Support yarn berry

[christophehurpeau]

Hello,

It seems yarn 2 still needs this. I started working on a version that only supports yarn berry: https://github.com/christophehurpeau/yarn-deduplicate/tree/wip-berry

My findings are:

• use of @yarnpkg/parsers instead of @yarnpkg/lockfile. It also means that the packages are not split automaticly like it was the case in @yarnpkg/lockfile, so merging has to be handled manually
• there is a new information before the version (I called it source, but not sure if it's the right name). In my lockfiles, it's almost awlays npm, except for different versions of resolve, like resolve@^1.10.0 and other patched versions of resolve, like resolve@patch:resolve@^1.10.0#builtin<compat/resolve>

Do you plan to work on a berry version ?

[Bnaya]

yarn berry is under very active development,
I believe it will be possible to bake that into it

[SimenB]

@scinos @rjatkins any thoughts on this? For v2/berry it could be designed as a plugin rather than a separate tool, so we could run yarn deduplicate instead of yarn-deduplicate. I.e. the approach of (the unmaintained?) https://github.com/eps1lon/yarn-plugin-deduplicate

[scinos]

It makes a lot of sense to use the new plugin framework.

I'll try to look into writing a plugin (or reviving https://github.com/eps1lon/yarn-plugin-deduplicate) soon, first I need to understand how the plugin system works and get my hands on a few yarn v2 repos with duplicated packages to test everything.

If anyone wants to start working on it meanwhile, it would be great :)

[scinos]

There is also this yarnpkg/berry#1558

[SimenB]

^ just landed, so I guess this can be closed?

[JounQin]

yarnplugins/yarn-plugin-deduplicate#13

I hope we can reconsider this.

I'll raise a PR for it like ds300/patch-package#507.

[christophehurpeau]

@JounQin note that I have working fork here https://github.com/christophehurpeau/yarn-deduplicate / https://www.npmjs.com/package/yarn-berry-deduplicate
I hope to convert it to a yarn plugin some day if this is still not implemented in yarn

[JounQin]

@christophehurpeau Thanks for your information, but I'd like to raise a PR for yarn-deduplicate itself to support yarn v1 and v2+ at the same time~

[scinos]

Yarn V2+ supports yarn dedupe natively. What's the goal of adding support for V2 to this tool?

[JounQin]

Yarn V2+ supports yarn dedupe natively. What's the goal of adding support for V2 to this tool?

It doesn't support --strategy fewer, yet.

See also yarnpkg/berry#2297

[scinos]

Looks like nobody is opposed to add the fewer strategy to Yarn.

I haven't looked at the yarn dedupe code in ages, but, from memory, it was really similar to yarn-deduplicate. Meaning that implementing the strategy should be relatively easy.

I may have some time this week to have a look.

[JounQin]

I may have some time this week to have a look.

Do you mean you want to work this this week? That would be great! I and my colleague were going to working on this feature also but on yarn-deduplicate's side.

The benefit is, we can use prepare: yarn-duplicate script to run yarn-duplicate every time on installation. But prepare: yarn dedupe will run into a dead loop, at least for now.

(For prepare script support for yarn berry, see also https://github.com/un-es/yarn-plugin-prepare-lifecycle)

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Besides, can we reopen this issue first?