[unplugin] Why using require('webpack-sources') instead of require('webpack').sources?

[yoannmoinet]

Hello there 👋

I've seen a few issues slightly approaching the subject of webpack-sources and how it's declared in the published unplugin package.

From what I gathered, the need for it was introduced in unjs/unplugin#57.
But quickly after, webpack.sources was changed to a dependency on webpack-sources, but there is no information (I could find) on the subject.
It was committed directly on main on the same day, without much details.

It's proven difficult, from a consumer of unplugin's point of view, to fully understand what needs to be declared as a peerDependency, a dependency, or other.

Webpack do advise to use require('webpack').sources in their docs, in order not to break the compatibility chain between webpack and webpack-sources.

Tip

When consuming webpack-sources package in plugins, use require('webpack').sources instead of require('webpack-sources') to avoid version conflicts for persistent caching.

Right now, I'm afraid we do break this compatibility for older versions of webpack, currently, v4 uses webpack-sources@v1, by enforcing a version of webpack-sources onto webpack.

Mostly trying to understand the decision before applying changes (either via a PR, or directly in my code).

[yoannmoinet]

cc @antfu for visibility and maybe a chance to get more context on this.

[antfu]

It was a sync import, and I was trying not to include the whole webpack for every single unplugin. But as for now it's moved to lazy require, we could change to webpack then.

[antfu]

I see. I am up to moving to require('webpack').sources if anyone can help verify it works across webpack v5 and v4. In that case, I'd be happy to get a PR. Thanks

[yoannmoinet]

Awesome.
I'm willing to work on a PR and test it in both webpack 4 and 5 on my side.
Either tomorrow or later next week.

Thanks for the details!

[yoannmoinet]

Opened unjs/unplugin#431 to update this.