Function responseLocationURL

deps/undici/src/lib/web/fetch/util.js:25–55

(response, requestFragment)

// https://fetch.spec.whatwg.org/#concept-response-location-url
function responseLocationURL (response, requestFragment) {
  // 1. If response’s status is not a redirect status, then return null.
  if (!redirectStatusSet.has(response.status)) {
    return null
  }

  // 2. Let location be the result of extracting header list values given
  // `Location` and response’s header list.
  let location = response.headersList.get('location', true)

  // 3. If location is a header value, then set location to the result of
  //    parsing location with response’s URL.
  if (location !== null && isValidHeaderValue(location)) {
    if (!isValidEncodedURL(location)) {
      // Some websites respond location header in UTF-8 form without encoding them as ASCII
      // and major browsers redirect them to correctly UTF-8 encoded addresses.
      // Here, we handle that behavior in the same way.
      location = normalizeBinaryStringToUtf8(location)
    }
    location = new URL(location, responseURL(response))
  }

  // 4. If location is a URL whose fragment is null, then set location’s
  // fragment to requestFragment.
  if (location && !location.hash) {
    location.hash = requestFragment
  }

  // 5. Return location.
  return location
}

/**
 * @see https://www.rfc-editor.org/rfc/rfc1738#section-2.2