commit.yml

# Copyright (C) 2020-2021 TotalCross Global Mobile Platform Ltda
# Copyright (C) 2022-2026 Amalgam Solucoes em TI Ltda
#
# SPDX-License-Identifier: LGPL-2.1-only

name: Commit Message Check

on:
  push:
    branches:
      - master
  pull_request:

jobs:
  check-commit-message:
    name: Validate commit messages
    runs-on: ubuntu-latest

    steps:
      - name: Check out repository
        uses: actions/checkout@v6
        with:
          fetch-depth: 0

      - name: Validate commit messages in range
        env:
          EVENT_NAME: ${{ github.event_name }}
          PUSH_BEFORE: ${{ github.event.before }}
          PUSH_AFTER: ${{ github.sha }}
          PR_BASE_SHA: ${{ github.event.pull_request.base.sha }}
          PR_HEAD_SHA: ${{ github.event.pull_request.head.sha }}
        run: |
          python3 <<'PY'
          import os
          import re
          import subprocess
          import sys

          TITLE_FORMAT = re.compile(
              r'^(fix|feat|refactor|perf|style|test|docs|build|ci|chore|revert)'
              r'(!\([A-Za-z0-9_-]+(,[a-z0-9_-]+)?\)|'
              r'\([A-Za-z0-9_-]+(,[a-z0-9_-]+)?\)!?): [a-z0-9 ].*$'
          )
          TITLE_CAPITALIZATION = re.compile(r'^[^A-Z]')
          TITLE_WORD_COUNT = re.compile(r'^[^ ]+([ \t]+[^ ]+){2,}$', re.S)
          TITLE_LENGTH = re.compile(r'^([^\n]{1,80})(\n.*)?$', re.S)
          BLANK_LINE = re.compile(r'^[^\n]+(\n\n.+)?$', re.S)
          MARKDOWN_LINK = re.compile(r'\[([^\]]*)\]\([^)]+\)')

          def run(*args):
            return subprocess.check_output(args, text=True).strip()

          def commit_range():
            event_name = os.environ["EVENT_NAME"]
            if event_name == "pull_request":
              head = os.environ["PR_HEAD_SHA"]
              base = run("git", "merge-base", os.environ["PR_BASE_SHA"], head)
              return base, head

            before = os.environ["PUSH_BEFORE"]
            after = os.environ["PUSH_AFTER"]
            if before == "0000000000000000000000000000000000000000":
              return "", after
            return before, after

          def list_commits(base, head):
            if base:
              output = run("git", "rev-list", f"{base}..{head}")
            else:
              output = run("git", "rev-list", head)
            return [line for line in output.splitlines() if line]

          def read_message(commit):
            return subprocess.check_output(
                ["git", "show", "-s", "--format=%B", commit],
                text=True,
            ).rstrip("\n")

          def body_line_length(line):
            return len(MARKDOWN_LINK.sub(r"\1", line))

          def validate(commit, message):
            title = message.split("\n", 1)[0]
            failures = []

            if not TITLE_FORMAT.match(title):
              failures.append("Invalid commit title format.")
            if not TITLE_CAPITALIZATION.match(title):
              failures.append("Commit title must not start with an uppercase letter.")
            if not TITLE_WORD_COUNT.match(title):
              failures.append("Commit title must contain at least 3 words.")
            if not TITLE_LENGTH.match(message):
              failures.append("Commit title must be 80 characters or less.")
            if title.endswith("."):
              failures.append("Commit title must not end with a period.")
            if not BLANK_LINE.match(message):
              failures.append(
                  "If a commit body is present, it must be separated from the title by a blank line."
              )
            if any(body_line_length(line) > 80 for line in message.split("\n")[1:]):
              failures.append(
                  "Each line in the commit body must be 80 characters or less, "
                  "excluding Markdown link URLs."
              )

            return title, failures

          base, head = commit_range()
          commits = list_commits(base, head)
          range_label = f"{base}..{head}" if base else head
          print(f"Validating commit messages in range: {range_label}")
          print(f"Event: {os.environ['EVENT_NAME']}")

          if not commits:
            print("No commits to validate.")
            sys.exit(0)

          invalid = []
          for commit in reversed(commits):
            message = read_message(commit)
            title, failures = validate(commit, message)
            if failures:
              invalid.append((commit, title, failures))

          if invalid:
            print(f"Commit message validation failed for {len(invalid)} commit(s).\n")
            print("Commits outside the expected format:")
            for commit, title, failures in invalid:
              print(f"- {commit} {title}")
              for failure in failures:
                print(f"    - {failure}")
                print(f"::error title={commit[:10]} {title}::{failure}")
              print()
            sys.exit(1)

          print(f"Validated {len(commits)} commit message(s).")
          PY