[HOLD] fix(worker): Avoid webpack error on "node:" modules in workflows

[mjameswh]

What changed

• In the workflow bundler, ignored modules get replaced by an empty object from Webpack's externals hook, in addition to aliases.

Why

• If workflow code add an import on some node: prefixed module, Webpack would fail to build, because that namespace is not supported for our target.
• Fixes How to add module to disallowedModules? #1036

[bergundy]

Should we change to return an empty object? Is this better experience in your opinion?

[mjameswh]

Not sure what you mean... Do you mean var false vs var {}?

[bergundy]

We used to return undefined here.

[mjameswh]

Oh, I see... Actually, THIS is the fix.

By returning var {}, we are telling Webpack to replace imports of that module by an empty object. This is essentially the same as what we do with alias, but externals is called much earlier in the process, so that we can still handle invalid namespaces such as node:.

[mjameswh]

Putting this one on hold.

After some more consideration, I think that the currently proposed solution will make it significantly more difficult for users to load build-time polyfills.

For this reason, it might be preferable that we simply rewire node:* to * from externals, then let alias behave as before, thus making it possible for users to load polyfill by overwriting the corresponding entry in alias.

[CLAassistant]

All committers have signed the CLA.