pre-commit.yml

name: pre-commit

on:
  pull_request:
  push:
    branches:
      - main
jobs:
  pre-commit:
    name: pre-commit
    runs-on: ubuntu-latest
    steps:
      - name: Checkout repo
        uses: actions/checkout@v4
        with:
          fetch-depth: 0
          clean: false
          ref: ${{ github.head_ref }}

      - name: Set up Python
        uses: actions/setup-python@v5
        with:
          python-version: '3.8'
          cache: 'pip'
      # N.B. we don't need all the dependencies to run the code for just pre-commit
      - name: Install dependencies
        run: |
          python -m pip install --upgrade pip
          pip install -r requirements-dev.txt

      - name: Cache pre-commit envs
        uses: actions/cache@v2
        with:
          path: ~/.cache/pre-commit
          key: ${{ runner.os }}-pre-commit-${{ hashFiles('**/requirements-dev.txt') }}-${{ hashFiles('**/.pre-commit-config.yaml') }}
          restore-keys: |
            ${{ runner.os }}-pre-commit-${{ hashFiles('**/requirements-dev.txt') }}-
            ${{ runner.os }}-pre-commit-

      - name: Run pre-commit
        env:
          REF_BEFORE: ${{ github.event_name == 'pull_request' && github.base_ref || github.event.before }}
          REF_AFTER: ${{ github.event_name == 'pull_request' && github.head_ref || github.event.after }}
        run: |
          # make sure dropped commits are fetched
          git fetch origin $REF_BEFORE:$REF_BEFORE
          # if it's a push, check since the common ancestor of the before/after (for forced pushes)
          if [[ "${{ github.event_name }}" == "push" ]]; then
            export REF_BEFORE=$(git merge-base $REF_BEFORE $REF_AFTER)
          fi
          # make sure gitlint knows which commits to lint
          export GITLINT_COMMITS=$REF_BEFORE..$REF_AFTER
          # run pre-commit
          pre-commit run --from-ref $REF_BEFORE --to-ref $REF_AFTER