Asset extension matching not consistent between DEV and PREVIEW

[Laavenx]

Describe the bug

Preview build of sveltekit doesn't match asset paths the same way as dev build.

Reproduction

Put let's say image.PNG inside of static then in index.svelte <img src="/image.png" /> and let's run npm run dev, then run build and preview and the image won't be displayed anymore.

Logs

No response

System Info

System:
    OS: Windows 10 10.0.19041
    CPU: (6) x64 Intel(R) Core(TM) i5-8600K CPU @ 3.60GHz
    Memory: 6.21 GB / 15.94 GB
  Binaries:
    Node: 16.15.0 - C:\Program Files\nodejs\node.EXE
    npm: 8.8.0 - C:\Program Files\nodejs\npm.CMD
  Browsers:
    Edge: Spartan (44.19041.1023.0), Chromium (97.0.1072.76)
  npmPackages:
    @sveltejs/adapter-auto: next => 1.0.0-next.40
    @sveltejs/kit: next => 1.0.0-next.328
    svelte: ^3.44.0 => 3.48.0

Severity

annoyance

Additional Information

No response

[Conduitry]

I can't reproduce this. It's working fine for me. Please provide a complete clonable repo that reproduces the issue.

[Laavenx]

All you have to do is rename svelte-welcome.png and webp to svelte-welcome.PNG and WEBP in demo template (build should also throw 404 error). If that doesn't work then its interesting why it works this way on my system.

[Conduitry]

This sounds like a case sensitivity thing. I see you're on Windows and you're requesting the file with a lower case extension and it looks like the file is named with an upper case extension.

[Rich-Harris]

We should probably enforce correct case at dev time

[Conduitry]

Do we have the access/control necessary for that? Isn't Vite solely responsible for serving those assets, and we just give it the directory to use?

[Rich-Harris]

No, we use sirv so that we have more control:

kit/packages/kit/src/core/dev/plugin.js

Lines 200 to 204 in ae416be

	if (fs.existsSync(file) && !fs.statSync(file).isDirectory()) {
	req.url = encodeURI(pathname); // don't need query/hash
	asset_server(req, res);
	return;
	}

kit/packages/kit/src/core/dev/plugin.js

Lines 176 to 181 in ae416be

	const asset_server = sirv(config.kit.files.assets, {
	dev: true,
	etag: true,
	maxAge: 0,
	extensions: []
	});

I don't recall if sirv can enforce the correct case, but we could do it easily enough before handing off to sirv.