Mochitests

We use mochitests to do functional (and possibly integration) testing. Mochitests are part of Firefox and allow us to test activity stream literally as you would use it.

Mochitests live in test/browser, and as of this writing, they are all the browser-chrome flavor of mochitests. They currently only run against the bootstrapped version of the add-on in system-addon, not the test pilot version at the top level directory.

Adding New Tests

If you add new tests, make sure to list them in the browser.ini file. You will see the other tests there. Add a new entry with the same format as the others. You can also add new JS or HTML files by listing in under support-files. Make sure to start your test name with “browser_”, so that the test suite knows the pick it up. E.g: “browser_as_my_new_test.js”.

Writing Tests

Here are a few tips for writing mochitests:

  • Only write mochitests for testing the interaction of multiple components on the page and to make sure that the protocol is working.

  • If you need to access the content page, use ContentTask.spawn:

ContentTask.spawn(gBrowser.selectedBrowser, null, function* () {
  content.wrappedJSObject.foo();
});

The above calls the function foo that exists in the page itself. You can also access the DOM this way: content.document.querySelector, if you want to click a button or do other things. You can even you use assertions inside this callback to check DOM state.