bonniedotdev VS react-hooks-testing-library

Here’s an example of a custom hook with several related functions in my website code. Note that I don’t test this particular hook separately from the UI because it fits under this category in “When not to use the react-hooks library” : Your hook is easy to test by just testing the components using it.

While generally it's recommended to test the component using the hooks rather than the hooks themselves, sometimes you might find it necessary to test custom hooks directly. For such cases, there's React Hooks Testing Library. This library allows you to create a simple test harness for React hooks that handles running them within the body of a function component, as well as updating and unmounting them.

To do so, we can install and use Render hooks from React Testing Library:

Of course, you could isolate the logic inside a hook, and there's an awesome way of testing it with renderHook. But yet, you're trapped into react features, if they change their API, you will have to put your hands in your working logic and adapt some stuffs to keep up to date.

Relocating functions to a custom hook makes them accessible for testing (plus you’re keeping business logic separate from the UI, in accordance with best practices). There’s even a library to help with testing custom hooks: react-hooks-testing-library.

testing-library provides one more library exactly for such purpose allowing us to avoid headache and safe strength for actual testing. It is called @testing-library/react-hooks

Next, we need to install react-hooks-testing-library package. It's a simple testing utility that allows testing hooks with ease. You can read more about this package here.

As for hooks, there's https://react-hooks-testing-library.com/

Use @testing-library/reacthooks

Now I don't need to worry about React lifecycle methods. I can test my hook if I want to, but it hardly seems worth it here. If I would, it would be easier to do so using react-hooks-testing-library