action.yaml

name: "Sparse Checkout"
description: "Sparse checkout a git repository, especially to speedup mono-repositories clone time"

inputs:
  patterns:
    description: >
      Git sparse checkout patterns.

      [Learn more by reading git documentation](https://git-scm.com/docs/git-sparse-checkout#Documentation/git-sparse-checkout.txt-emsetem)
    default: "*"
    required: true
  token:
    description: >
      Personal access token (PAT) used to fetch the repository. The PAT is configured
      with the local git config, which enables your scripts to run authenticated git
      commands. The post-job step removes the PAT.
      We recommend using a service account with the least permissions necessary.
      Also when generating a new PAT, select the least scopes necessary.
      [Learn more about creating and using encrypted secrets](https://help.github.com/en/actions/automating-your-workflow-with-github-actions/creating-and-using-encrypted-secrets)
    default: ${{ github.token }}
    required: true
  branch:
    required: true
    default: ${{ github.ref }}
    description: >
      The branch you want to check out
  sha:
    required: true
    default: ${{ github.sha }}
    description: >
      The sha1 of the head commit of the branch you want to check out

runs:
  using: "composite"
  steps:
    - name: "⚙ configure git"
      shell: bash
      run: |
        git version
        git config --global gc.auto 0

    - name: "⚡ git sparse checkout latest branch commit"
      shell: bash
      run: |
        REPO="https://${GITHUB_ACTOR}:${{ inputs.token }}@github.com/${GITHUB_REPOSITORY}.git"
        INPUT_BRANCH=${{inputs.branch}}
        BRANCH="${INPUT_BRANCH/#refs\/heads\//}"
        git clone --filter=blob:none --no-checkout --depth 1 --sparse $REPO .
        git sparse-checkout init --cone --sparse-index
        git sparse-checkout set ${{ inputs.patterns }}
        git -c protocol.version=2 fetch --no-tags --prune --progress --depth=1 origin +${{inputs.sha}}:refs/remotes/origin/${BRANCH}
        git checkout --progress --force -B $BRANCH refs/remotes/origin/$BRANCH

    - name: "👨‍💻 show what has been checked out"
      shell: bash
      run: |
        git log
        ls -lha