ci: add rule for pr commit message

Author: ken4647

.github/workflows/commit.yml

@@ -0,0 +1,104 @@
+name: Custom Commit Message Validator
+
+on:
+  pull_request:
+    types: [opened, reopened, synchronize] # Triggers on PR open, reopen, or new commits pushed to the PR branch
+
+jobs:
+  validate_commit_messages:
+    runs-on: ubuntu-latest # Specifies the runner environment
+
+    permissions:
+      contents: read # Needed for checkout
+      pull-requests: read # Needed to fetch PR details and commit SHAs
+
+    steps:
+      - name: Checkout Repository
+        uses: actions/checkout@v4 # Action to checkout your repository
+        with:
+          fetch-depth: 0 # Fetches the entire history for git log operations. Crucial for retrieving full commit messages.
+
+      - name: Get PR Commits SHAs
+        id: get_pr_commits
+        run: |
+          # Use GitHub CLI to get all commit SHAs associated with the current Pull Request.
+          # This robustly gets the commits that are part of the PR's changes.
+          # The jq filter extracts the 'oid' (Object ID, which is the SHA) of each commit.
+          PR_COMMIT_SHAS=$(gh pr view ${{ github.event.pull_request.number }} --json commits --jq '.commits[].oid')
+
+          # Output the SHAs as a space-separated string.
+          # This variable will be accessible via steps.get_pr_commits.outputs.PR_COMMITS_LIST
+          echo "PR_COMMITS_LIST=${PR_COMMIT_SHAS}" >> "$GITHUB_OUTPUT"
+        env:
+          # GITHUB_TOKEN is automatically provided by GitHub Actions with sufficient permissions.
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Validate Each Commit Message
+        run: |
+          # Read the space-separated list of commit SHAs into a Bash array.
+          # IFS (Internal Field Separator) is set to space to split the string correctly.
+          IFS=' ' read -r -a commit_shas <<< "${{ steps.get_pr_commits.outputs.PR_COMMITS_LIST }}"
+
+          # Initialize a flag to track if any commit fails validation.
+          has_validation_failed=false
+
+          # Loop through each commit SHA.
+          for commit_sha in "${commit_shas[@]}"; do
+            echo "--- Checking commit: ${commit_sha} ---"
+
+            # Get the full commit message (subject + body).
+            # --format=%B gets the raw body (subject and body).
+            # -n 1 limits to the latest commit for the given SHA.
+            commit_message=$(git log --format=%B -n 1 "${commit_sha}")
+            echo "Message content:"
+            echo "${commit_message}"
+            echo "" # Add a newline for readability
+
+            # --- Validation Logic ---
+
+            # 1. Check for Conventional Commit format (type(scope)!: subject)
+            # This regex allows for an optional scope and an optional breaking change marker (!).
+            # Common types: feat, fix, docs, chore, style, refactor, perf, test, build, ci, revert
+            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 ${commit_sha} does not start with a conventional commit type (e.g., 'feat:', 'fix:'). Message: '${commit_message}'"
+              has_validation_failed=true
+              continue # Move to the next commit
+            fi
+
+            # Extract the first line (subject) for further checks.
+            commit_subject=$(echo "${commit_message}" | head -n 1)
+
+            # 2. Check subject line length (e.g., max 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}'"
+              # This is a warning, not a failure, adjust as needed.
+            fi
+
+            # 3. Check for empty line between subject and body (if body exists)
+            # Check if there's more than just the subject line.
+            if [[ $(echo "${commit_message}" | wc -l) -gt 1 ]]; then
+              # Check if the second line is empty.
+              # Use awk to get the second line and trim whitespace.
+              second_line=$(echo "${commit_message}" | awk 'NR==2 {print}' | xargs)
+              if [[ -n "${second_line}" ]]; then # If the second line is NOT empty
+                echo "::error file=COMMIT_MESSAGE::Commit ${commit_sha} is missing an empty line between the subject and body. Message: '${commit_message}'"
+                has_validation_failed=true
+                continue
+              fi
+            fi
+
+            # Add more custom validation rules here as needed:
+            # - Subject capitalization (e.g., must be lowercase)
+            # - Subject must not end with a period
+            # - Body line length limits
+            # - Required body content for certain types (e.g., 'fix:' requires a 'Fixes #ISSUE' line)
+
+          done # End of commit loop
+
+          # If any commit failed validation, exit with a non-zero status to fail the job.
+          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 commit messages in the PR passed validation."