Why E2E testing with Playwright in NextJS? - Purpose & Use Cases

The Big Idea

What if your website could test itself every time you change it?

The Scenario

Imagine you have a website with many pages and features. You open each page in your browser, click buttons, fill forms, and check if everything works as expected. You do this every time you make a change to your code.

The Problem

This manual checking takes a lot of time and is easy to forget or miss small problems. Sometimes you click the wrong button or forget to test some pages. It becomes tiring and slows down your work.

The Solution

End-to-end (E2E) testing with Playwright lets you write scripts that automatically open your website, click buttons, fill forms, and check results just like a real user. It runs tests fast and exactly the same way every time, so you catch problems early.

Before vs After

✗ Before

Open browser
Click button
Check page
Repeat for each feature

✓ After

await page.goto('https://example.com');
await page.click('button#submit');
expect(await page.textContent('h1')).toBe('Welcome');

What It Enables

It makes testing fast, reliable, and repeatable, so you can confidently improve your website without breaking anything.

Real Life Example

A developer changes the login page code. Instead of manually testing login every time, Playwright runs the login test automatically and alerts if something breaks.

Key Takeaways

Manual testing is slow and error-prone.

Playwright automates user actions and checks results.

Automated E2E tests save time and catch bugs early.