Add support for sparse-checkout

[dfdez]

Context:

Monorepo sometimes can be challenging mainly when having a huge base of code. A lot of people have encounter situation where they don't need to fetch everything inside the repository, with this new option anyone will be able to make sparse-checkout inside github action quite simple!

Features:

• Added sparse-checkout option
• Added test for sparse-checkout
• Updated README.md with sparse-checkout option and examples

Usage:

Fetch only the root files

- uses: actions/checkout@v3
  with:
    sparse-checkout: .

Fetch only the root files and .github and src folder

- uses: actions/checkout@v3
  with:
    sparse-checkout: |
      .github
      src

Once the first sparse-checkout is made you can download more folders with the command git sparse-checkout add SOME/DIR/ECTORY more details rewarding sparse-checkout here

Implementation

In order to make sparase-checkout much useful I have added to the git fetch the possibility to add a filter in order to use --filter='blob:none'.

With this update we will make sure that when the fetch is done no blob of the repository will be downloaded (this filter will be done only when sparse-checkout is set), instead the blobs will be downloaded when making the git checkout after having the sparse-checkout configured.

Here you can find the article that I have used to guide me to make the implementation.

Related Issues

• Support Sparse checkouts actions/checkout#800
• Add support for sparse checkouts actions/checkout#680

[dfdez]

Merged here!