intermittent_typing_test.js

// Content page script

window.value = "init-value";
document.querySelector("input").addEventListener("input", () => {
  // Slow down the handler a bit
  for (var i = 0 ; i < 1000; i++) {
    console.log(i);
  }
  // Update the value that will be checked by the test
  window.value = document.querySelector("input").value;
});

// Puppeteer test

const text = 'text';
  for (let i = 1 ; i < 500 ; i++) {
    await page.type('input', text + i);
    const windowValue = await page.evaluate(() => window.value);
    if (windowValue != (text + i)) {
      throw new Error('Wrong value: ' + windowValue);
    }
    await page.evaluate(() => document.querySelector('input').value = '');
  }