How do I avoid conflicts between Jest and Playwright tests in a TypeScript and Next.js application?

Answer

To avoid conflicts between Jest and Playwright tests in your TypeScript and Next.js app, you can create separate tsconfig.json files for each test suite. For example, add a tsconfig.json file inside the tests directory specifically for running Playwright tests. This allows you to set preferences for each test suite independently.

{
  "extends": "../tsconfig.json",
  "compilerOptions": {
    "types": ["@playwright/test"]
  }
}

Keep your dependencies up-to-date, especially Playwright, to ensure compatibility with the latest browser versions. This helps you catch failures before they reach users.

Set up CI/CD and run tests frequently, ideally on each commit and pull request. Playwright includes a GitHub Actions workflow for easy CI integration.

Optimize performance by using parallelism and sharding when running Playwright tests. By default, Playwright runs tests in parallel. However, if you have many independent tests in a single file, consider configuring them explicitly as parallel using test.describe.configure({ mode: 'parallel' });.

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

test.describe.configure({ mode: 'parallel' })('My parallel tests', () => {
  test('Test 1', async ({ page }) => {
    await page.goto('https://ray.run/');
    // Your test code here
  });

  test('Test 2', async ({ page }) => {
    await page.goto('https://ray.run/');
    // Your test code here
  });
});

By following these best practices, you can prevent Jest and Playwright tests from clashing in your TypeScript and Next.js app.