Testing React

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In order to encourage people to support my work, I’ve decided to publish a TL;DR version of this chapter for the community. This will allow me to develop more content, so it’s a win-win really.

You can access the full chapter by buying a copy through Leanpub↗. It goes into detail, whereas the following should give you a rough idea of the chapter contents.

TL;DR

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• Basic testing techniques include unit testing, acceptance testing, property based testing, and mutation testing.
• Unit testing allows us to ascertain specific certain truths.
• Acceptance testing allows us to test qualitative aspects of our system.
• Property based testing (see QuickCheck↗) is more generic and allows us to cover a wider range of values more easily. These tests are more difficult to write, though.
• Mutation testing makes it possible to test the tests. Unfortunately, it’s not a particularly popular technique with JavaScript yet.
• Cesar Andreu’s web-app↗ has a nice testing setup (Mocha/Karma/Istanbul).
• Code coverage helps us to understand what parts of the code remain untested. It does not, however, give us any guarantees of the quality of our tests.
• React Test Utilities↗ give us a nice way to write unit tests for components. There are lighter APIs, such as jquense/react-testutil-query↗.
• Alt provides a good means for testing actions↗ and stores↗.
• Testing provides you confidence. This will become particularly important as your codebase grows. It will become harder to break things inadvertently.

Buy the book↗ for more detail.