All about testing

Kitsune has a fairly comprehensive Python test suite. Changes should not break tests—only change a test if there is a good reason to change the expected behavior—and new code should come with tests.

Running the Test Suite

If you followed the steps in the installation docs, then you should be all set setup-wise.

To run the tests, you need to do:

./manage.py test

That doesn’t provide the most sensible defaults for running the tests. Here is a good command to alias to something short:

./manage.py test -s --noinput --logging-clear-handlers

The -s flag is important if you want to be able to drop into PDB from within tests.

Some other helpful flags are:

-x:
Fast fail. Exit immediately on failure. No need to run the whole test suite if you already know something is broken.
--pdb:
Drop into PDB on an uncaught exception. (These show up as E or errors in the test results, not F or failures.)
--pdb-fail:
Drop into PDB on a test failure. This usually drops you right at the assertion.
--no-skip:
All SkipTests show up as errors. This is handy when things shouldn’t be skipping silently with reckless abandon.

Running a Subset of Tests

You can run part of the test suite by specifying the apps you want to run, like:

./manage.py test kitsune/wiki kitsune/search kitsune/kbforums

You can also specify modules:

./manage.py test kitsune.wiki.tests.test_views

You can specify specific tests:

./manage.py test kitsune.wiki.tests.test_views:VersionGroupTests.test_version_groups

See the output of ./manage.py test --help for more arguments.

Running tests without collecting static files

By default the test runner will run collectstatic to ensure that all the required assets have been collected to the static folder. If you do not want this default behavior you can run:

REUSE_STATIC=1 ./manage.py test

The Test Database

The test suite will create a new database named test_%s where %s is whatever value you have for settings.DATABASES['default']['NAME'].

Make sure the user has ALL on the test database as well. This is covered in the installation chapter.

When the schema changes, you may need to drop the test database. You can also run the test suite with FORCE_DB once to cause Django to drop and recreate it:

FORCE_DB=1 ./manage.py test -s --noinput --logging-clear-handlers

Writing New Tests

Code should be written so it can be tested, and then there should be tests for it.

When adding code to an app, tests should be added in that app that cover the new functionality. All apps have a tests module where tests should go. They will be discovered automatically by the test runner as long as the look like a test.

  • If you’re expecting reverse to return locales in the URL, use LocalizingClient instead of the default client for the TestCase class.
  • We use “modelmakers” instead of fixtures. Models should have modelmakers defined in the tests module of the Django app. For example, forums.tests.document is the modelmaker for forums.Models.Document class.

Changing Tests

Unless the current behavior, and thus the test that verifies that behavior is correct, is demonstrably wrong, don’t change tests. Tests may be refactored as long as its clear that the result is the same.

Removing Tests

On those rare, wonderful occasions when we get to remove code, we should remove the tests for it, as well.

If we liberate some functionality into a new package, the tests for that functionality should move to that package, too.

JavaScript Tests

Frontend JavaScript is currently tested with Mocha.

Running JavaScript Tests

To run tests, make sure you have have the NPM dependencies installed, and then run:

$ scripts/mocha.sh

Writing JavaScript Tests

Mocha tests are discovered using the pattern kitsune/*/static/*/js/tests/**/*.js. That means that any app can have a tests directory in its JavaScript directory, and the files in there will all be considered test files. Files that don’t define tests won’t cause issues, so it is safe to put testing utilities in these directories as well.

Here are a few tips for writing tests:

  • Any HTML required for your test should be added by the tests or a beforeEach function in that test suite. React is useful for this.
  • You can use sinon to mock out parts of libraries or functions under test. This is useful for testing AJAX.
  • The tests run in a Node.js environment. A browser environment can be simulated using jsdom. Specifically, mocha-jsdom is useful to set up and tear down the simulated environment.

Functional UI Tests

We can do more comprehensive front-end testing with the functional UI tests. They’re located in the tests/functional directory.

Installing dependencies

Follow the steps in the installation docs, including the test dependencies to make sure you have everything you need to run the tests. If you’re running the tests against a deployed environment then there’s no need to install anything other than Tox.

Create test users

Some of the tests require logging in as a administrator, and others require logging in as a user. To run these tests you will need to create accounts in the target environment. If you’re running against a local instance of the application you can create these users by running the following script:

$ ./manage.py shell < ./scripts/create_user_and_superuser.py

If you want to run the tests that require administrator access against a deployed instance, then you will need to ask someone on IRC to upgrade one of your test accounts.

The credentials associated with the test users are stored in a JSON file, which we then pass to the tests via the command line. If you used the above mentioned script, then these users are stored in /scripts/travis/variables.json. The variables file needs to be referenced on the command line when running the tests.

The following is an example JSON file with the values missing. You can use this as a template:

{
  "users": {
    "default": {
      "username": "",
      "password": "",
      "email": ""},
    "admin": {
      "username": "",
      "password": "",
      "email": ""}
  }
}

For the purposes of the examples below, assume you named your copy of the file my_variables.json.

Running the tests

Tests are run using the command line. Below are a couple of examples of running the tests:

To run all of the desktop tests against the default environment:

$ PYTEST_ADDOPTS=--variables=my_variables.json
$ tox -e desktop

To run against a different environment, pass in a value for --base-url, like so:

$ PYTEST_ADDOPTS=--base-url=https://support.allizom.org
$ PYTEST_ADDOPTS="${PYTEST_ADDOPTS} --variables=my_variables.json"
$ tox -e desktop

To run the mobile tests you will need to target a mobile device or emulator using a tool like Appium. You can create a suitable variables file with the necessary capabilities like so:

{
  "capabilities": {
    "platformName": "iOS",
    "platformVersion": "9.2",
    "deviceName": "iPhone 6",
    "browserName": "Safari",
  }
}

Then you can run this like so:

$ PYTEST_ADDOPTS=--driver=Remote
$ PYTEST_ADDOPTS="${PYTEST_ADDOPTS} --port=4723"
$ PYTEST_ADDOPTS="${PYTEST_ADDOPTS} --variables=capabilities.json"
$ PYTEST_ADDOPTS="${PYTEST_ADDOPTS} --variables=my_variables.json"
$ tox -e mobile

Alternatively, if you run the mobile tests in Firefox the user agent will be changed to masquerade as a mobile browser.

The pytest plugin that we use for running tests has a number of advanced command line options available. To see the options available, run pytest --help. The full documentation for the plugin can be found here.