When I use vite as host to realize "shared-directory" case of "https://github.com/module-federation/module-federation-examples" can not run after build

[ghost]

Repreduction

https://github.com/kehuay/shared-directory

1. pnpm --filter=shared-directory-* build
2. pnpm --filter=shared-directory-* preview

Results

• rust host

• vite host

[gioboa]

Hi @kehuay thanks for you feedback. We need to investigate.

[frolovsky]

@kehuay
Thank you for reporting this issue! After reviewing your case, I’ve been able to identify the cause of the problem. Here’s an explanation:

1. This is not a bug with @module-federation/vite.

The issue arises from how Vite handles module resolution in different modes (development vs. build/preview). In development mode (vite), Vite uses an internal module resolution mechanism that automatically resolves paths like shared/file2 relative to the source directory (src). This is why your imports work as expected during development.

However, during the build or preview phase (vite build or vite preview), Vite relies on Rollup for module bundling. Rollup does not support implicit path resolution like Vite. As a result, imports such as shared/file2 will not be resolved unless explicitly configured.

In short, the issue is related to unresolved paths in the build process, not a bug in the @module-federation/vite plugin. But, ideally, the build should also fail, just like when trying to build without the plugin(?) @gioboa

---

2. How to fix this

You can resolve this issue in two ways:

1. Update your imports to use relative paths. For example:

// Instead of this:
import file1Default from "shared/dir1/file1";
import { A } from "shared/file2";

// Use this:
import file1Default from "./shared/dir1/file1";
import { A } from "./shared/file2";

2. Configure an alias in vite.config.js
   If you want to keep the existing absolute-like paths (e.g., shared/file2), you can define an alias for shared in your vite.config.js file:

export default defineConfig({
  resolve: {
    alias: {
      shared: '/src/shared', // Adjust this path based on your project structure
    },
  },
});

[frolovsky]

https://github.com/kehuay/shared-directory/pull/1 - example