Next.js 15 Fullstack Web Apps · 강의

Playwright를 사용한 종단 간 테스트

전체 애플리케이션 흐름에서 사용자 상호 작용을 시뮬레이션하도록 종단 간 테스트를 설정합니다.

Playwright를 사용한 종단 간 테스트은(는) CoddyKit의 무료 Next.js 15 Fullstack Web Apps 강의입니다. 이것은 4개 중 2번째 강의입니다. 아래에서 전체 강의를 무료로 읽을 수 있으며, 내장 코드 에디터와 24/7 AI 튜터와 함께 브라우저에서 직접 실습할 수 있습니다. 이 강의는 Next.js 15 Fullstack Web Apps 학습 경로의 일부이며, 진행 상황이 웹과 CoddyKit 앱에 동기화됩니다. Next.js 15 Fullstack Web Apps 강의에는 총 4개의 강의가 포함되어 있습니다.

이 강의의 일부는 아직 번역되지 않았으며 영어로 표시됩니다.

What is End-to-End Testing?

End-to-End (E2E) testing simulates a real user's journey through your application, from start to finish. It tests the entire stack: frontend, backend, and database.

Think of it as a robot user interacting with your app in a browser. This ensures all parts of your system work together as expected, catching issues that unit or integration tests might miss.

Why Playwright for E2E?

Playwright is a powerful open-source tool by Microsoft designed for reliable E2E testing. It offers several key advantages:

Cross-browser: Tests Chromium, Firefox, and WebKit (Safari).
Auto-wait: Automatically waits for elements to be ready, reducing flakiness.
Robust actions: Simulates real user interactions like clicks, fills, and key presses.
Fast & parallel: Can run tests across multiple browsers simultaneously.

Setting Up Playwright

To get started, you'll need to install Playwright in your Next.js project. This command sets up Playwright and downloads necessary browser binaries:

npm init playwright@latest

This will guide you through setting up a basic configuration file (playwright.config.ts) and an example test. Remember to have your Next.js application running (e.g., npm run dev) when running E2E tests!

Your First Playwright Test

Let's write a simple test to navigate to a page and check its title. Playwright tests are typically written in JavaScript or TypeScript.

This example assumes your Next.js app is running on http://localhost:3000.

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

test('homepage has expected title', async ({ page }) => {
  await page.goto('http://localhost:3000/');
  // Check if the page title contains 'Next.js App'
  await expect(page).toHaveTitle(/Next.js App/);
});

Interacting with Elements

Playwright provides powerful locators to find elements on the page. You can interact with these elements by filling input fields, clicking buttons, and more.

Common locators include getByRole(), getByText(), getByLabel(), and locator() for CSS selectors.

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

test('fill and submit a contact form', async ({ page }) => {
  await page.goto('http://localhost:3000/contact');

  // Fill input fields by label or placeholder
  await page.getByLabel('Your Name').fill('Alice');
  await page.getByPlaceholder('email@example.com').fill('alice@example.com');

  // Click the submit button
  await page.getByRole('button', { name: 'Send Message' }).click();

  // Assert that a success message appears
  await expect(page.getByText('Message sent successfully!')).toBeVisible();
});

Assertions and Auto-Waiting

Playwright's expect API is used to make assertions about the state of your application. A key feature is auto-waiting, where Playwright automatically waits for elements to become visible, enabled, or stable before performing an action or assertion.

This significantly reduces the need for manual waits, making your tests more robust and less prone to flakiness.

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

test('check item count', async ({ page }) => {
  await page.goto('http://localhost:3000/products');

  // Playwright waits for the list to render
  const productList = page.locator('.product-item');
  await expect(productList).toHaveCount(5);

  // Click a filter button
  await page.getByRole('button', { name: 'Filter by Category A' }).click();

  // Playwright waits for the list to update after filtering
  await expect(productList).toHaveCount(2);
});

Testing a Full User Flow

Let's simulate a more complex user journey: a user logging in, navigating to a dashboard, and verifying content. This demonstrates how E2E tests cover multiple pages and interactions.

Ensure your Next.js application has a login page and a dashboard for this test to pass.

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

test('user can log in and view dashboard', async ({ page }) => {
  await page.goto('http://localhost:3000/login');

  // Fill login form
  await page.getByLabel('Username').fill('testuser');
  await page.getByLabel('Password').fill('securepassword');
  await page.getByRole('button', { name: 'Log In' }).click();

  // Wait for navigation to the dashboard and verify content
  await page.waitForURL('http://localhost:3000/dashboard');
  await expect(page.getByRole('heading', { name: 'Welcome, testuser!' })).toBeVisible();
  await expect(page.getByText('Your recent activity')).toBeVisible();
});

Running Tests & Reporting

After writing your tests, you can run them from your terminal. Playwright provides a powerful test runner and various reporting options:

Run all tests: npx playwright test
Run specific test file: npx playwright test example.spec.js
Run tests in headed mode (browser visible): npx playwright test --headed
HTML Reporter: After tests run, open playwright-report/index.html for a detailed, interactive report.

Best Practices for E2E Tests

To write effective and maintainable E2E tests:

Target user-facing elements: Use locators that reflect how a user sees the page (e.g., getByRole, getByText).
Use data-testid attributes: For elements without clear text or roles, add data-testid attributes for robust selection.
Keep tests independent: Each test should set up its own state and not rely on previous tests.
Balance test types: E2E tests are slower; use them for critical user flows, and rely on unit/integration tests for smaller components.

Playwright Test Concepts

Which of the following are key benefits or features of Playwright for End-to-End testing?

Recap: E2E with Playwright

We've explored End-to-End testing and how Playwright helps you simulate real user interactions across your entire Next.js application.

You learned to set up Playwright, write tests that navigate, interact with elements, and assert outcomes. With its auto-waiting capabilities and cross-browser support, Playwright is a powerful tool for ensuring the reliability of your fullstack applications.

자주 묻는 질문

“Playwright를 사용한 종단 간 테스트” 강의는 무료인가요?

네 — “Playwright를 사용한 종단 간 테스트” 전체 내용을 이 웹사이트에서 무료로 읽을 수 있습니다. 인터랙티브하게 실습하려면(내장 코드 에디터와 24/7 AI 튜터), CoddyKit PRO로 업그레이드하면 Next.js 15 Fullstack Web Apps 강의 전체를 잠금 해제할 수 있습니다. Next.js 15 Fullstack Web Apps 강의에는 총 4개의 강의가 포함되어 있습니다.

“Playwright를 사용한 종단 간 테스트”에서 뭘 배우나요?

전체 애플리케이션 흐름에서 사용자 상호 작용을 시뮬레이션하도록 종단 간 테스트를 설정합니다. 브라우저에서 직접 실행하는 실습 코드로 Next.js 15 Fullstack Web Apps을(를) 배우며, 24/7 AI 튜터가 강의를 진행하면서 질문에 답변해줍니다.

Next.js 15 Fullstack Web Apps을(를) 시작하는 데 경험이 필요한가요?

사전 경험은 필요하지 않습니다. CoddyKit의 Next.js 15 Fullstack Web Apps은(는) 초급자부터 고급 학습자까지를 위해 구성되어 있으므로, 여기서 시작하거나 처음부터 시작할 수 있으며 자신의 속도대로 진행할 수 있습니다. 이것은 4개 중 2번째 강의입니다.

“Playwright를 사용한 종단 간 테스트” 강의는 얼마나 걸리나요?

대부분의 CoddyKit 강의는 약 5~10분이 소요됩니다. 각 강의는 간결하고 인터랙티브하여 꾸준한 진행이 가능하며, 웹과 앱에서 중단한 부분부터 바로 시작할 수 있습니다.

이 Next.js 15 Fullstack Web Apps 강의에서 코드를 작성하고 실행할 수 있나요?

네. 모든 Next.js 15 Fullstack Web Apps 강의에는 내장 코드 에디터가 포함되어 있으므로, 브라우저에서 바로 실제 코드를 작성하고 실행한 후 즉시 AI 피드백을 받을 수 있습니다 — 로컬 설정이 필요 없습니다.

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