Updated documentation to make contributing a tiny bit easier

[adrienthiery]

Summary:

I had a little bit of a hard time testing my changes, because I didn't have the reflex to look for the CONTRIBUTING.md file.
Also, not sure why, but the method described to test your changes directly does not seem to work for me, nothing happens, so I added the way to test it using yarn link

Test Plan:

This is documentation only :)

[thymikee]

Thank you for your efforts, this is much appreciated! If running the CLI directly doesn't work (I remember using it for init, which doesn't interoperate with platform-related packages), maybe we should remove it, or only show it for init?

[thymikee]

You can see this gets pretty complicated and only affects a single package. We need an npm-script that would cd to every package and run yarn link there, so that folks can then run:

yarn link @react-native-community/cli-tools @react-native-community/cli-platform-ios  @react-native-community/cli-platform-android @react-native-community/cli @react-native-community/cli-types

Then we could write something like:

Using yarn link

CLI is a monorepo with multiple packages interacting with each-other. In order to effortlessly test your changes you'll need to "link" them using yarn link for every package. You can do so with this command:

yarn link-packages

And then, in your test project, run:

yarn link @react-native-community/cli-tools @react-native-community/cli-platform-ios  @react-native-community/cli-platform-android @react-native-community/cli @react-native-community/cli-types

From now on, your test project will transparently use the CLI from symlinked packages.

[grabbou]

Yeah, I remember running into it when I did link/cli and ended up not seeing my Android changes.

[adrienthiery]

Ok, I'll work on that !

[grabbou]

I would get rid of this setup entirely. I think it's potentially confusing. When you run the CLI directly from a different folder, you're still going to be loading "platform-android" and "platform-ios" packages from the "node_modules" of your project.

This is because CLI itself doesn't load Android/iOS specific commands anymore. It finds React Native dependency and that's the package that depends on cli-platform-android and cli-platform-ios.

So in order to see your changes in these two, you'd have to link them anyway.

[grabbou]

(writing as I've run into this issue myself right now haha)

[thymikee]

Yes please. I think it only makes sense for detached commands like init

[adrienthiery]

Sounds good, I'll remove this part then :)

[adrienthiery]

Updated the PR!

[thymikee]

I don't see this necessary. yarn link only marks a dependency as "linkable", no need to unlink these. Also, please remove global-cli here and in link-packages, we don't want anybody to touch it for now.

[adrienthiery]

Could be useful in a very few cases where you have several clone of the cli on your machine? 😅 Ok, very small chance.
Do you still want me to remove it? 🙂

[thymikee]

Almost there :)