loadUrl.ts

const loadUrl = async function(page, url, takeScreenshot) {
  let stepName = null;
  let domcontentloaded = false;

  try {
    stepName = new URL(url).hostname;
  } catch (error) {
    const errorString = `Error parsing url: ${url}.  ${error}`;
    log.error(errorString);
    /* If we fail to parse the URL, don't emit a metric with a stepName based on it.
       It may not be a legal CloudWatch metric dimension name and we may not have an alarms
       setup on the malformed URL stepName.  Instead, fail this step which will
       show up in the logs and will fail the overall canary and alarm on the overall canary
       success rate.
    */
    throw error;
  }

  await synthetics.executeStep(stepName, async function() {
    const sanitizedUrl = syntheticsLogHelper.getSanitizedUrl(url);

    /* You can customize the wait condition here. For instance, using 'networkidle2' or 'networkidle0' to load page completely.
       networkidle0: Navigation is successful when the page has had no network requests for half a second. This might never happen if page is constantly loading multiple resources.
       networkidle2: Navigation is successful when the page has no more then 2 network requests for half a second.
       domcontentloaded: It's fired as soon as the page DOM has been loaded, without waiting for resources to finish loading. Can be used and then add explicit await page.waitFor(timeInMs)
    */
    const response = await page.goto(url, { waitUntil: ['domcontentloaded'], timeout: 30000 });
    if (response) {
      domcontentloaded = true;
      const status = response.status();
      const statusText = response.statusText();

      logResponseString = `Response from url: ${sanitizedUrl}  Status: ${status}  Status Text: ${statusText}`;

      //If the response status code is not a 2xx success code
      if (response.status() < 200 || response.status() > 299) {
        throw `Failed to load url: ${sanitizedUrl} ${response.status()} ${response.statusText()}`;
      }
    } else {
      const logNoResponseString = `No response returned for url: ${sanitizedUrl}`;
      log.error(logNoResponseString);
      throw new Error(logNoResponseString);
    }
  });

  // Wait for 15 seconds to let page load fully before taking screenshot.
  if (domcontentloaded && takeScreenshot) {
    await page.waitFor(15000);
    await synthetics.takeScreenshot(stepName, 'loaded');
    await resetPage(page);
  }
};