Increase React components unit-test coverage with jest

[manojVivek]

[sidthesloth92]

@manojVivek Can we create a checklist of all the items we want to be covered so that different people can contribute small chunks? Something like this one: https://github.com/firefox-devtools/devtools-core/issues/415

[manojVivek]

@sidthesloth92 That is a good idea. But not sure if the checklist is the right way here, as testing each component is going to be a big chunk of work on its own. But either way, I'll try to put together a list of components and add to this.

[sidthesloth92]

Definitely we can have separate issues. Since you have the in depth knowledge of the app you can create a complete list and then we can have a to-do list linking to individual issues and we can just check them out here.

[durgakiran]

@manojVivek @jjavierdguezas I think the first step here should be a stable and working setup of testing frameworks to actually write test cases. The reason why I am putting this out is, the existing test setup is not working (the issue is probably related jest config combined with Flow js). This failing setup is actually discouraging us to start writing test cases, at least the enhancements that contributors are doing.

One more thing I want to suggest is instead of using enzyme, we should move to react testing library. I react testing library is a much better and stable, user perspective testing framework.