Migrating from Puppeteer
Migration Principles
This guide describes migration to Playwright Library and Playwright Test from Puppeteer. The APIs have similarities, but Playwright offers much more possibilities for web testing and cross-browser automation.
- Most Puppeteer APIs can be used as is
- The use of ElementHandle is discouraged, use Locator objects and web-first assertions instead.
- Playwright is cross-browser
- You probably don't need explicit wait
Cheat Sheet
Puppeteer | Playwright Library |
---|---|
await puppeteer.launch() | await playwright.chromium.launch() |
puppeteer.launch({product: 'firefox'}) | await playwright.firefox.launch() |
WebKit is not supported by Puppeteer | await playwright.webkit.launch() |
await browser.createIncognitoBrowserContext(...) | await browser.newContext(...) |
await page.setViewport(...) | await page.setViewportSize(...) |
await page.waitForXPath(XPathSelector) | await page.waitForSelector(XPathSelector) |
await page.waitForNetworkIdle(...) | await page.waitForLoadState('networkidle') |
await page.$eval(...) | Assertions can often be used instead to verify text, attribute, class... |
await page.$(...) | Discouraged, use Locators instead |
await page.$x(xpath_selector) | Discouraged, use Locators instead |
No methods dedicated to checkbox or radio input | await page.locator(selector).check() await page.locator(selector).uncheck() |
await page.click(selector) | await page.locator(selector).click() |
await page.focus(selector) | await page.locator(selector).focus() |
await page.hover(selector) | await page.locator(selector).hover() |
await page.select(selector, values) | await page.locator(selector).selectOption(values) |
await page.tap(selector) | await page.locator(selector).tap() |
await page.type(selector, ...) | await page.locator(selector).fill(...) |
await page.waitForFileChooser(...) await elementHandle.uploadFile(...) | await page.locator(selector).setInputFiles(...) |
await page.cookies([...urls]) | await browserContext.cookies([urls]) |
await page.deleteCookie(...cookies) | await browserContext.clearCookies() |
await page.setCookie(...cookies) | await browserContext.addCookies(cookies) |
page.on(...) | page.on(...) In order to intercept and mutate requests, see page.route() |
page.waitForNavigation
and page.waitForSelector
remain, but in many cases will not be necessary due to auto-waiting.
The use of ElementHandle is discouraged, use Locator objects and web-first assertions instead.
Locators are the central piece of Playwright's auto-waiting and retry-ability. Locators are strict. This means that all operations on locators that imply some target DOM element will throw an exception if more than one element matches a given selector.
Examples
Automation example
Puppeteer:
const puppeteer = require('puppeteer');
(async () => {
const browser = await puppeteer.launch();
const page = await browser.newPage();
await page.setViewport({ width: 1280, height: 800 });
await page.goto('https://playwright.dev/', {
waitUntil: 'networkidle2',
});
await page.screenshot({ path: 'example.png' });
await browser.close();
})();
Line-by-line migration to Playwright:
const { chromium } = require('playwright'); // 1
(async () => {
const browser = await chromium.launch();
const page = await browser.newPage(); // 2
await page.setViewportSize({ width: 1280, height: 800 }); // 3
await page.goto('https://playwright.dev/', {
waitUntil: 'networkidle', // 4
});
await page.screenshot({ path: 'example.png' });
await browser.close();
})();
Migration highlights (see inline comments in the Playwright code snippet):
- Each Playwright Library file has explicit import of
chromium
. Other browserswebkit
orfirefox
can be used. - For browser state isolation, consider browser contexts
setViewport
becomessetViewportSize
networkidle2
becomesnetworkidle
. Please note that in most cases it is not useful, thanks to auto-waiting.
Test example
Puppeteer with Jest:
import puppeteer from 'puppeteer';
describe('Playwright homepage', () => {
let browser;
let page;
beforeAll(async () => {
browser = await puppeteer.launch();
page = await browser.newPage();
});
it('contains hero title', async () => {
await page.goto('https://playwright.dev/');
await page.waitForSelector('.hero__title');
const text = await page.$eval('.hero__title', e => e.textContent);
expect(text).toContain('Playwright enables reliable end-to-end testing'); // 5
});
afterAll(() => browser.close());
});
Line-by-line migration to Playwright Test:
import { test, expect } from '@playwright/test'; // 1
test.describe('Playwright homepage', () => {
test('contains hero title', async ({ page }) => { // 2, 3
await page.goto('https://playwright.dev/');
const titleLocator = page.locator('.hero__title'); // 4
await expect(titleLocator).toContainText( // 5
'Playwright enables reliable end-to-end testing'
);
});
});
- Each Playwright Test file has explicit import of the
test
andexpect
functions - Test function is marked with
async
- Playwright Test is given a
page
as one of its parameters. This is one of the many useful fixtures in Playwright Test. Playwright Test creates an isolated Page object for each test. However, if you'd like to reuse a single Page object between multiple tests, you can create your own in test.beforeAll() and close it in test.afterAll(). - Locator creation with page.locator() is one of the few methods that is sync.
- Use assertions to verify the state instead of
page.$eval()
.
Testing
To improve testing, it is advised to use Locators and web-first Assertions. See Writing Tests
It is common with Puppeteer to use page.evaluate()
or page.$eval()
to inspect an ElementHandle and extract the value of text content, attribute, class... Web-first Assertions offers several matchers for this purpose, it is more reliable and readable.
Playwright Test is our first-party recommended test runner to be used with Playwright. It provides several features like Page Object Model, parallelism, fixtures or reporters.
Playwright Test Super Powers
Once you're on Playwright Test, you get a lot!
- Full zero-configuration TypeScript support
- Run tests across all web engines (Chrome, Firefox, Safari) on any popular operating system (Windows, macOS, Ubuntu)
- Full support for multiple origins, (i)frames, tabs and contexts
- Run tests in isolation in parallel across multiple browsers
- Built-in test artifact collection
You also get all these ✨ awesome tools ✨ that come bundled with Playwright Test:
- Playwright Inspector
- Playwright Test Code generation
- Playwright Tracing for post-mortem debugging
Further Reading
Learn more about Playwright Test runner: