Describe the bug

transformIndexHtml() prints the following error when HTML contains a relative link to a script, and url parameter ends in slash (i.e. /example/dir/, and not /example/dir/index.html):

Pre-transform error: Failed to load url /example/filename.js (resolved id: /example/filename.js). Does the file exist?

This can occur when implementing the dev server following the SSR guide.

Cause

This happens because dirname() of the html url is taken which, for a path that ends in slash, removes the directory name. And the file is searched in the parent directory:

When using builtin vite server, it converts urls that end in slash to absolute filesystem paths that end in index.html:

but this doesn't happen for the SSR example since:

1. It uses appType: 'custom', which disables this url preprocessing
2. The custom handler uses req.originalUrl, which is not modified
3. The HTML file may not exist

Reproduction

https://stackblitz.com/edit/vitest-dev-vitest-bx1fvf91?file=index.js

Steps to reproduce

1. npm install
2. npm run dev
3. Observe the error message in console:

Pre-transform error: Failed to load url /example/filename.js (resolved id: /example/filename.js). Does the file exist?

4. Ctrl+C
5. Change /example/dir/ on line 4 to example/dir/index.html
6. npm run dev
7. Observe no error

System Info

System:
    OS: Linux 5.0 undefined
    CPU: (2) x64 Intel(R) Core(TM) i9-9880H CPU @ 2.30GHz
    Memory: 0 Bytes / 0 Bytes
    Shell: 1.0 - /bin/jsh
  Binaries:
    Node: 18.20.3 - /usr/local/bin/node
    Yarn: 1.22.19 - /usr/local/bin/yarn
    npm: 10.2.3 - /usr/local/bin/npm
    pnpm: 8.15.6 - /usr/local/bin/pnpm
  npmPackages:
    vite: latest => 5.4.11

Used Package Manager

npm

Logs

No response

Validations

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• The provided reproduction is a minimal reproducible example of the bug.