Vite ignores base: ''

[DreierF]

• Read the docs.
• Use Vite >=2.0. (1.x is no longer supported)
• If the issue is related to 1.x -> 2.0 upgrade, read the Migration Guide first.

Describe the bug

Setting base to an empty string is ignored by vite and it uses / instead. We need this as our app is deployed at varying base URLs that are unknown at build time.
I'm not entirely sure whether this works as intended or not as the docs don't explicitly mention this case. But it at least used to work up to 2.0.0-beta.37, but was probably broken by 809d4bd, while @vitejs/plugin-legacy still produces the expected path without / prefix.

Reproduction

Simply set base to '' in the config.

System Info

• vite version: 2.0.0-beta.44
• Operating System: MacOS
• Node version: 14.15.4
• Package manager (npm/yarn/pnpm) and version: yarn

[cawa-93]

This also leads to build issues for the electron application, where the path to the files must be relative rather than absolute.

In the current version, no matter how hard you try, you can't get relative file paths:

// config.js
  base: './',

// index.html
<script type="module" crossorigin src="/./index.2cf5b0d7.js"></script>
<link rel="stylesheet" href="/./index.3855d19f.css">

Must be ./index.2cf5b0d7.js or index.2cf5b0d7.js

[yyx990803]

Wouldn't a relative/empty base mess up asset references in CSS?

- dist
  - assets
    - foo.css -> url(./assets/foo.png)
    - foo.png

[DreierF]

We have relativeUrls set to true in the less options.