Function httpRedirectFetch

deps/undici/src/lib/web/fetch/index.js:1252–1393

(fetchParams, response)

// https://fetch.spec.whatwg.org/#http-redirect-fetch
function httpRedirectFetch (fetchParams, response) {
  // 1. Let request be fetchParams’s request.
  const request = fetchParams.request

  // 2. Let actualResponse be response, if response is not a filtered response,
  // and response’s internal response otherwise.
  const actualResponse = response.internalResponse
    ? response.internalResponse
    : response

  // 3. Let locationURL be actualResponse’s location URL given request’s current
  // URL’s fragment.
  let locationURL

  try {
    locationURL = responseLocationURL(
      actualResponse,
      requestCurrentURL(request).hash
    )

    // 4. If locationURL is null, then return response.
    if (locationURL == null) {
      return response
    }
  } catch (err) {
    // 5. If locationURL is failure, then return a network error.
    return Promise.resolve(makeNetworkError(err))
  }

  // 6. If locationURL’s scheme is not an HTTP(S) scheme, then return a network
  // error.
  if (!urlIsHttpHttpsScheme(locationURL)) {
    return Promise.resolve(makeNetworkError('URL scheme must be a HTTP(S) scheme'))
  }

  // 7. If request’s redirect count is 20, then return a network error.
  if (request.redirectCount === 20) {
    return Promise.resolve(makeNetworkError('redirect count exceeded'))
  }

  // 8. Increase request’s redirect count by 1.
  request.redirectCount += 1

  // 9. If request’s mode is "cors", locationURL includes credentials, and
  // request’s origin is not same origin with locationURL’s origin, then return
  //  a network error.
  if (
    request.mode === 'cors' &&
    (locationURL.username || locationURL.password) &&
    !sameOrigin(request, locationURL)
  ) {
    return Promise.resolve(makeNetworkError('cross origin not allowed for request mode "cors"'))
  }

  // 10. If request’s response tainting is "cors" and locationURL includes
  // credentials, then return a network error.
  if (
    request.responseTainting === 'cors' &&