Jest: Add a way to only run certain jest runners in watch mode

[DanielMSchmidt]

🚀 Feature Proposal

I would like to be able to select certain jest runners to run in watch mode while being in watch mode.

Motivation

I have projects where I want to configure ~5 different runners. Having them all run in watch mode makes it hard to read the output of debug statements I do in jest unit tests for example.

Example

I would like to be able to run all runners & tests, see that one test is failing, select the runner it's failing on, add debug statements to the test, fix the test, go back to all runners being started without needing to stop and restart jest.

Pitch

It needs to go to the core because runners are a part of core and so is the nice watch mode screen I would like to extend.

[DanielMSchmidt]

Just as a note on this: I would be willing to do a PR, but I would need some information before I start:

1) What would be good shortcuts to use for selecting a runner / going back to all runners?
2) Should we select the runners by checkboxes or should it be a search like with the test names?
3) Is it currently possible to start the watch mode for only a limited set of runners? If so, we should disable this feature right?

[rickhanlonii]

I think you'll be able to configure this on your own when we land custom watch mode plugins in Jest 23 👌

[SimenB]

Having a way to say which project you want to run would be awesome. A custom watch mode to set it would be fine, but we need the filtering first

[DanielMSchmidt]

@rickhanlonii That sounds like an awesome feature. Would you think is it not of enough value for the "normal" user, so we shouldn't add it to core?

[rogeliog]

@DanielMSchmidt I published https://github.com/rogeliog/jest-watch-select-projects.

From what I understand, it should solve this issue. I'll close it, but feel free to reopen it if I'm wrong 🙃

[SimenB]

Awesome! 🎉

I think we should include a project filter in Jest core. I'm fine with the watch plugin living outside, but we should have some way of saying jest --runWithProject lint or something.

Then you can use that same configuration in the plugin 🙂

[DanielMSchmidt]

Sounds great 👍 I would be willing to do this to learn a bit more about jest's internals if that's okay for you :)

[SimenB]

Yes, please go for it!

[SimenB]

Can track the remaining work in #7542