ERR_INVALID_FILE_URL_PATH happens when resolving alias including @ with importer

[sapphi-red]

When resolving alias including @ with importer, ERR_INVALID_FILE_URL_PATH happens.
The implementation of importer is below.

const importer = (p, importer) => {
  return { file: path.resolve(__dirname, './src', p.replace(/^\/@\//, '')) }
}

Also I am using legacy render function.

This works well with dart-sass.

Error message

Error: Error: TypeError [ERR_INVALID_FILE_URL_PATH]: File URL path must be absolute
  ╷
1 │ @import '/@/bar.scss';
  │         ^^^^^^^^^^^^^
  ╵
  src\foo.scss 1:9  root stylesheet
    at handleCompileResponse (D:\documents\GitHub\sass-embedded-atmark-invalid-url-reproduction\node_modules\sass-embedded\dist\lib\src\compile.js:213:15)
    at compileRequestAsync (D:\documents\GitHub\sass-embedded-atmark-invalid-url-reproduction\node_modules\sass-embedded\dist\lib\src\compile.js:101:16)
    at processTicksAndRejections (node:internal/process/task_queues:96:5)

Step to reproduce

1. Clone https://github.com/sapphi-red/sass-embedded-atmark-invalid-url-reproduction.
2. Run npm i.
3. Run node sass.js
4. dart-sass runs with no error. sass-embedded fails with error.

Additional context

I was trying to use sass-embedded with vite (vitejs/vite#6734).
I used npm i -D sass@npm:sass-embedded@latest to install/replace it.
Then I tried but this error occured. So I created a minimal reproduction without vite.

[nex3]

I can't reproduce this:

$ git clone https://github.com/sapphi-red/sass-embedded-atmark-invalid-url-reproduction
Cloning into 'sass-embedded-atmark-invalid-url-reproduction'...
remote: Enumerating objects: 12, done.
remote: Counting objects: 100% (12/12), done.
remote: Compressing objects: 100% (8/8), done.
remote: Total 12 (delta 0), reused 12 (delta 0), pack-reused 0
Receiving objects: 100% (12/12), 9.10 KiB | 4.55 MiB/s, done.

$ cd sass-embedded-atmark-invalid-url-reproduction/
$ npm i

added 69 packages, and audited 70 packages in 2s

8 packages are looking for funding
  run `npm fund` for details

found 0 vulnerabilities

$ node sass.js
[dart-sass]
.bar {
  color: blue;
}

.foo {
  color: red;
}

-----------
[sass-embedded]
.bar {
  color: blue;
}

.foo {
  color: red;
}

[sapphi-red]

Thanks for taking a look.

Look like this only happens on windows.
When I ran this script on windows, it happened. But it did not happen when I ran this script on WSL.

[nex3]

Okay, I can reproduce this now. Here's what's going on under the covers:

• The Sass compiler encounters @import "/@/bar.scss".
• Because the embedded host implements legacy-API importers as a wrapper around the modern API, the compiler attempts to resolve this import relative to the current URL.
• Since any URL beginning with / is a root-relative URL, the relative resolution here is file:///@/bar.scss.
• The embedded host then tries to convert this resolved URL to a path, which fails on Windows because @ isn't a valid drive name.

Note that the @ sign isn't actually the problem here; this will also reproduce with any root-relative URL that isn't a valid Windows path, such as /whatever/bar.scss. The solution is probably to catch path-conversion errors and treat them as though the path couldn't be found, effectively passing on the original string to the importer in question.

[sapphi-red]

Thank you for the fix!
I confirmed that #129 will fix for me.