commitlint.yml

name: Commitlint

on:
  pull_request:
    types: [opened, edited, synchronize, reopened, ready_for_review]

permissions:
  pull-requests: read

jobs:
  commitlint:
    name: Commitlint
    runs-on: ubuntu-24.04
    timeout-minutes: 5
    steps:
      - name: Validate commit messages
        uses: actions/github-script@3a2844b7e9c422d3c10d287c895573f7108da1b3 # v9.0.0
        env:
          TRUSTED_AUTOMATION_USERS: dependabot[bot]
        with:
          script: |
            const pr = context.payload.pull_request;
            const trustedAutomationUsers = (process.env.TRUSTED_AUTOMATION_USERS || '')
              .split(',')
              .map((login) => login.trim())
              .filter(Boolean);
            if (trustedAutomationUsers.includes(pr.user.login)) {
              core.info(`Commit message validation is delegated for trusted automation @${pr.user.login}.`);
              return;
            }
            const allowedTypes = new Set([
              'feat',
              'fix',
              'docs',
              'style',
              'refactor',
              'test',
              'chore',
              'perf',
              'revert',
            ]);

            const commits = await github.paginate(github.rest.pulls.listCommits, {
              owner: context.repo.owner,
              repo: context.repo.repo,
              pull_number: pr.number,
              per_page: 100,
            });

            const failures = [];

            for (const commit of commits) {
              const shortSha = commit.sha.slice(0, 7);
              const subject = commit.commit.message.split('\n')[0];
              const match = subject.match(/^([a-z]+)(?:\(([a-z0-9._-]+)\))?(!)?: (.+)$/u);

              if (subject.length > 72) {
                failures.push(`${shortSha}: first line is ${subject.length} chars; max is 72`);
                continue;
              }

              if (!match) {
                failures.push(`${shortSha}: '${subject}' is not Conventional Commits format`);
                continue;
              }

              const [, type, , , description] = match;

              if (!allowedTypes.has(type)) {
                failures.push(`${shortSha}: unsupported type '${type}'`);
              }

              if (/^[A-Z]/.test(description)) {
                failures.push(`${shortSha}: subject must not start with a capital letter`);
              }

              if (description.endsWith('.')) {
                failures.push(`${shortSha}: subject must not end with a period`);
              }
            }

            if (failures.length > 0) {
              core.setFailed(`Commit message validation failed:\n- ${failures.join('\n- ')}`);
            } else {
              core.info('All commit messages follow Conventional Commits.');
            }