code: async function getChangeType() {
    const subjects = await exec('git log upstream/master.. --format=%s');
  
    for (const subject of subjects.split('\n')) {
      if (subject.startsWith('feat')) {
        return 'minor';
      }
  
      if (subject.startsWith('fix') || subject.startsWith('perf') || subject.startsWith('refactor')) {
        return 'patch';
      }
    }
  
    return undefined;
  }
docs: Checks commit messages to determine change type
  @returns {Promise<boolean>}