commit_message.yml

name: Latest Commit Message Validation

on:
  pull_request:
    branches:
      - develop
      - main
      - 'release/**'
    types:
      - opened
      - edited
      - reopened
      - synchronize
  pull_request_target:
    branches:
      - develop
      - main
      - 'release/**'
    types:
      - opened
      - edited
      - reopened
      - synchronize
  push:
    branches:
      - develop
      - main
      - 'release/**'

jobs:
  validate_commit_messages:
    name: Validate Latest Commit Message
    runs-on: ubuntu-latest

    steps:
      - name: Checkout code
        uses: actions/checkout@v4
        with:
          fetch-depth: 0

      - name: Debug commit information
        run: |
          echo "=== DEBUG: Commit info ==="
          if [ "${{ github.event_name }}" = "pull_request" ]; then
            echo "PR event - checking latest commit only"
            echo "Latest commit: ${{ github.event.pull_request.head.sha }}"
            echo "Latest commit message:"
            git log --format="%B" -n 1 ${{ github.event.pull_request.head.sha }}
          else
            echo "Push event - checking pushed commit"
            echo "HEAD commit: $(git rev-parse HEAD)"
            echo "HEAD commit message:"
            git log --format="%B" -n 1 HEAD
          fi
          echo "=== End Debug ==="

      - name: Validate commit messages with custom script
        run: |
          #!/bin/bash
          set -e

          echo "=== Custom Commit Message Validation ==="

          # Enhanced validation for conventional commits
          # Allow detailed commit bodies while enforcing subject line format
          validate_commit() {
            local commit_sha="$1"
            local subject_line="$2"

            # Check if this is a merge commit - these have different rules
            local MERGE_PATTERN='^Merge (branch|pull request|remote-tracking branch)'
            if echo "$subject_line" | grep -qE "$MERGE_PATTERN"; then
              return 0  # Pass silently for merge commits
            fi

            # Pattern for conventional commit subject line
            # - Type is required
            # - Scope is optional
            # - Description must be at least 5 chars, max 100 for entire subject line
            # - Use imperative mood (no period at end)
            # - Allow upper or lowercase start (for acronyms like CLI, API, etc.)
            local SUBJECT_PATTERN='^(feat|fix|docs|style|refactor|perf|test|chore|build|ci)(\(.+\))?: [a-zA-Z].{4,}[^.]$'

            # Check subject line length (entire line should be <= 100 chars)
            if [ ${#subject_line} -gt 100 ]; then
              echo "❌ COMMIT $commit_sha FAILED:"
              echo "   Subject: '$subject_line'"
              echo "   Error: Subject line too long (${#subject_line} chars, max 100)"
              echo ""
              return 1
            fi

            # Check subject line format
            if echo "$subject_line" | grep -qE "$SUBJECT_PATTERN"; then
              return 0  # Pass silently
            else
              echo "❌ COMMIT $commit_sha FAILED:"
              echo "   Subject: '$subject_line'"
              echo "   Error: Subject line does not match conventional commit format"
              echo ""
              return 1
            fi
          }

          # Get commits to validate
          if [ "${{ github.event_name }}" = "pull_request" ]; then
            echo "Validating latest commit in PR: ${{ github.event.pull_request.head.sha }}"
            echo ""

            # Only validate the latest commit (HEAD of the PR branch)
            commit_sha="${{ github.event.pull_request.head.sha }}"
            commit_msg=$(git log --format="%s" -n 1 "$commit_sha")

            echo "Latest commit: $commit_sha"
            echo "Message: '$commit_msg'"
            echo ""

            if validate_commit "$commit_sha" "$commit_msg"; then
              echo "✅ Latest commit message is valid!"
            else
              echo ""
              echo "📋 Required Format: <type>(scope): <description>"
              echo ""
              echo "Optional detailed body and footer are allowed below the subject line."
              echo "Merge commits (starting with 'Merge branch/pull request') are automatically valid."
              echo ""
              echo "🏷️ Valid Types:"
              echo "• feat     - New feature"
              echo "• fix      - Bug fix"
              echo "• docs     - Documentation changes"
              echo "• style    - Code style changes (formatting, etc.)"
              echo "• refactor - Code refactoring"
              echo "• perf     - Performance improvements"
              echo "• test     - Adding or updating tests"
              echo "• chore    - Maintenance tasks"
              echo "• build    - Build system changes"
              echo "• ci       - CI/CD changes"
              echo ""
              echo "📏 Subject Line Requirements:"
              echo "• Total length: ≤100 characters"
              echo "• Description: ≥5 characters"
              echo "• Start with letter after colon (upper/lowercase both OK)"
              echo "• No trailing period"
              echo "• Be descriptive and clear"
              echo ""
              echo "✅ Good Examples:"
              echo "  feat(cli): add configuration validation"
              echo "  fix(routing): resolve path calculation bug"
              echo "  refactor(gui): CLI integration for entry point"
              echo "  docs: update installation guide with new requirements"
              echo ""
              echo "💡 Tip: Only the latest commit in your PR is checked."
              echo "    Use 'git commit --amend' to fix the message, or"
              echo "    'git rebase -i' to edit older commits if needed."
              echo ""
              exit 1
            fi
          else
            # Push event - validate the pushed commit
            echo "Validating push commit"
            commit_sha=$(git rev-parse HEAD)
            commit_msg=$(git log --format="%s" -n 1 HEAD)

            if validate_commit "$commit_sha" "$commit_msg"; then
              echo "✅ Commit message is valid!"
            else
              exit 1
            fi
          fi