E2e Testing Expert

E2E Testing Expert (Playwright 1.49+ / Vitest 3 Edition)

English | Bahasa Indonesia

English

Orchestration & Integration

Connects and orchestrates with relevant domain skills like brainstorming, zero-to-prod-orchestrator, and project-context-mapper to ensure cohesive execution.

Description

Expert guide for building comprehensive automated test suites using Playwright 1.49+ (E2E + component testing), Vitest 3 (unit/integration), and robust CI/CD pipelines. Covers modern testing patterns for Next.js 15, React 19, and API backends.

Trigger Conditions

• Writing E2E tests for web applications with Playwright.
• Writing unit or integration tests with Vitest.
• Setting up a full automated testing pipeline in GitHub Actions / GitLab CI.
• Testing React components in isolation with Playwright Component Testing.
• Mocking external services (APIs, databases) in tests.
• Setting up visual regression tests.

Playwright 1.49+ — Key Updates

New in 2026

• aria-snapshot: Assert the accessibility tree as a snapshot — more semantic than DOM snapshots.
• page.addLocatorHandler(): Handle dynamic UI (modals, cookie banners) automatically.
• WebSocket testing: Built-in page.expectWebSocketEvent().
• Playwright MCP Server: Expose a Playwright browser to AI agents via MCP tools.

Project Configuration

// playwright.config.ts
import { defineConfig, devices } from '@playwright/test';

export default defineConfig({
  testDir: './tests/e2e',
  fullyParallel: true,
  forbidOnly: !!process.env.CI,
  retries: process.env.CI ? 2 : 0,
  workers: process.env.CI ? 4 : undefined,
  reporter: [
    ['html', { open: 'never' }],
    ['junit', { outputFile: 'results.xml' }],
  ],
  use: {
    baseURL: process.env.PLAYWRIGHT_BASE_URL ?? 'http://localhost:3000',
    trace: 'on-first-retry',
    screenshot: 'only-on-failure',
    video: 'on-first-retry',
  },
  projects: [
    // Setup: seed test DB
    { name: 'setup', testMatch: /.*\.setup\.ts/ },
    {
      name: 'chromium',
      use: { ...devices['Desktop Chrome'] },
      dependencies: ['setup'],
    },
    {
      name: 'mobile-chrome',
      use: { ...devices['Pixel 7'] },
      dependencies: ['setup'],
    },
  ],
  webServer: {
    command: 'npm run dev',
    url: 'http://localhost:3000',
    reuseExistingServer: !process.env.CI,
  },
});

Page Object Model (POM)

// tests/e2e/pages/LoginPage.ts
import { type Page, type Locator, expect } from '@playwright/test';

export class LoginPage {
  readonly page: Page;
  readonly emailInput: Locator;
  readonly passwordInput: Locator;
  readonly submitButton: Locator;

  constructor(page: Page) {
    this.page = page;
    this.emailInput = page.getByLabel('Email');
    this.passwordInput = page.getByLabel('Password');
    this.submitButton = page.getByRole('button', { name: 'Sign in' });
  }

  async goto() {
    await this.page.goto('/login');
  }

  async login(email: string, password: string) {
    await this.emailInput.fill(email);
    await this.passwordInput.fill(password);
    await this.submitButton.click();
    await this.page.waitForURL('/dashboard');
  }
}

API Mocking with page.route()

test('shows error when API fails', async ({ page }) => {
  // Intercept and mock API response
  await page.route('**/api/users', (route) => {
    route.fulfill({
      status: 500,
      body: JSON.stringify({ error: 'Internal server error' }),
      contentType: 'application/json',
    });
  });

  await page.goto('/users');
  await expect(page.getByRole('alert')).toContainText('Something went wrong');
});

Accessibility Assertions (aria-snapshot)

test('navigation is accessible', async ({ page }) => {
  await page.goto('/');
  
  // Assert accessibility tree structure
  await expect(page.locator('nav')).toMatchAriaSnapshot(`
    - navigation:
      - link "Home"
      - link "Products"
      - link "Pricing"
      - link "Sign in"
  `);
});

Auth State Reuse (storageState)

// tests/e2e/auth.setup.ts
import { test as setup } from '@playwright/test';

setup('authenticate', async ({ page }) => {
  await page.goto('/login');
  await page.getByLabel('Email').fill('test@example.com');
  await page.getByLabel('Password').fill('password');
  await page.getByRole('button', { name: 'Sign in' }).click();
  await page.waitForURL('/dashboard');
  
  // Save session state for reuse in all tests
  await page.context().storageState({ path: 'playwright/.auth/user.json' });
});

// tests/e2e/dashboard.spec.ts
import { test } from '@playwright/test';

test.use({ storageState: 'playwright/.auth/user.json' });

test('dashboard loads correctly', async ({ page }) => {
  await page.goto('/dashboard');
  // Already authenticated — no login needed
});

Vitest 3 — Unit & Integration Testing

Configuration

// vitest.config.ts
import { defineConfig } from 'vitest/config';
import react from '@vitejs/plugin-react';

export default defineConfig({
  plugins: [react()],
  test: {
    environment: 'jsdom',
    globals: true,
    setupFiles: ['./tests/setup.ts'],
    coverage: {
      provider: 'v8',
      reporter: ['text', 'lcov', 'html'],
      thresholds: { lines: 80, functions: 80 },
    },
  },
});

React Component Testing

import { render, screen, userEvent } from '@testing-library/react';
import { describe, it, expect, vi } from 'vitest';
import { Counter } from './Counter';

describe('Counter', () => {
  it('increments count on button click', async () => {
    const user = userEvent.setup();
    render(<Counter initialCount={0} />);

    await user.click(screen.getByRole('button', { name: 'Increment' }));

    expect(screen.getByText('Count: 1')).toBeInTheDocument();
  });

  it('calls onMaxReached when limit hit', async () => {
    const
    const user = userEvent.setup();
    render(<Counter initialCount={9} max={10} />);

    await user.click(screen.getByRole('button', { name: 'Increment' }));

    expect(onMaxReached).toHaveBeenCalledOnce();
  });
});

Server Action / API Route Testing

import { describe, it, expect, beforeEach } from 'vitest';
import { testClient } from 'hono/testing';
import { app } from '../src/server';
import { resetTestDb } from './helpers/db';

describe('POST /api/users', () => {
  beforeEach(resetTestDb);

  it('creates a new user', async () => {
    const client = testClient(app);
    const res = await client.api.users.$post({
      json: { name: 'Alice', email: 'alice@example.com' },
    });

    expect(res.status).toBe(201);
    const data = await res.json();
    expect(data.email).toBe('alice@example.com');
  });
});

GitHub Actions CI Pipeline

# .github/workflows/test.yml
name: CI Tests

on: [push, pull_request]

jobs:
  unit:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-node@v4
        with: { node-version: '22', cache: 'pnpm' }
      - run: pnpm install --frozen-lockfile
      - run: pnpm run typecheck
      - run: pnpm run test:unit --coverage

  e2e:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-node@v4
        with: { node-version: '22', cache: 'pnpm' }
      - run: pnpm install --frozen-lockfile
      - run: pnpm exec playwright install --with-deps chromium
      - run: pnpm run test:e2e
      - uses: actions/upload-artifact@v4
        if: failure()
        with:
          name: playwright-report
          path: playwright-report/

Bahasa Indonesia

Integrasi Orkestrasi

Terhubung dan mengorkestrasi skill domain yang relevan seperti brainstorming, zero-to-prod-orchestrator, dan project-context-mapper untuk memastikan eksekusi yang kohesif.

Deskripsi

Panduan ahli untuk membangun test suite otomatis yang komprehensif menggunakan Playwright 1.49+ (E2E + component testing), Vitest 3 (unit/integrasi), dan pipeline CI/CD yang kuat. Mencakup pola pengujian modern untuk Next.js 15, React 19, dan backend API.

Kondisi Pemicu

• Menulis E2E test untuk aplikasi web dengan Playwright.
• Menulis unit atau integration test dengan Vitest.
• Menyiapkan pipeline pengujian otomatis di GitHub Actions / GitLab CI.
• Menguji komponen React secara terisolasi.
• Mocking layanan eksternal (API, database) dalam test.
• Menyiapkan visual regression test.

Playwright 1.49+ — Fitur Baru 2026

• aria-snapshot: Assert accessibility tree sebagai snapshot.
• page.addLocatorHandler(): Tangani UI dinamis (modal, cookie banner) secara otomatis.
• WebSocket testing: page.expectWebSocketEvent() bawaan.
• Playwright MCP Server: Ekspos browser Playwright ke agen AI via MCP.

Page Object Model (POM)

Enkapsulasi selektor dan tindakan halaman dalam kelas terpisah untuk mengurangi duplikasi dan meningkatkan keterbacaan test.

Mocking API dengan page.route()

Gunakan page.route() untuk mencegat permintaan jaringan dan mengembalikan respons palsu — mengisolasi frontend dari backend dalam E2E test.

Aksesibilitas dengan aria-snapshot

Gunakan toMatchAriaSnapshot() untuk memvalidasi struktur aksesibilitas navigasi, form, dan komponen interaktif — lebih semantis dari snapshot DOM biasa.

Auth State Reuse (storageState)

Gunakan storageState untuk menyimpan state sesi setelah login sekali dan menggunakannya kembali di semua test yang memerlukan autentikasi — menghemat waktu secara signifikan.

Vitest 3 — Unit & Integration Testing

Vitest 3 adalah test runner yang cepat berbasis Vite dengan kompatibilitas Jest penuh. Gunakan untuk unit test React component, server action, dan logika bisnis.

Pipeline CI GitHub Actions

Pisahkan job unit dan e2e untuk feedback paralel yang lebih cepat. Upload playwright-report sebagai artifact saat gagal untuk debugging.