Function normalizeHeaders

deps/undici/src/lib/util/cache.js:37–65

* @param {Record } * @returns {Record }

(opts)

 * @returns {Record<string, string[] | string>}
 */
function normalizeHeaders (opts) {
  let headers
  if (opts.headers == null) {
    headers = {}
  } else if (typeof opts.headers === 'object') {
    headers = {}

    if (hasSafeIterator(opts.headers)) {
      for (const x of opts.headers) {
        if (!Array.isArray(x)) {
          throw new Error('opts.headers is not a valid header map')
        }
        const [key, val] = x
        if (typeof key !== 'string' || typeof val !== 'string') {
          throw new Error('opts.headers is not a valid header map')
        }
        headers[key.toLowerCase()] = val
      }
    } else {
      for (const key of Object.keys(opts.headers)) {
        headers[key.toLowerCase()] = opts.headers[key]
      }
    }
  } else {
    throw new Error('opts.headers is not an object')
  }

  return headers
}

/**
 * @param {any} key