[lexical-markdown] Add test to keep code language

[Minhir]

[lexical-markdown] Bug Fix: preserve language tag for Markdown code

Right now, PR contains only one commit with tests to highlight the problem.

If the markdown file contains a code block with an unsupported language (a language for which the project doesn't have syntax highlighter) the lexical will remove any information about that language.

Let's say we have markdown with the following content:

```rust
fn main() {
    println!("Hello World!");
}
```

If we don't have prism-rust in the project, lexical will strip all the info about the language and saved file will look like:

```
fn main() {
    println!("Hello World!");
}
```

That behavior seems to me like a bug.

Possible solution

I think CodeNode should always keep __language field, no matter what the mapToPrismLanguage() returns. And we can create another field called __isSyntaxHighlightSupported for highlighting check.

What do you think? I'll be happy to create another commit with a fix if provided solution works for the lexical team.

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The latest updates on your projects. Learn more about Vercel for Git ↗︎

Name	Status	Preview	Comments	Updated (UTC)
lexical	✅ Ready (Inspect)	Visit Preview	💬 Add feedback	Jun 9, 2024 4:59pm
lexical-playground	✅ Ready (Inspect)	Visit Preview	💬 Add feedback	Jun 9, 2024 4:59pm

[github-actions]

size-limit report 📦

Path	Size
lexical - cjs	28.31 KB (0%)
lexical - esm	28.13 KB (0%)
@lexical/rich-text - cjs	36.77 KB (0%)
@lexical/rich-text - esm	28.09 KB (0%)
@lexical/plain-text - cjs	35.36 KB (0%)
@lexical/plain-text - esm	25.33 KB (0%)
@lexical/react - cjs	38.51 KB (0%)
@lexical/react - esm	29.14 KB (0%)

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[StyleT]

Makes sense! Commit with the fix would really help here :P

[mayneyao]

try {
    return language ? window.Prism.languages.hasOwnProperty(language) : false;
} catch (error) {
    return false
}

this may help the headless editor work in a Web Worker

[Minhir]

Good point!