commit_message_validation.yml

name: validate git commit messages

on:
  pull_request:
    branches: [ main, develop ]

jobs:
  commit_message_validation:
    name: validate git commit messages
    runs-on: ubuntu-latest
    steps:
      - name: Checkout repository
        uses: actions/checkout@v4
        with:
          fetch-depth: 0
          ref: '${{ github.event.pull_request.base.ref }}'

      - name: Execute message validation
        run: |
          # Checkout branch
          git checkout -q ${{ github.event.pull_request.head.ref }}
          # Set variables
          BASE_BRANCH=${{ github.event.pull_request.base.ref }}
          msg_regex='MAT-[0-9]+\s.*'
          # This list permits some commits
          commit_static_permit_list="(^Merge pull request \#)|(^Merge branch)|(^Revert \")"
          # Initialize invalidCommit as false, will be set to true by any invalid commits
          invalidCommit=false
          CURRENT_BRANCH=$(git branch | grep ^\* | cut -d "*" -f 2 | cut -d " " -f 2)
          # Find hash of commit most common ancestor, e.g. where branch began
          BRANCH_MERGE_BASE=$(git merge-base ${BASE_BRANCH} ${CURRENT_BRANCH})
          # Find all commits since common ancestor
          BRANCH_COMMITS=$(git rev-list ${BRANCH_MERGE_BASE}..HEAD)
          # Check every commit message since ancestor for regex match
          for commit in $BRANCH_COMMITS; do
            # Check if ticket in static permit-list for non-Jira commit_sha
            if $(git log --max-count=1 --format=%B $commit | grep -iqE "$commit_static_permit_list"); then
              : #If commit matches regex, commit is valid, do nothing
            elif git log --max-count=1 --format=%B $commit | tr '[a-z]' '[A-Z]' | grep -iqE "$msg_regex"; then
              : #If commit matches regex, commit is valid, do nothing
            else
              # If commit doesn't match regex, commit isn't valid, print commit info
              echo "************"
              printf "Invalid commit message: \"%s\" and hash: %s\n" "$(git log --max-count=1 --format=%B $commit)" "$commit"
              echo "************"
              # Set this variable to trigger rejection if any commit fails regex
              invalidCommit=true
            fi
          done

          # If any commit are invalid, print reject message
          if [ "$invalidCommit" == true ]; then
            echo "Your push was rejected because at least one commit message on this branch is invalid"
            echo "Please fix the commit message(s) and push again."
            echo "https://help.github.com/en/articles/changing-a-commit-message"
            echo "************"
            exit 1
          elif [ "$invalidCommit" == false ]; then
            echo "************"
            echo "All commits are valid"
            echo "************"
            exit 0
          fi