puppeteerでalertをチェックするやつ

index.js

const puppeteer = require('puppeteer');

(async() => {
  const url = 'http://';
  const browser = await puppeteer.launch();
  const page = await browser.newPage();
  await page.goto(url, {waitUntil: 'networkidle'});
  page.on('dialog', dialog => {
    console.log(dialog.message());
    dialog.accept();
  })
  await page.focus('input');
  await page.type('<script>alert(1)</script>');
  // await page.type('Hello');
  await page.click('button');
  await page.waitForSelector('script');
  const result = await page.evaluate(() => {
    return Promise.resolve(document.body.innerHTML);
  })
  console.log(result);

  browser.close();
})();