TypeError: Cannot read property '18' of undefined

[chenxsan]

Initial checklist

• I read the support docs
• I read the contributing guide
• I agree to follow the code of conduct
• I searched issues and couldn’t find anything (or linked relevant results below)

Affected packages and versions

remark-gfm 2.0.0

Link to runnable example

No response

Steps to reproduce

1. clone code from Use ESM webpack/webpack.js.org#5396
2. run yarn
3. run yarn start

Expected behavior

No error.

Actual behavior

Errors like Cannot read property '29' of undefined show up many times. For example, https://github.com/webpack/webpack.js.org/pull/5396/checks?check_run_id=3495415399#step:5:3025.

FYI we don't use react-markdown, so it might not be related to #22. And the error is not helpful at all, so I don't know how to track it down the problem.

Runtime

Node v12

Package manager

yarn v1

OS

Linux

Build and bundle tools

Webpack

[ChristianMurphy]

Cannot read property '18' of undefined

the error is not helpful at all, so I don't know how to track it down the problem.

It sounds like an error coming from micromark.
Micromark has a production build and a debug build (which produces nicer errors) https://github.com/micromark/micromark#api
You can access the debug build by adding --conditions development to the node call which runs remark/micromark.

[wooorm]

Probably a mismatch between versions: either upgrade the other tools, or downgrade remark-gfm!

[chenxsan]

There's no error with the lower version remark-gfm. My plan in that pull request is to migrate all remark plugins to the ESM versions, so downgrading would be my last resort.

Anyway I've tried replacing @mdx-js/loader@2.0.0-next.9 with xdm, that errors were gone. So it might be the cause.

[wooorm]

Closing this as it’s more of an external issue. mdx-js should soon be up to do btw!

[RomanHotsiy]

I'm using the latest next.9 version of mdx-js with remark-gfm@3.0.0 and still getting this error.

@wooorm is it expected?

Maybe it's worth to keep either this issue open or open an issue in mdx-js repo so this won't get missed for the 2.0 release of mdx-js?

Also, do you know the root cause of the issue or do you need help to find it out? I'd be happy to help 🙌

[wooorm]

Hey! It's expected. You can use v1 with the latest mdx I believe.
It is already solved on main in mdx-js, and a new RC is likely to go out on Tuesday or so.

If you want to help, you can do so by proofreading the site for the much improved RC and V2: v2.mdxjs.com. Note though that the corresponding RC has not yet been released!