use the xlovio:webdriver wrapper, because it's the Selenium binding behind the preferred testing framework (Chimp) promoted by the Velocity (Meteor's official testing framework) team for using BDD via Cucumber.
Pro Selenium Server need not be started independently
Service is provided by WebdriverIO which over comes the con of starting selenium server independently.
Con Not for unit testing but rather UI testing
These are two extremely different concepts. CasperJS should be removed from this list
Con Cannot guarantee 100% accurate Webkit-based browser screenshots
QtWebKit is the rendering engine used by CasperJS. Keep in mind this is NOT the same rendering engine as Chrome; hence, if you want to be 100% sure of the results, you must run a Webkit browser (such as Chrome) yourself.
Con Must run with WDIO to debug
Tasks written in this beautiful Selenium API can only be debugged using the provided WDIO task runner. You can't set breakpoints within tasks, but you can have WDIO pause the run between Selenium commands.
Con Selenium server must be started independently
selenium-webdriverjs starts the Selenium server automatically, and actually manages to achieve a faster startup time (4 seconds vs. 5.5) than WebdriverIO.