Vite Multipage URL Bug

Multipage apps created with Vite have inconsistent URL behavior between the dev server and the build.

Description

Using the following folder structure:

├── package.json
├── vite.config.js
├── index.html
└── nested
    └── index.html

Expected

Both dev and build use the same URL to access the nested page; either:

1. <root>/nested
2. <root>/nested/
3. both of the above

Actual

• Dev: nested page cannot be accessed without the trailing slash (<root>/nested/)
• Build: nested page can be accessed with or without trailing slash

Steps to reproduce

1. Clone this repository.
2. Run npm install at the repository root.
3. Run npm run dev and attempt to navigate to localhost:3000/nested. You should see "Main Page". Navigating to localhost:3000/nested/ produces the desired "Nested Page".
4. Run npm run build and npm run preview, then navigate to localhost:5000/nested. You should see "Nested Page". The same occurs when adding the trailing slash.