playwright

Playwright Best Practices

Overview

Aspect	Recommendation
Pattern	Page Object Model
Assertions	Web-first assertions
Selectors	Test IDs or role-based
Parallel	Run tests in parallel

---

Configuration

playwright.config.ts

import { defineConfig, devices } from '@playwright/test'

export default defineConfig({
  testDir: './e2e',
  fullyParallel: true,
  forbidOnly: !!process.env.CI,
  retries: process.env.CI ? 2 : 0,
  workers: process.env.CI ? 1 : undefined,
  reporter: 'html',
  use: {
    baseURL: 'http://localhost:3000',
    trace: 'on-first-retry',
    screenshot: 'only-on-failure',
  },
  projects: [
    {
      name: 'chromium',
      use: { ...devices['Desktop Chrome'] },
    },
    {
      name: 'firefox',
      use: { ...devices['Desktop Firefox'] },
    },
    {
      name: 'webkit',
      use: { ...devices['Desktop Safari'] },
    },
    {
      name: 'Mobile Chrome',
      use: { ...devices['Pixel 5'] },
    },
  ],
  webServer: {
    command: 'npm run dev',
    url: 'http://localhost:3000',
    reuseExistingServer: !process.env.CI,
  },
})

---

Basic Tests

First Test

import { test, expect } from '@playwright/test'

test('homepage has title', async ({ page }) => {
  await page.goto('/')
  
  await expect(page).toHaveTitle(/My App/)
})

test('navigation works', async ({ page }) => {
  await page.goto('/')
  
  await page.getByRole('link', { name: 'About' }).click()
  
  await expect(page).toHaveURL('/about')
  await expect(page.getByRole('heading', { name: 'About Us' })).toBeVisible()
})

---

Selectors

Recommended (Role-based)

// ✅ Best - Role-based selectors
await page.getByRole('button', { name: 'Submit' }).click()
await page.getByRole('textbox', { name: 'Email' }).fill('[email protected]')
await page.getByRole('link', { name: 'Home' }).click()
await page.getByRole('heading', { level: 1 }).toBeVisible()

// ✅ Good - Test IDs
await page.getByTestId('submit-button').click()

// ✅ Good - Labels and placeholders
await page.getByLabel('Email').fill('[email protected]')
await page.getByPlaceholder('Search...').fill('query')
await page.getByText('Welcome back').toBeVisible()