---
title: "GitHub Copilot Testing Jest"
description: "Comprehensive testing setup with Jest, React Testing Library, and E2E automation using Cypress and Playwright."
category: "configuration"
tags: ["github-copilot", "testing", "jest", "react-testing-library", "e2e", "tdd"]
tech_stack: ["jest", "react-testing-library", "cypress", "playwright", "testing-library"]
---

This configuration sets you up with a solid testing framework using Jest for unit tests, React Testing Library for component tests, and Cypress along with Playwright for end-to-end automation.

### Configuration Overview
This setup allows for streamlined testing practices, covering unit tests, component tests, and end-to-end tests. This approach helps maintain high code quality and reliability.

### Prerequisites
Before you start, make sure you have the following:
- **Node.js** (version 14 or higher)
- **npm** (version 6 or higher)
- **GitHub Copilot** enabled in your IDE
- **Cypress** and **Playwright** installed either globally or locally in your project

### Installation & Setup
Let's get your project up and running:

1. **Initialize your project**:
   ```bash
   mkdir my-testing-app
   cd my-testing-app
   npm init -y
   ```
2. **Install dependencies**:
   ```bash
   npm install --save-dev jest @testing-library/react @testing-library/jest-dom cypress playwright
   ```
3. **Configure Jest**:
   Create a file called `jest.config.js` and add the following:
   ```javascript
   module.exports = {
     testEnvironment: "jsdom",
     setupFilesAfterEnv: ["<rootDir>/setupTests.js"],
     collectCoverage: true,
     coverageReporters: ["text", "lcov"],
   };
   ```
4. **Set up testing utilities**:
   Create a file named `setupTests.js` with this content:
   ```javascript
   import '@testing-library/jest-dom/extend-expect';
   ```
5. **Configure Cypress**:
   Start Cypress by running:
   ```bash
   npx cypress open
   ```
   This command generates a `cypress` folder with the default structure. You can customize `cypress.json` as follows:
   ```json
   {
     "baseUrl": "http://localhost:3000",
     "integrationFolder": "cypress/integration",
     "supportFile": "cypress/support/index.js"
   }
   ```
6. **Configure Playwright**:
   Initialize Playwright using:
   ```bash
   npx playwright install
   ```
   Then, create a basic test in `tests/example.spec.js`:
   ```javascript
   const { test, expect } = require('@playwright/test');

   test('homepage has title', async ({ page }) => {
     await page.goto('http://localhost:3000');
     await expect(page).toHaveTitle(/Home/);
   });
   ```

### File Structure
Here’s how your project will look:
```
my-testing-app/
├── cypress/
│   ├── fixtures/
│   ├── integration/
│   ├── plugins/
│   └── support/
├── tests/
│   └── example.spec.js
├── node_modules/
├── package.json
├── jest.config.js
└── setupTests.js
```

### Key Configuration Files
- **`jest.config.js`**: This file gets Jest ready to use jsdom and sets up coverage reporting.
- **`setupTests.js`**: This imports the necessary matchers for testing with React Testing Library.
- **`cypress.json`**: This file contains the base URL and folder structure for Cypress tests.

### Advanced Options
Here are a few advanced features to consider:
- **Jest Performance Tuning**: Run tests sequentially in CI environments using `--runInBand`.
- **Cypress Parallelization**: Leverage the Cypress Dashboard to run tests in parallel, speeding up feedback.
- **Playwright Browser Contexts**: Create multiple browser contexts for isolated tests.

### Troubleshooting
If you run into issues, here are some quick fixes:
- **Jest not recognizing tests**: Check that your test files follow the naming convention (e.g., `*.test.js`).
- **Cypress not launching**: Verify that the base URL is correct in `cypress.json`.
- **Playwright tests failing**: Make sure your server is running before testing.

### Best Practices
Keep these tips in mind for effective testing:
- **Write tests alongside features**: Embrace test-driven development (TDD) to boost code quality.
- **Use snapshots wisely**: Apply them only to stable components that don’t change often.
- **Keep tests isolated**: Avoid shared state among tests to reduce flaky results.

### Performance Tuning and Workflow Optimization Tips
To optimize your workflow, try these strategies:
- **Run tests in watch mode**: Use `npm test -- --watch` for immediate feedback during development.
- **Group related tests**: Organize tests logically to enhance maintainability and readability.
- **Utilize CI/CD**: Integrate testing into your CI/CD pipeline for automatic testing with each commit.