Fix using Vite env var names in Markdown (#3412)

[hippotastic]

Changes

• Fix bug 🐛 BUG: Cannot reference import.meta.env in a Markdown file #3412 in vite-plugin-markdown by converting the first dot in every occurrence of import.meta.env. to its Unicode escape sequence, which prevents Vite from replacing strings like import.meta.env.SITE in our JS representation of loaded Markdown files
• Add tests.

Testing

I added a new test case and ran all tests successfully.

Docs

Not a visible change, just a bugfix.

[changeset-bot]

🦋 Changeset detected

Latest commit: 2312492

The changes in this PR will be included in the next version bump.

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[aFuzzyBear]

Fantastic 🦛 !!!
This looks amazing, thanks again for the effort on putting this together and really tackling the issue at the root.
💚💚💚

[aFuzzyBear]

😎 Looking Dam Good 🦛

[bholmesdev]

Nice change that should make our docs wayyyy simpler! Just curious though, are you still able to use import.meta.* with explicit JSX expressions? Ex. If I wanted to insert import.meta.env.SITE, could I use {import.meta.env.SITE}? (my hunch is yes it works but just confirming)

[hippotastic]

What do you mean with "still able to use", @bholmesdev? This didn't work in Markdown before my changes, and it still doesn't! 😅 I can have a look and try to fix that, too. I agree it would be nice to actually be able to use those in Markdown, too.

[ghost]

@hippotastic oh SHOOT I assumed it did work at some point! Well dang that’s a bummer. Still happy to approve this change 👍

[bholmesdev]

Very important change 👏

[hippotastic]

@hippotastic oh SHOOT I assumed it did work at some point! Well dang that’s a bummer. Still happy to approve this change 👍

Haha yeah, I also assumed that it works and was surprised to see that it didn't when I created this PR. 😅 The {import.meta.env.SITE} JSX syntax was invalid before my changes and it unfortunately still is. I've just had a look and think it will take longer to make this syntax work.

I'd therefore suggest to wrap this PR up first and separate making the JSX syntax work into a new PR.