Selenium/Ruby/Browser testing

Rationale
Why automate tests at the browser level? They find bugs!

Browser tests are most useful for:
 * Beta features: checking that they work in all browsers.
 * JavaScript: different browsers interpret JS in different ways.
 * Features requiring navigation: unit tests don't navigate.
 * Fragile: if something breaks often, we want to test it regularly.
 * Critical: features that must work all the time.

It's tedious to test manually Wikimedia sites within the multiple browser/operating system combinations that are out there, so we do automated testing to find errors and assure quality.

We use Cucumber because it lets you write tests in plain English; you don't need to know Ruby. Cucumber implements an idea called Acceptance Test Driven Development. The plain English test specifications open a communication channel with non-technical people who wish to contribute to browser test automation.

Check some real examples.

How to contribute
Here's one way to dive in

This doesn't require any local code at all, it's all on the web.
 * Analyze failing tests in Jenkins browser test runs.
 * Investigate a recent test that's failing
 * drop in to and ask if it's a known issue
 * Look at the test's Build Artifacts, it may have .png files that are screenshots of failed tests.
 * Watch the screencast of the failing test and/or view the test's code.
 * If you manually go through the test's steps on a wiki site (see Quality Assurance/Feature testing) and the test failure reveals a problem, then file a bug against the feature under test.

The next level is to fix broken tests and write new ones.
 * Follow the browser testing setup instructions
 * Run browser tests yourself, pointing to some MediaWiki install
 * If the test fails for you but the feature under test seems to be working, try fixing the test, and rerun it.
 * If you find an error in a test, file a bug...
 * and better yet contribute a fix for it in gerrit.
 * You can improve browser tests and write new ones. We use a high-level language that makes tests more approachable.
 * Check the list of EASY tasks – especially good for new contributors.

None of these steps require you to have a working local MediaWiki installation, though you may find it easier to deploy a MediaWiki-Vagrant virtual machine "appliance" which automates installing some of the tools you need and checks out the MediaWiki source code. This also gives you a local working MediaWiki instance, so you can go a level deeper and modify the code of the feature under test to fix it yourself.

If you are interested in automated browser tests, join the proposed MediaWiki Group Browser testing.

Resources

 * Current test results.
 * Browser test source code in Gerrit, mirrored at GitHub.
 * We use given-when-then testing format.