/** @type {(k: string) => string} */
const required = k => {
  if (!process.env[k]) {
    throw new Error(`Required environment variable not set: ${k}`)
  }
  return process.env[k]
}

/** @type {(k: string) => Array<string>} */
const array = k => {
  const vals = required(k)
    .split(',')
    .flatMap(s => (!s.trim() ? [] : [s.trim()]))
  if (vals.length === 0) {
    throw new Error(`At least 1 value required: ${k}`)
  }
  return vals
}

export default { required, array }