chore: add all missing peer dependency statements

[quantizor]

This allows for better deduping in client projects.

Might fix #4226

[brunocabral88]

I don't think this change will do what you think it will do they way it stands:

• Listing packages as a peerDependency means styled-components expect the consuming application to have downloaded those dependencies beforehand, which I believe is not the case here (I might be wrong though 😄)

To achieve what you want (better dedupe on the consuming apps side) you can simply change the dependencies listed in the dependencies array to use the range syntax like you used here. NPM/Yarn will be smart and reuse the dependencies versions already present on the consuming side if there's a match for that range..

[quantizor]

That's why they're defined in both peer and regular dependencies, with peerDependenciesMeta declaring all but "react" are optional

[brunocabral88]

But since the dependencies array still defines fixed versions, it'll overwrite the peerDependenciesMeta, won't it? 🤔

[quantizor]

I tested it linked against the styled-components-website repo and it seems to work as expected (at least using yarn.) A test version is published as styled-components@6.1.5-rc.0 if you want to give it a shot.

[quantizor]

Tested the explicit dependency + permissive peer dep with a bunch of different pms:

Worked (installed only the higher version): yarn, pnpm
Didn't work (installed both versions): npm, bun

The tricky thing is with react the range is really wide (16.8 and up basically.) I could move things out of peerDependencies into devDependencies, but basically no pm automatically installs peerDependencies out of the box so users would get hit with an error to add the dependency explicitly. The goal of this was to ensure the relevant libraries are available at least at the version we specify, with peerDependencies meant to deduplicate to a greater applicable version if defined in the client repository.

[quantizor]

I opened an issue against npm, I think yarn and pnpm behavior is correct.

[brunocabral88]

Hmm, interesting one.. I expected PMs to make dependencies take precedence over peerDependencies as, to me, peerDependencies was purely informational to let consuming apps know that you expect something to be there.. However, that doesn't seem to be the behavior the accepted RFC you linked describes..

Even if they fix npm, it'll take time for people to adopt the version with the fix..
IMHO, if I consume a library that has a dependency: "A": "^1.1.0", I would think that library was integration-tested with that package with that version, although anything in the range might work..

The goal of this was to ensure the relevant libraries are available at least at the version we specify

You just precisely described (in my understanding) the dependencies array when used with ranges :D

[brunocabral88]

I imported styled-components@6.1.5-rc.0 into the styled-components-website and ran yarn.. it did not take into account the peerDependencies array (that specifies postcss: ^8.4.31 - should've resolved postcss to 8.4.32)..

When I removed the peerDependencies and set the dependencies to be a range (postcss: ^8.4.0 for testing purposes), it resolved postcss to 8.4.32

[quantizor]

It's more obvious in the repo I linked in the bug ticket since that repo has postcss saved already at a higher version

[kachkaev]

I'm afraid that this change is breaking. Example: kachkaev/njt#549

If something is a peer dependency, not a dependency, builds would fail if the dependency is not mentioned in downstream package.json. So if we want to make something a peer dependency, I guess that a new version needs to be semver-major. A migration guide should list dependencies that need to be added to the app’s package.json.

[quantizor]

I added optional status (via peerDependenciesMeta, an official package.json field in the npm docs) to all of them except react itself, is the build tooling not taking that into account?

[quantizor]

It's odd because I tested it in pnpm and resolution worked as expected... will roll the change back.

[kachkaev]

Thanks for reverting! App build in kachkaev/njt#549 worked after upgrading styled-components from from 6.1.7 to 6.1.8 👍