If addWatchFile() is called by a Vite plugin after the server is closed, the watcher will be set, preventing Node.js process from exiting.

For example, if vite:css was in the middle of transforming a file when the server is closed, vite:css may call addWatchFile() , which will hang the process.

1. Clone this repository

   git clone https://github.com/maxpatiiuk/vite-watcher-hangs

2. Install dependencies

   cd vite-watcher-hangs
   cd vite-app
   npm install

3. Run the Vite server

   npx vite

4. See that the Node.js process does not exit after the server is closed

   • Comment out line 27 in vite.config.ts and see that the server exists correctly as this way the watcher is set before the server is closed.

Multiple built-in Vite plugins are setting watchers for files. For example, vite:css plugin:

https://github.com/vitejs/vite/blob/0474550c9fe0b252536b8d1f5190b3aca8723b71/packages/vite/src/node/plugins/css.ts#L384

These watchers are set even if server.watcher.close() was called.

These watchers in turn prevent the Node.js process from exiting, hanging it.

Solutions:

• In server.close(), if there are pending requests, after the requests are processed, close all watchers again if any were open.
• OR Make PluginContext.addWatchFile() a noop after the watcher is closed
• OR Add a check for watcher being closed before calling addWatchFile (error prone)

I am starting Vite dev server inside Vitest global setup file. (Vite dev server is used for Puppeteer)

The Vite dev server is closed in the global teardown file.

If some test fails, the teardown is called early, while Vite dev server might still be in the process of transforming a CSS file.

The vite:css plugin may set a file watcher, prevent Vitest from exiting. Vitest prints this message:

close timed out after 10000ms
Tests closed successfully but something prevents Vite server from exiting
You can try to identify the cause by enabling "hanging-process" reporter. See https://vitest.dev/config/#reporters

The hanging-process reporter points to file system watchers set by vite:css plugin.