Support Sparse checkouts

[devminded]

Discussed in https://github.com/actions/checkout/discussions/798

^{Originally posted by devminded May 20, 2022}

Support sparse checkouts

Purpose

When using large project with many modules (AKA monorepo) being able to do sparse checkouts (supported since git 2.25.x) would be very helpful.

Example

Repo containing:

• scripts
• tools
• modules/mobile-client
• modules/server
• modules/web

We want to only checkout and build the mobile-client (nice when combined with paths/paths_ignore).
So the equivalent of git sparse-checkout init --cone && git sparse-checkout set modules/mobile-client scripts tools would be:

- name: Checkout tools repo
  uses: actions/checkout@v3
  with:
    repository: my-org/my-repo
    sparse:
      - modules/mobile-client
      - scripts
      - tools

Ref: https://github.blog/2020-01-17-bring-your-monorepo-down-to-size-with-sparse-checkout/

[devminded]

Related #172 #680

[mversluys]

Worth noting that this https://github.com/actions/checkout/blob/main/src/git-source-provider.ts#L188 causes all LFS files to be retrieved for the given branch.

When using sparse-checkout AND lfs, checkout will only download lfs files as needed so the sparse rules can be used to prevent a lot of stuff being downloaded which is great, but only with the call to git lfs fetch origin ... being removed.

[KIC]

any news on this? I this feature planned to be implemented?

[dfdez]

Hey everyone! Good news for those that need this feature, I have created a PR to add sparse-checkout support! 🎉

[dfdez]

This Issue has been solved! #1369

[tamird]

This can probably be closed? @TingluoHuang

[devminded]

Thank you very much team.