Feature request: Add a commonmark option

[a-ignatov-parc]

It seams that react-markdown staring from 3.0.0 isn't commonmark compliant any more because commonmark option is disabled by default in remark-parse. It's more breaking than public api changes and there is no notes about it. This was done on purpose?

[rexxars]

Yes. I got so many requests for tables and other non-commonmark features that I decided to switch. I could enable the commonmark option, but I'd have to make sure documentation clearly stated that certain features simply won't work in that mode.

[a-ignatov-parc]

I understand. And want to clarify that Commonmark spec allows adding any extensions we want (like tables). It's main goal is to make parsing more deterministic by strict syntax.

There is even list with proposed extensions.

Also github made there flavors upon commonmark spec. So I think it's a good idea to continue using commonmark ;)

[a-ignatov-parc]

At least we should have ability to pass commonmark option to remark-parse. I'd say it should be turned on by default but that would breaking change to v3 and backward compatible to v2 🤔

[rexxars]

I'd be open for adding the option. I don't want to enable it by default - I think that will lead to more support issues rather than less (though I appreciate a stricter format on a personal level).

[a-ignatov-parc]

Not going to argue 👍

But please mention in Readme that react-markdown@3 isn't commonmark compliant by default. This could be a big surprise for v2 users.

[a-ignatov-parc]

Also it would be good to point that remark-parse has some inconsistency with commonmark spec.

[rexxars]

This is now (kind of) possible by using the parserOptions feature in v4.1.0:

<ReactMarkdown source="# yer markdown" parserOptions={{commonmark: true}} />