Change Request: Better support migrating JS config files

[nzakas]

Which packages would you like to change?

• @eslint/compat
• @eslint/config-array
• @eslint/migrate-config
• @eslint/object-schema

What problem do you want to solve?

Right now, migrate-config just takes the evaluated version of a .eslintrc.js file and converts that. While that works fine for mostly static .eslintrc.js files, it's not a good solution for complicated ones.

What do you think is the correct solution?

Ideally, we'd be able to do some code modifications via something like jscodeshift to update a .eslintrc.js file. This would likely be a different code path than for static config files.

Participation

• I am willing to submit a pull request for this change.

Additional comments

I don't have the bandwidth to take this on, so looking for a volunteer to investigate this.

[nzakas]

@fasttime are you still planning on working on this?

[fasttime]

@nzakas I'm sorry for the delay in sharing an update. I was thinking that, since we're discussing some changes to the configuration system, some of which will be experimental at first, it might make sense to postpone upgrading the migration tool until we have a clearer idea of the new features. What are your thoughts on this?

[nzakas]

I'm not sure that I'd consider the new features as blocking this work. We're already doing a good job with static config files, and applying to .js files is really the last piece. I'd imagine that one we have extends, we'd want to update this tool to use that anyway.

I do think other things you're working on (browser testing, concurrency) are higher priority than this, so no harm letting it sit a bit. I just don't think we should consider the config system changes to block this effort.