/***
Usage:
  function saveUser(userInfo) {
    return pipe(
      validate,
      normalize,
      persist
    )(userInfo)
  }

  function validate(
    id,
    firstName,
    lastName,
    email = requiredParam(),
    username = requiredParam(),
    pass = requiredParam(),
    address,
    ...rest
  ) {
    // do some validation
    return {
      id,
      firstName,
      lastName,
      email,
      username,
      pass,
      address,
      ...rest
    }
  }

  function normalize(
    email,
    username,
    ...rest
  ) {
    // do some normalizing
    return {
      email,
      username,
      ...rest
    }
  }

  async function persist({
    upsert = true,
    ...info
  }) {
    // save userInfo to the DB
    return {
      operation,
      status,
      saved: info
    }
  }
***/

function pipe(...fns) {
  return param => fns.reduce(
    (result, fn) => fn(result),
    param
  )
}

function requiredParam (param) {
  const requiredParamError = new Error(
   `Required parameter, "${param}" is missing.`
  )
// preserve original stack trace
  if (typeof Error.captureStackTrace === ‘function’) {
    Error.captureStackTrace(
      requiredParamError,
      requiredParam
    )
  }
  throw requiredParamError
}