module.exports = validateAuth

function validateAuth (auth) {
  if (typeof auth === 'string') {
    return
  }

  if (typeof auth === 'function') {
    return
  }

  if (auth.username && auth.password) {
    return
  }

  if (auth.clientId && auth.clientSecret) {
    return
  }

  throw new Error(`Invalid "auth" option: ${JSON.stringify(auth)}`)
}