`bundleStrategy: inline` generating files that are not used

[wighawag]

Describe the bug

As mentioned in #2042 (comment)

bundleStrategy: "inline" still generate an _app folder with js file imported at runtime, instead of being inlined

It also generate a env.js and version.json file

See reproduction repo : https://github.com/wighawag/svelte-kit-single-file

Reproduction

Reproduction repo: https://github.com/wighawag/svelte-kit-single-file

It is based on pnpx sv create so test it with:

pnpm i
pnpm build

Logs

System Info

System:
    OS: Linux 6.8 Linux Mint 22 (Wilma)
    CPU: (16) x64 AMD Ryzen 7 PRO 6850U with Radeon Graphics
    Memory: 14.83 GB / 30.12 GB
    Container: Yes
    Shell: 3.7.0 - /usr/bin/fish
  Binaries:
    Node: 22.14.0 - ~/.volta/tools/image/node/22.14.0/bin/node
    npm: 10.9.2 - ~/.volta/tools/image/node/22.14.0/bin/npm
    pnpm: 10.6.5 - ~/.volta/bin/pnpm
    bun: 1.2.0 - ~/.asdf/shims/bun
  Browsers:
    Brave Browser: 131.1.73.105
    Chromium: 131.0.6778.204
  npmPackages:
    @sveltejs/adapter-static: ^3.0.8 => 3.0.8 
    @sveltejs/kit: ^2.16.0 => 2.20.5 
    @sveltejs/vite-plugin-svelte: ^5.0.0 => 5.0.3 
    svelte: ^5.0.0 => 5.25.12 
    vite: ^6.2.5 => 6.2.6

Severity

blocking all usage of SvelteKit

Additional Information

No response

[khromov]

If you expect to be able to double-click to run your project (ie without using a web server), you need to enable the hash router, then SvelteKit will not fetch env.js or or version.json.

You can find an example of a correctly configured project that you can run by double-clicking the output index.html file here:
https://github.com/khromov/derivault/

[wighawag]

My use case is actually different, I just want one file.

I can confirm though that with the following I can double-click the index.html and see it does not try to load any other file

router: {
	type: 'hash'
},

Now, regarding the extra file generated, I see that they do not seem to be loaded, even the one in the _app folder.

So what is their purpose, would they be loaded in some condition ?

My use case, as mentioned require to have a single index.html file that contains everything and so I expect svelte-kit to be able to not generate the extra files if they are actually not needed

[khromov]

I've also observed that JS files are being generated even when you set bundleStrategy: inline but these JS files are not actually loaded, so you don't need them and can delete them. Of course there's lots of quirks here such as if you put files in static/ folder or import images using something like import image from '$lib/image.png' then Kit probably can't package those into your single HTML file. But for a simple case such as the repo I linked without external resources, it works.

[wighawag]

Thanks @khromov I updated the issue title to reflect the issue at hand: that it generate files not needed

[mench32]

I also noticed that the issue happens with any bundleStrategy setting.

SvelteKit generates unused CSS files, for example in the assets folder there are CSS files starting with _.

[datacutter]

I’m also experiencing this issue. SvelteKit generates unused CSS files.

[teemingc]

Unused files:

• env.js
• _app/immutable/bundle.js
• _app/immutable/assets/style.css