What's the verdict on mjs support?

[craigmulligan]

Is this a bug report?

No, It's a question on the release conventions of the project. I was wondering how fixes for the current release are ported to the next branch?

I was depending on this bug fix https://github.com/facebook/create-react-app/pull/4085/files, from 1.1.2 but then needed some updated dependencies, so started using react-scripts@next but found that that fix is not present.

I'd expect all of master/current release to be merged into next is that not the case? or is it a manual process?

Thanks in advance! 👍

[gaearon]

I believe it was cherry picked to next but we haven’t cut a new next version yet. Plan to in a few days.

[craigmulligan]

Okay, thanks for the clarification @gaearon will wait for the next next release 👌

[craigmulligan]

Oh it looks like it hasn't been cherry-picked into next yet. I've opened a PR doing that #4318.

[Timer]

This was intentionally not cherry-picked because it's a sub-optimal bugfix.
Per comment on the PR's thread, I think @gaearon was in favor of removing mjs support all together (in 2.0) until we can support it properly (this is my position, anyway).

[craigmulligan]

@Timer oh thanks for pointing that out, read the full thread now and agree it's suboptimal. Shall I close the PR and keep the issue open so we can track the mjs plan?

[Timer]

You can leave the PR open; if we don't figure out proper support we'll probably roll with it.

Would you like to help with ensuring proper support? The Jest feature request would be a great start.

[iansu]

What exactly do we need for proper support? Is it just Jest and webpack handling .mjs files appropriately? If that's in place do we need to do anything more on our side?

[Timer]

Jest and then we need to make sure that webpack resolves starting with js or mjs properly from main when module is missing (which means we need to merge the PR removing the extension from our paths.appIndexJs or whatever).

[chadfurman]

3 months later -- where are with with this?

[chadfurman]

I see in the latest webpack.config.dev.js for react-scripts that we have .mjs before .js in the extensions list

[Timer]

We're dropping mjs support in 2.0 until Jest supports it, please follow jestjs/jest#4842.