module Cucumber::CiEnvironment

def detect_revision(ci_environment, env)
  if env['GITHUB_EVENT_NAME'] == 'pull_request'
    raise StandardError('GITHUB_EVENT_PATH not set') unless env['GITHUB_EVENT_PATH']
    event = JSON.parse(IO.read(env['GITHUB_EVENT_PATH']))
    revision = event['pull_request']['head']['sha'] rescue nil
    raise StandardError("Could not find .pull_request.head.sha in #{env['GITHUB_EVENT_PATH']}:\n#{JSON.pretty_generate(event)}") if revision.nil?
    return revision
  end
  return evaluate(ci_environment['git']['revision'], env)
end