commit.yml

name: Custom Commit Message Validator




on:

  pull_request:

    types: [opened, reopened, synchronize]




jobs:

  validate_COMMIT_MESSAGEs:

    runs-on: ubuntu-latest




    permissions:

      contents: read

      pull-requests: read




    steps:

      - name: Checkout Repository

        uses: actions/checkout@v4

        with:

          fetch-depth: 0




      - name: Get PR Commits SHAs

        id: get_pr_commits

        run: |

          # Fetch all commit SHAs associated with the current Pull Request



          PR_COMMIT_SHAS=$(gh pr view ${{ github.event.pull_request.number }} --json commits --jq '[.commits[].oid] | join(" ")')




          echo "PR_COMMITS_LIST=${PR_COMMIT_SHAS}" >> "$GITHUB_OUTPUT"

        env:


          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}




      - name: Validate Each Commit Message

        env:

          TARGET_DATE: "2025-07-22"  # Only check commits after this date

          SKIP_KEYWORDS: "Merge,Revert,Release"  # Comma-separated keywords to skip validation

        run: |

          # Read commit SHAs into array


          IFS=' ' read -r -a commit_shas <<< "${{ steps.get_pr_commits.outputs.PR_COMMITS_LIST }}"



          has_validation_failed=false



          # Convert skip keywords to array

          IFS=',' read -r -a skip_keywords <<< "$SKIP_KEYWORDS"

          

          for commit_sha in "${commit_shas[@]}"; do

            echo "--- Checking commit: ${commit_sha} ---"

            

            # Get commit timestamps for date filtering

            COMMIT_DATE_UNIX=$(git log -n 1 --format=%at "${commit_sha}")

            TARGET_DATE_UNIX=$(date -d "${TARGET_DATE}" +"%s")

            COMMIT_DATE_HUMAN=$(git log -n 1 --format=%ad --date=iso-strict "${commit_sha}")



            # Skip older commits

            if (( COMMIT_DATE_UNIX < TARGET_DATE_UNIX )); then

              echo "Skipping commit ${commit_sha} (Date: ${COMMIT_DATE_HUMAN}) as it is older than ${TARGET_DATE}."

              continue

            fi



            echo "Processing commit ${commit_sha} (Date: ${COMMIT_DATE_HUMAN}) as it is on or after ${TARGET_DATE}."

            COMMIT_MESSAGE=$(git log --format=%B -n 1 "${commit_sha}")



            echo "Message content:"

            echo "${COMMIT_MESSAGE}"

            echo ""



            # Check for skip keywords

            skip_this_commit=false

            for keyword in "${skip_keywords[@]}"; do

              # Trim whitespace from keyword

              trimmed_keyword=$(echo "$keyword" | xargs)

              

              if [[ -n "$trimmed_keyword" ]] && 

                 [[ "${COMMIT_MESSAGE}" == *"$trimmed_keyword"* ]]; then

                echo "Skipping validation for commit ${commit_sha} due to skip keyword: ${trimmed_keyword}"

                skip_this_commit=true

                break

              fi

            done

            

            if [ "$skip_this_commit" = true ]; then

              continue

            fi



            # --- Validation Logic Start ---

            

            # 1. Check Conventional Commit format

            if [[ ! "${COMMIT_MESSAGE}" =~ ^(feat|fix|docs|chore|style|refactor|perf|test|build|ci|revert)(\([a-zA-Z0-9_-]+\))?(!?): ]]; then

              echo "::error file=COMMIT_MESSAGE::Commit ${commit_sha} does not start with a conventional commit type. Message: '${COMMIT_MESSAGE}'"

              has_validation_failed=true

              continue

            fi



            # Extract commit subject (first line)

            commit_subject=$(echo "${COMMIT_MESSAGE}" | head -n 1)



            # 2. NEW: Check minimum subject length (15 characters)

            if [[ ${#commit_subject} -lt 15 ]]; then

              echo "::error file=COMMIT_MESSAGE::Commit ${commit_sha} subject is too short (min 15 characters). Length: ${#commit_subject}. Subject: '${commit_subject}'"

              has_validation_failed=true

              continue

            fi



            # 3. Check maximum subject length (72 characters)

            if [[ ${#commit_subject} -gt 72 ]]; then

              echo "::warning file=COMMIT_MESSAGE::Commit ${commit_sha} subject line exceeds 72 characters. Length: ${#commit_subject}. Subject: '${commit_subject}'"


            fi



            # 4. Check empty line between subject and body

            if [[ $(echo "${COMMIT_MESSAGE}" | wc -l) -gt 1 ]]; then

              second_line=$(echo "${COMMIT_MESSAGE}" | awk 'NR==2 {print}' | xargs)

              if [[ -n "${second_line}" ]]; then

                echo "::error file=COMMIT_MESSAGE::Commit ${commit_sha} is missing an empty line between subject and body. Message: '${COMMIT_MESSAGE}'"




                has_validation_failed=true

                continue

              fi

            fi



          done









          # Fail job if any validation errors occurred

          if [ "$has_validation_failed" = true ]; then

            echo "::error::One or more commit messages failed validation. Please review the errors above."

            exit 1

          fi



          echo "All relevant commit messages in the PR passed validation."