How to Run & Write Tests

Running Tests


Run all tests:

npm test

Run single test:

npm test -- static/js/redux/__tests__/schema.test.js


Run all tests:

python test

Run all tests for a single app:

python test timetable

Run single test suite:

python test timetable.tests.UrlsTest

Run single test case:

python test timetable.tests.UrlTest.test_urls_call_correct_views

Run tests without resetting db:

python test -k

Our current test runner will only run db setup if the tests you’re running touch the db.

Writing Tests

Unit Tests

Contributors are encouraged to write unit tests for changed or new code. By separating out logic into simple pure functions, you can isolate the behaviour you care about in your unit tests, and not worry about testing for side effects. Following the design principles outlined in the resources from the Learning The Stack section helps with this. For example, extracting all code that extract information from the state into selectors, which are pure functions that take the state (or some part of it) as input and output some data, will make it easy to test and change any state related behavior. Sometimes you may want to test behaviour that can’t be extracted into a pure function, or that touches external interfaces. There are a number of strategies you can use in these cases.

Integration Tests

In the frontend, for testing the logic for rendering a component, look into snapshot tests. For testing async (thunk) action creators, our current tests create a store with desired initial state, dispatch the action, and then check that the action had the desired effect on the state. Backend requests are mocked using the nock library.

For testing views, we use django’s built in client to send requests to the backend. It’s also possible to use django’s request factory to create requests to provide directly as input to your views.

End to End Tests

As the name implies, end to end tests test the entire app at once by simulating a semesterly user. When writing or changing end to end tests, it is recommended to familiarize yourself with the methods provided in SeleniumTestCase, which make it easy to perform certain actions on the app.