Support ESM config (.eslintrc.mjs)

[jsejcksn]

Search terms used: is:issue is:open mjs OR esm OR "es module"

cf. #12593, which was auto-closed. All of the issues/RFCs mentioned as blockers in that issue are now closed/merged.

What is the status of ES module support for config files? In the form of

• .eslintrc.mjs or
• .eslintrc.js where the nearest package.json includes "type": "module"

[kaicataldo]

Now that we have an asynchronous API, I believe that supporting .mjs is unblocked from a technical standpoint. For the second bullet point, ESLint does already support .eslintrc.cjs files, so this should not be an issue (see here for more details).

[kaicataldo]

Would you like to create an RFC for adding support for .mjs?

[jsejcksn]

@kaicataldo Oh, wow—I thought this was already on the roadmap based on all of the discussion around it. I’ll take a look at the RFC process. Does it require having any knowledge of ESLint’s internal API (not user API)?

[kaicataldo]

The RFC template is a section for outlining what kind of changes would be required to implement it, which is really useful both for evaluating trade offs as well as for whoever ends up implementing the accepted RFC.

This is definitely something we want to do, but I do think it makes sense to go through this process to make sure we approach it thoughtfully.

[jsejcksn]

@kaicataldo I looked and I don't think I have enough knowledge about ESLint internals to provide implementation details. Is there an RFC for an RFC 😄?

[kaicataldo]

Ha! My personal take is that this is something we’re going to have to implement eventually anyway, if you’re willing to wait :)

In the meantime, it should be possible to use a .eslintrc.cjs configuration file.

[jsejcksn]

Sure—I just didn't see a place to track ESM configs specifically, so I created this issue.

[Rishabh-malhotraa]

@kaicataldo I would like to try to solve this issue :)

[kaicataldo]

@Rishabh-malhotraa Great! As mentioned above, the next step is create an RFC for this so that we can decide how this should be implemented.

[nzakas]

Given that we are moving forward with a different config system, I think any changes should be proposed for the new system rather than continuing to modify the current system.
eslint/rfcs#9