Function scrollThroughPage

src/utils.ts:653–683

(page: Page)

 * @param page Page
 */
export const scrollThroughPage = async (page: Page) => {
  const viewport = (await page.viewport()) || {
    height: 480,
    width: 640,
  }; // default Puppeteer viewport

  await page.evaluate((bottomThreshold) => {
    const scrollInterval = 100;
    const scrollStep = Math.floor(window.innerHeight / 2);

    function bottomPos() {
      return window.pageYOffset + window.innerHeight;
    }

    return new Promise((resolve) => {
      function scrollDown() {
        window.scrollBy(0, scrollStep);

        if (document.body.scrollHeight - bottomPos() < bottomThreshold) {
          window.scrollTo(0, 0);
          setTimeout(resolve, 500);
          return;
        }

        setTimeout(scrollDown, scrollInterval);
      }

      scrollDown();
    });
  }, viewport.height);
};

export const noop = (): void => {};