[Bug]: HMR does not update a shared local dependency

[clemvnt]

Describe the bug

Hello,

I have an issue where HMR does not work for a shared file: dependency.

I have a minimal reproduction with two Vite apps using @module-federation/vite:

• apps/host-app
• apps/remote-app

Both apps depend on two local dependencies via file: dependencies:

• pkgs/shared-pkg
• pkgs/not-shared-pkg

The difference is that shared-pkg is declared in the Module Federation shared config in both apps, while not-shared-pkg is not.

In dev mode, HMR behaves differently depending on which local dependency changes:

• Changing pkgs/not-shared-pkg/index.js works as expected and the UI updates through HMR.
• Changing pkgs/shared-pkg/index.js does not update the UI through HMR.

This makes it look like HMR is broken specifically for local dependencies that are shared through Module Federation.

Reproduction

1. Clone https://github.com/clemvnt/vite-mf-shared-package-hmr-issue.
2. Install dependencies in both apps.
3. Start apps/remote-app with npm run dev.
4. Start apps/host-app with npm run dev.
5. Open both apps in the browser.
6. Edit pkgs/not-shared-pkg/index.js and change the exported value from "A" to "B".
7. Observe that both apps update correctly.
8. Edit pkgs/shared-pkg/index.js and change the exported value from "A" to "B".
9. Observe that the apps do not update correctly through HMR.

Actual behavior

Changes in the non-shared local dependency are reflected immediately, but changes in the shared local dependency are not.

Expected behavior

When a shared local dependency changes, both apps should receive the update in dev mode, the same way they do for a local dependency that is not shared.

Note

I suspect the issue may be related to shared dependencies being included in optimizeDeps.

Validations

• Read the docs.
• Read the common issues list.
• Check that there isn't already an issue that reports the same bug to avoid creating a duplicate.
• The provided reproduction is a minimal reproducible example of the bug.

[gioboa]

Thanks for the report, I'll look into that. if you want you can try to drop a PR too 🙏

[gioboa]

Thanks for the repo precious example. 🙏
I checked the code, unfortunately MFE requires Vite to pre-bundle shared local dependencies, caching them and permanently disabling native HMR.
You can use and configure vite-plugin-restart to automatically restart the server when shared packages change.

plugins: [
  ViteRestart({ restart: ['../../pkgs/shared-pkg/**/*'] }),  <--- This
  federation({
    [...]
  }),
]

--- UPDATE ---

I'm working on adding a configuration property to hide "the restart logic" inside the plugin.