Function waitForSelectorExistence

build-system/tasks/visual-diff/verifiers.js:211–220

* Wait until the CSS selector exists in the page or until timed out. * * Timeout is set to CSS_SELECTOR_RETRY_MS * CSS_SELECTOR_RETRY_ATTEMPTS ms. * * @param {!puppeteer.Page} page page to check the existence of the selector in. * @param {string} selector CSS selector. * @param {number} timeou

(page, selector, timeoutMillis)

 *    error with the message value set to the CSS selector.
 */
async function waitForSelectorExistence(page, selector, timeoutMillis) {
  const startTime = Date.now();
  do {
    if ((await page.$(selector)) !== null) {
      return true;
    }
    await sleep(CSS_SELECTOR_RETRY_MS);
  } while (Date.now() < startTime + timeoutMillis);
  throw new Error(selector);
}

module.exports = {
  waitForPageLoad,