Function fetchDocument

src/document-fetcher.js:22–44

(win, input, opt_init)

 * @ignore
 */
export function fetchDocument(win, input, opt_init) {
  let init = setupInit(opt_init, 'text/html');
  init = setupAMPCors(win, input, init);
  input = setupInput(win, input, init);
  const ampdocService = Services.ampdocServiceFor(win);
  const ampdocSingle = ampdocService.isSingleDoc()
    ? ampdocService.getSingleDoc()
    : null;
  init.responseType = 'document';
  return getViewerInterceptResponse(win, ampdocSingle, input, init).then(
    (interceptorResponse) => {
      if (interceptorResponse) {
        return interceptorResponse
          .text()
          .then((body) => new DOMParser().parseFromString(body, 'text/html'));
      }
      return xhrRequest(input, init).then((resp) => {
        const {xhr} = resp;
        return xhr.responseXML;
      });
    }
  );
}

/**
 *