Yarn v2 Support

[br0p0p]

Hi, I forked this to add Yarn v2 support.

I think the best solution would be to merge that here and either create a new branch with Yarn v2 support or determine the Yarn version in the code and call either yarn cache dir or yarn config get cacheFolder whether Yarn v1 or v2 is detected, respectively.

What are your thoughts?

[thisismydesign]

Thanks!

Linking the fork for reference: https://github.com/br0p0p/gha-yarn-cache

What does Yarn v2 respond to yarn cache dir? Maybe if this part returns empty then we could try the v2 syntax?

[br0p0p]

Running yarn cache dir with Yarn v2 errors:

Unknown Syntax Error: Command not found; did you mean:

$ yarn cache clean [--mirror] [--all]
While running cache dir

However running yarn config get cacheFolder with v1 results in

undefined

[br0p0p]

so, the v2 command (yarn config get cacheFolder) could be the default and the v1 command (yarn cache dir) could be the fallback if the first result is undefined

[thisismydesign]

Yes! If you're up for submitting a PR I'd be happy to release a v2 with this functionality.

[thisismydesign]

@br0p0p v2 released: https://github.com/c-hive/gha-yarn-cache/releases/tag/v2 Let me know if it works for you.

Thanks for your help!