reusable-update-pre-commit.yml

name: Reusable Update pre-commit
# Update pre-commit config and create PR if changes are detected
# OG author: Christoph Fröhlich <christoph.froehlich@ait.ac.at>[ROS2 Control CI]
# UoE editor: Alejandro Bordallo <alex.bordallo@ed.ac.uk>

on:
  workflow_call:
    inputs:
      ref_for_scheduled_build:
        description: |
          'Reference on which the repo should be checkout for scheduled build.
          Usually is this name of a branch or a tag.'
        default: ''
        required: false
        type: string
    secrets:
      precommit-pr-token:
        description: 'PAT from GreatAlexander for PR auto-approval'
        required: true

jobs:
  auto_update_and_create_pr:
    runs-on: ubuntu-latest
    env:
      # this will be src/{repo-owner}/{repo-name}
      path: src/${{ github.repository }}

    steps:
      - name: Checkout code
        uses: actions/checkout@v4
        with:
          fetch-depth: 0
          path: ${{ env.path }}
          ref: ${{ github.event.inputs.ref_for_scheduled_build }}

      - name: Install pre-commit
        run: |
          sudo apt-get install -qq python3-venv
          python3 -m venv .venv
          source .venv/bin/activate
          python3 -m pip install pre-commit

      - name: Auto-update with pre-commit
        run: |
          source .venv/bin/activate
          cd ${{ env.path }}
          pre-commit autoupdate || true  # Ignoring errors

      - name: Check for changes
        id: git_status
        run: |
          cd ${{ env.path }}
          git diff --quiet && echo "changed=false" >> $GITHUB_OUTPUT || echo "changed=true" >> $GITHUB_OUTPUT

      - name: There are changes
        id: git_diff
        if: steps.git_status.outputs.changed == 'true'
        run: |
          cd ${{ env.path }}
          {
            echo 'PR_COMMIT_DIFF<<EOF'
            git diff --unified=1
            echo EOF
          } >> "$GITHUB_ENV"
          git diff --exit-code || true

      - name: No changes!
        if: steps.git_status.outputs.changed == 'false'
        run: |
          echo "No changes detected"

      - name: Create Pull Request
        id: cpr
        if: steps.git_status.outputs.changed == 'true'
        uses: peter-evans/create-pull-request@v7
        with:
          token: ${{ secrets.GITHUB_TOKEN }}
          branch: auto-update-${{ github.event.inputs.ref_for_scheduled_build }}
          base: main
          commit-message: |
            Bump version of pre-commit hooks

            ```diff
            ${{ env.PR_COMMIT_DIFF }}
            ```
          title: Bump version of pre-commit hooks
          body: |
            This pull request contains auto-updated files of the pre-commit config.

            ```diff
            ${{ env.PR_COMMIT_DIFF }}
            ```
          delete-branch: true
          draft: false
          path: ${{ env.path }}

      - name: Enable Pull Request Automerge
        if: steps.cpr.outputs.pull-request-operation == 'created'
        run: |
          cd ${{ env.path }}
          gh pr merge --squash --auto "${{ steps.cpr.outputs.pull-request-number }}"
        env:
          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}

      - name: Auto approve
        if: steps.cpr.outputs.pull-request-operation == 'created'
        run: |
          cd ${{ env.path }}
          gh pr review --approve "${{ steps.cpr.outputs.pull-request-number }}"
        env:
          GH_TOKEN: ${{ secrets.precommit-pr-token }}