Tree-shaking support for module federation

[XiaofengXie16]

Is there going to be a plan for adding tree shaking support for module federation?

Use case:
Several of my apps are sharing 10-15 ui components from a large UI library (tree-shakable) . However, when I try to use module federation to share this library, I would have to share the entire UI library instead of the components that the apps use which means I have to download unused code from the library.

[alexander-akait]

Because we don't know which components you will use, how you imagine it?

[literalpie]

It would be nice if there was a way to define all expected possible imports, and maybe webpack could use that to tree-shake? Maybe this could just be a js file with a list of import statements.

It would be even cooler if, when code references something not in the "expected imports", it could fall back to the un-treeshaken version of the dependency.

It would absolutely awesome if there was a way in dev mode to "trace" all imports that happen as you run the app and automatically generate the "all needed imports definition" mentioned in step 1.

(I'm just spit-balling here - sorry if none of this is feasible)

[literalpie]

I played around with this some and found some things that might be useful. I made a commit in this fork of the examples repo with my notes and example code.

The gist is that, in my experimenting, you can "trick" webpack into treeshaking in certain ways by having a shared dependency that re-exports the specific things that you want included.

I'm always impressed whenever I say "it would be cool if webpack could..." and it actually does it!

[rodoabad]

You can still tree shake your library upon consumption for your remotes. To which I guess, it's going to start to depend whether it's better to add that package to shared versus letting Webpack tree shake that package upon consumption of your remotes.

@alexander-akait would you agree on that approach instead?

[alexander-akait]

@rodoabad Yeah, I think it already works as you written