yarn.lock is untracked when setting up a local copy of the project

[lukyth]

Is your proposal related to a problem?

Yes.

When I try to contribute to this project by following the instruction in https://github.com/facebook/create-react-app/blob/master/CONTRIBUTING.md#setting-up-a-local-copy

1. Clone the repo with git clone https://github.com/facebook/create-react-app
2. Run yarn in the root create-react-app folder.

yarn.lock will be generated and is untracked.

Right now yarn.lock is neither checked in nor ignored by .gitignore. So I have to get rid of it somehow (stash/remove) when I commit the code. If I remove it and run yarn again, it'll just generate a new one. This could become a bit frustrating.

Describe the solution you'd like

Checking in yarn.lock as well. I could take care of this if the idea is accepted.

Describe alternatives you've considered

Ignore yarn.lock in .gitignore. But I'd rather avoid that and check it in instead according to https://yarnpkg.com/lang/en/docs/yarn-lock/#toc-check-into-source-control

Additional context

None.

[rovansteen]

Yeah I have always been wondering why it was not added to .gitignore. @iansu any reason for this?

[ianschmitz]

If we were to act on this I would suggest we ignore yarn.lock. By doing so we ensure that our CI installs the latest versions of packages to discover potential issues our users may encounter.

[rovansteen]

I remember that I had issues running the end-to-end tests because it runs a pristine check somewhere which fails because I had a yarn.lock file. So makes sense to add the file to gitignore then?

[lukyth]

Seems like it's a consensus that yarn.lock should be ignored. I'll open a PR for that then.