Add support for pnpm and Yarn PnP

[Kocal]

For Yarn PnP and pnpm support, Encore needs to configure peerDependenciesMeta as explained in #655.

I've configured every packages listed in lib/features.js as optional peerDependencies, and webpack as a required peer dependency.

I'm not sure of how we can write tests for that, any idea @weaverryan? Maybe an E2E test with a real app/dedicated CI workflow? EDIT: implemented E2E tests for Yarn PnP and pnpm.

Thanks!

[Kocal]

Fixing tests for windows is making me crazy 🤯

[arderyp]

Thanks for doing all of this @Kocal, looks like you're almost there!

[stof]

Note that due to the new required peer dependency, this requires releasing it as a new major version.

[weaverryan]

Note that due to the new required peer dependency, this requires releasing it as a new major version

I was thinking the same, which is ok. To be clear, the new peer dependency is webpack itself.

So I'm still wondering about webpack-cli. This is NOT currently listed as a peerDependency. However, in all of the "test apps", it IS installed. Why isn't this a required peer dependency?

[stof]

It is an optional peer dependency of webpack, that must be installed to be able to use webpack in the CLI (rather than using it programmatically). And so, in Encore, we need it.

I suggest adding webpack-cli as a mandatory peer dependency of Encore, instead of having the first usage of Encore failing and asking the user to install webpack-cli.

[Kocal]

Re-added webpack-cli as a required peer dependency.

[weaverryan]

Thank you Hugo for taking this on! Can you open a recipe PR - we will need to include webpack and webpack-cli in package.json and bump to v4 of Encore. I'm not going to tag quite yet, because I haven't played with this yet and I'd like to get comfortable and do some local testing first.

[Kocal]

Thanks Ryan :) I'm gonna open a recipe PR ASAP.

EDIT: opened at https://github.com/symfony/recipes/pull/1123