🐛 BUG: regression in handling of string literal props

[delucis]

What version of @astrojs/compiler-rs are you using?

0.3.1

What package manager are you using?

pnpm

What operating system are you using?

macOS

Describe the Bug

With @astrojs/compiler is was possible to use escaped characters like \n in a string prop and have that show up when used:

<MyComponent prop="Example\nwith\nnew\nlines" />

---
// MyComponent.astro
---
<p>{Astro.props.prop}</p>

Would render as:

<p>Example
with
new
lines</p>

With @astrojs/compiler-rs the same usage treats the \ as a literal backslash and renders:

<p>Example\nwith\nnew\nlines</p>

Probably unusual usage but we were depending on this in the astro.new repo here: https://github.com/withastro/astro.new/blob/d15d68e5562e524eed798039cb1cceacb43f6e7a/src/components/ResourceCard.astro#L41 (Using white-space: pre-line; in the CSS there means the \n were respected and displayed, but when updating to Astro 7 and the new compiler I spotted this regression.)

Notably, the compiler does handle these cases as expected:

<Component prop={"One,\ntwo,\nthree."} />

<Component prop={`One,\ntwo,\nthree.`} />

<Component prop={`One,
two,
three.`} />

Link to Minimal Reproducible Example

https://stackblitz.com/edit/github-mndctqis?file=src%2FComponent.astro,src%2Fpages%2Findex.astro

[matthewp]

Here's what each compile to:

• parent: https://play.astro.build/#code=LQAtAC0ACgAKAC0ALQAtAAoACgA8AE0AeQBDAG8AbQBwAG8AbgBlAG4AdAAgAHAAcgBvAHAAPQAiAEUAeABhAG0AcABsAGUAXABuAHcAaQB0AGgAXABuAG4AZQB3AFwAbgBsAGkAbgBlAHMAIgAgAC8APgA%3D&sourcemap=external&compact=none&scopedStyleStrategy=where&filename=index.astro
• child: https://play.astro.build/#code=LQAtAC0ACgBjAG8AbgBzAHQAIABwAHIAbwBwACAAPQAgACIARQB4AGEAbQBwAGwAZQBcAG4AdwBpAHQAaABcAG4AbgBlAHcAXABuAGwAaQBuAGUAcwAiADsACgAtAC0ALQAKADwAcAA%2BAHsAcAByAG8AcAB9ADwALwBwAD4A&sourcemap=external&compact=none&scopedStyleStrategy=where&filename=index.astro

Both look fine to me.

[delucis]

Ah great — I remembered Erika had this new playground but couldn’t find a link, thanks for that.

In that case I guess it’s in Astro’s render logic? Something to do with the new whitespace handling? Or some security-related hardening that’s now escaping \n in strings? Should we move the issue to the main monorepo?

[matthewp]

I'm not sure yet, do you know what version this was working the way you expected? We've always escaped text content so it is not likely that.

[delucis]

I spotted it in this PR: withastro/astro.new#108

So working in 6.4.8, broken in 7.0.7.