Backslash sometimes inserted when using $ in text

[lourd]

I noticed that on some parts of my portfolio site (made with gatsby and gatsby-mdx), there are extra backslashes being inserted in some places where dollar signs are used. For example:

• Go to https://descioli.design/grove and Find for \$ — there are 6 occurrences on the page. There are 12 usages of $, though — not every $ is preceded by a backslash.
• The MDX source for that page is here. Note: no backslashes.
• The rendering of the page is here. Pretty standard AFAIK.

It only started happening when I switched from Remark to MDX. I didn't notice it when I did the initial switch.

Environment

• macOS and ubuntu, latest version
• @mdx-js/mdx@1.0.20, gatsby-mdx@0.6.3
• node@10.1.0, yarn@1.13.0

Steps to reproduce

Clone my portfolio repo, https://github.com/lourd/descioli-design, and run it. No additional configuration needed.

Expected behaviour

No extra backslashes.

Actual behaviour

Extra backslashes

[lourd]

This ended up being due to prettier. I'd set it up to run on pre-commit and missed the fact that it was also formatting .mdx files 🤦‍♂ Sorry to waste your time.

[johno]

I'm going to reopen since MDX output is in fact different than remark's. It's a bug in the template literal escaping that we'll need to address.

[lourd]

Just to be clear, it was Prettier that did the extra escape, not Remark. I switched to MDX and accidentally had Prettier format my .mdx file in the same commit, and incorrectly attributed the inserted backslash to the Remark-MDX switch.

…

On Fri, Jun 21, 2019, 9:54 AM John Otander ***@***.***> wrote: Reopened #606 <#606>. — You are receiving this because you modified the open/close state. Reply to this email directly, view it on GitHub <#606?email_source=notifications&email_token=AAPLJZBANLAMLUDBNNWOUM3P3TMRJA5CNFSM4HY33TUKYY3PNVWWK3TUL52HS4DFWZEXG43VMVCXMZLOORHG65DJMZUWGYLUNFXW5KTDN5WW2ZLOORPWSZGOSDORAVY#event-2430406743>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AAPLJZDEEMAYFCVHGWOWQXDP3TMRJANCNFSM4HY33TUA> .

[millette]

Should mdx handle $ and remove the \ when output, since $ must be escaped due to math support - see prettier/prettier#6213.

[johno]

Yeah, ultimately we should detect the presence of \$ and not escape it twice.

In the ideal world Prettier wouldn't add the $ escaping when there isn't inline math being used (or it at least wasn't the default), but it seems like we've reached the point where we need to solve it on our end.

[millette]

I even tried something like cost: 5{"$"} but that was output litteraly.