Function getPreconnectIframe

test/unit/test-preconnect.js:28–54

(detectFeatures = false)

  const javascriptUrlPrefix = 'javascript';

  function getPreconnectIframe(detectFeatures = false) {
    return createIframePromise().then((iframe) => {
      iframeClock = fakeTimers.withGlobal(iframe.win).install();
      if (detectFeatures) {
        setPreconnectFeaturesForTesting(null);
      } else {
        setPreconnectFeaturesForTesting({
          preload: preloadSupported,
          preconnect: preconnectSupported,
        });
      }

      const platform = {
        isSafari: () => !!isSafari,
      };
      iframe.win.__AMP_SERVICES['platform'] = {obj: platform, ctor: Object};
      sandbox.stub(Services, 'platformFor').returns(platform);

      installPreconnectService(iframe.win);
      preconnect = Services.preconnectFor(iframe.win);

      ampdoc = {
        whenFirstVisible: () => visiblePromise,
      };
      return iframe;
    });
  }

  beforeEach(() => {
    sandbox = env.sandbox;