What is the best way to handle asynchronous updates of elements in Playwright after clicking a button?

Answer

Handling Asynchronous Updates in Playwright

When dealing with asynchronous updates of elements after clicking a button in your web application, you might find that page.waitForSelector() doesn't work as expected. In such cases, you can use other methods like page.waitForFunction() or page.waitForTimeout() along with page.waitForSelector().

Using page.waitForFunction()

page.waitForFunction() waits until a JavaScript expression becomes true. For example:

import { test } from '@playwright/test';

test('wait for element update', async ({ page }) => {
  await page.goto('https://ray.run');
  await page.click('#myButton');
  await page.waitForFunction(() => document.querySelector('#myElement').textContent === 'Updated Text');
});

Using page.waitForTimeout()

page.waitForTimeout() introduces a delay between actions:

import { test } from '@playwright/test';

test('wait with timeout', async ({ page }) => {
  await page.goto('https://ray.run');
  await page.click('#myButton');
  await page.waitForTimeout(1000); // Wait 1 second
  await page.click('#anotherButton');
});

Remember that Playwright automatically waits for elements before performing actions, so you don't need to explicitly call these waiting methods unless your application has specific timing requirements.

In summary, to handle asynchronous updates of elements in Playwright after clicking a button, consider using waitForFunction() or introducing delays between actions using waitForTimeout().