Add better support for partially staged files

[sedubois]

See react-boilerplate/react-boilerplate#1064 (comment) for description

[okonet]

Partial staging bugging me a lot but I don't know how to solve this. If you know how to solve that issue, you're welcome to re-open the issue and file a PR. Otherwise I'll close the issue as won't fix.

[sedubois]

Sure 😊 I'm not familiar with the mechanism, so I don't have a solution to propose right now.

[sedubois]

Why not simply temporarily doing git stash -k?

[okonet]

Can you elaborate on ↑ since I'm not familiar with how it works.

This sounds interesting and is worth trying. Thanks for pointing it out.

[okonet]

@sedubois I'm a bit stuck with #75. Do you have ideas how to solve it probably?

[sedubois]

Hmm. Maybe first concentrate on the simple case when linter doesn't modify the working copy, and address the case of eslint --fix separately?

Also you proposed in PR to git stash pop after the commit, but conflicts would also happen in that case, no? Sounds like the conflict is unavoidable and the user should then be given the opportunity to resolve it?

[okonet]

Also you proposed in PR to git stash pop after the commit, but conflicts would also happen in that case, no?

I don't think it will. The conflict will only happen if the actual content has diverged from stashed one. Otherwise, it will successfully merge them. So this use case can be solved with the post-command.

address the case of eslint --fix separately

I really don't want to loose this feature. So if there is a way of not losing it, I'd take this effort. So for now this is the only issue that prevents me from releasing it (besides of some code that needs to be written and the cleanup).

[okonet]

For now, the second case doesn't seem to be solvable without a user interaction which sucks :(

If someone has a better solution for that, any ideas are appreciated!

See #73 for some more context.

[sedubois]

Well, if you stash then allow linters to perform changes, conflicts might happen. Either don't stash, or disable the linter --fix option. Maybe you can let the user choose what they prefer.

Personally I would just disable the --fix option, so that I can use stash -k. Otherwise, lint-staged's behavior is simply incorrect (it lints code which isn't meant to be committed).

[okonet]

These aren't solutions but workaround of the problem :(

To add git stash you don't need to change anything in the library itself. You can just add those to the config:

{
  "*.js": ["git stash -k", "eslint", "git stash pop"]
}