addWatchFile can not be used to watch files outside of the module graph

[zauni]

Describe the bug

When I am writing a plugin and using "addWatchFile" inside the plugin to watch files which are not imported in some JS file, then Vite is tracking that the file has changed, but doesn't reload because of the message "no modules matched"

For example I added some-other-file.yaml with "addWatchFile" and then Vite in debug mode logs this on changes:

vite:hmr [file change] some-other-file.yaml +42m
vite:hmr [no modules matched] some-other-file.yaml +1ms

In the reproduction you have to do npm run dev and then change the file some-other-file.yaml to see this output.

If I do this in rollup, it is doing the reload on file changes. But Vite is somewhere loosing the info of the file path inside the module graph.

This was noticed when developing the rollup-plugin-openapi

Reproduction

https://stackblitz.com/edit/vitejs-vite-wuaaxt?file=vite.config.js

System Info

System:
    OS: macOS 12.2.1
    CPU: (10) arm64 Apple M1 Pro
    Memory: 68.09 MB / 32.00 GB
    Shell: 5.8 - /bin/zsh
  Binaries:
    Node: 16.14.0 - ~/Library/Caches/fnm_multishells/14259_1645436772510/bin/node
    npm: 8.3.1 - ~/Library/Caches/fnm_multishells/14259_1645436772510/bin/npm
  Browsers:
    Chrome: 98.0.4758.102
    Firefox: 97.0
    Firefox Developer Edition: 98.0
    Safari: 15.3
npmPackages:
    vite: ^2.7.2 => 2.8.4 

Used Package Manager

npm

Logs

vite:hmr [file change] some-other-file.yaml +42m
vite:hmr [no modules matched] some-other-file.yaml +1ms

Validations

• Follow our Code of Conduct
• Read the Contributing Guidelines.
• Read the docs.
• Check that there isn't already an issue that reports the same bug to avoid creating a duplicate.
• Make sure this is a Vite issue and not a framework-specific issue. For example, if it's a Vue SFC related bug, it should likely be reported to https://github.com/vuejs/core instead.
• Check that this is a concrete bug. For Q&A open a GitHub Discussion or join our Discord Chat Server.
• The provided reproduction is a minimal reproducible example of the bug.

[jplhomer]

I assume the expectation here is to force a full page reload, yeah?

[zauni]

@jplhomer Yes that would be the expectation. I don't think that HMR is possible in this case or even makes sense because the user wants to add arbitrary files to the watcher with the addWatchFile method. Or that is how I understand the use case of this method.

[zauni]

@jplhomer I was able to workaround the issue by adding a hook for handleHotUpdate and invalidating the root YAML file when a referenced YAML file was changed. And then I can send a full-reload command to the WebSocket server and everything works as expected.

@see zauni/rollup-plugin-openapi@4a2b480

Should I leave the issue open to address the underlying problem with addWatchFile or should I close it because a workaround exists?

[jplhomer]

Seems like the underlying problem should still be addressed 👍