Font Awesome 6 SVG comments cause errors with plugin

[adrianosmond]

An extra ! has been added in the comments in the SVGs in Font Awesome 6, so they change from
<!-- Font Awesome Pro 5... to <!--! Font Awesome Pro 6...

I believe this additional ! is causing issues for this plugin.

Steps to reproduce

• Edit the comment in test/fixtures/commented.svg in this repository, adding an extra ! between the <!-- and the F which is currently the first non-whitespace character. It doesn't seem to matter if you add more whitespace before the extra !, as long as the ! is the first non-whitespace character.
• Run the tests on the repository

Expected behavior

• The tests should pass

Actual behavior

• They fail

[ljharb]

Unfortunately the commented fixture doesn't run in tests right now, because babel can't parse it, so I'm not sure how we'd verify the fix.

[adrianosmond]

I'm almost definitely misunderstanding something, but isn't it being run on line 208 of test/sanity.js?

I cloned the repo and ran npm run test with both the existing and the FA6 style comment in that fixture and got one result that looked like a success and one that looked like a failure to me.

[ljharb]

ohh right, sorry, it's only svgo: false that's commented out. i'll look into it.

[ljharb]

This seems like it's a babel parse error, so it's something babel would have to fix. Could you file it there?

[adrianosmond]

I think you're wrong there. Babel is erroring, but that's because Babel is being asked to parse an XML comment as JSX and it isn't valid JSX.

I did a little investigation and the issue is coming from the fact that SVGO deliberately doesn't remove these comments by default as they're apparently a convention used for copyright/licensing. svg/svgo#1811

[ljharb]

hm, ok. in that case i'm not sure what the solution is, since this plugin uses babel to parse SVGs.