@testgen/ai

AI-powered unit test generator - zero config, works with all AI IDEs

Generate comprehensive unit tests using AI assistants (Cursor, VS Code + Copilot, JetBrains, etc.) with framework-specific prompts for Jest, xUnit, NUnit, and more.

Quick Start (2 Minutes)

# Install
npm install -D @testgen/ai

# Initialize (auto-detects everything)
npx testgen-init

# Done! Start using prompts in your AI IDE

Features

• ✅ Zero Configuration: Works out of the box with smart defaults
• ✅ Lightweight: < 5MB package size
• ✅ Universal: Works with all AI IDEs (Cursor, VS Code + Copilot, JetBrains, Codeium, etc.)
• ✅ Auto-Detection: Automatically detects project type and testing framework
• ✅ Multi-Framework: Supports Jest, xUnit, NUnit, Vitest, Mocha, Jasmine
• ✅ Detailed Prompts: Framework-specific prompts with best practices and examples
• ✅ Smart Defaults: No config file needed unless you want customization

Installation

npm install -D @testgen/ai
npx testgen-init

That's it! The package will:

• Auto-detect your project type (React, Node.js, .NET, etc.)
• Auto-detect your testing framework (Jest, xUnit, NUnit, etc.)
• Create test directories
• Configure everything automatically

Usage with AI IDEs

Universal Prompt Format

Works identically in all AI IDEs (Cursor, VS Code + Copilot, JetBrains AI, Codeium, etc.):

Using @testgen/ai prompts, generate unit tests for ComponentName

Using the Jest + React test generation prompt from @testgen/ai, generate unit tests for:
- Component: UserProfile
- Source File: src/components/UserProfile.tsx
- Test scenarios: Component renders, handles user interactions, displays errors

Example: Jest + React Tests

Using @testgen/ai Jest + React prompt, generate unit tests for:
- Component: UserProfile
- Source File: src/components/UserProfile.tsx
- Test scenarios: 
  - Component renders with user data
  - Component handles edit button click
  - Component displays error message on API failure

Example: Jest + Node.js Tests

Using @testgen/ai Jest Node.js prompt, generate unit tests for:
- Function: calculateTotal
- Source File: src/utils/calculator.ts
- Test scenarios:
  - Function calculates total correctly
  - Function handles empty array
  - Function throws error for invalid input

Example: xUnit .NET Tests

Using @testgen/ai xUnit .NET prompt, generate unit tests for:
- Class: UserService
- Source File: Services/UserService.cs
- Test scenarios:
  - GetUserById returns user for valid ID
  - GetUserById throws NotFoundException for invalid ID
  - CreateUser creates user successfully

CLI Commands

# Initialize (one-time setup)
npx testgen-init

# Generate test prompts
npx testgen-generate jest-react    # Show Jest + React prompt
npx testgen-generate jest-node     # Show Jest Node.js prompt
npx testgen-generate xunit         # Show xUnit .NET prompt
npx testgen-generate               # Auto-detect and show prompt

# Run tests (helper command)
npx testgen-run                    # Shows how to run tests

Supported Frameworks

Primary Support

• ✅ Jest - React components and Node.js functions
• ✅ xUnit - .NET classes and methods

Extended Support

• ✅ NUnit - .NET testing
• ✅ Vitest - Fast Vite-native unit testing
• ✅ Mocha - Flexible JavaScript testing
• ✅ Jasmine - Behavior-driven JavaScript testing

Project Detection

The package automatically detects:

• Project Type: React, Vue, Angular, .NET, Node.js
• Testing Framework: Jest, Vitest, xUnit, NUnit, Mocha, Jasmine
• Test Directory: __tests__, tests, Tests, etc.
• IDE: Cursor, VS Code, JetBrains, Codeium

Configuration (Optional)

The package works with zero configuration. A config file is only needed for customization:

// testgen.config.js (optional)
export default {
  projectType: 'react',
  testingFramework: 'jest',
  testDirectory: './__tests__',
  sourceDirectory: './src',
};

IDE Support

Cursor

• Auto-detected
• Prompts work immediately
• No configuration needed

VS Code + GitHub Copilot

• Auto-detected
• Use prompts in Copilot Chat
• No configuration needed

JetBrains AI

• Auto-detected
• Use prompts in AI Assistant
• No configuration needed

Codeium

• Uses VS Code configuration
• Works with Codeium extension
• No configuration needed

Any Other AI IDE

• Prompts work universally
• Copy prompts from npx testgen-generate
• No configuration needed

Available Prompts

Prompts are located in prompts/universal/:

• jest-react.md - Jest + React Testing Library
• jest-node.md - Jest for Node.js
• xunit-dotnet.md - xUnit for .NET
• nunit-dotnet.md - NUnit for .NET
• vitest.md - Vitest
• README.md - Usage documentation

Requirements

• Node.js 20+
• TypeScript (optional, peer dependency)
• Testing framework installed in your project (Jest, xUnit, etc.)

How It Works

1. Install the package: npm install -D @testgen/ai
2. Initialize: npx testgen-init (auto-detects everything)
3. Use Prompts: Reference prompts in your AI IDE
4. Generate Tests: AI generates comprehensive unit tests
5. Run Tests: Use your framework's test runner

Examples

React Component Test

// Generated by AI using @testgen/ai prompts
import { render, screen, fireEvent } from '@testing-library/react';
import userEvent from '@testing-library/user-event';
import { UserProfile } from './UserProfile';

describe('UserProfile', () => {
  test('should render with user data', () => {
    render(<UserProfile user={{ name: 'John', email: '[email protected]' }} />);
    expect(screen.getByText('John')).toBeInTheDocument();
  });

  test('should handle edit button click', async () => {
    const user = userEvent.setup();
    render(<UserProfile user={{ name: 'John' }} />);
    
    const editButton = screen.getByRole('button', { name: /edit/i });
    await user.click(editButton);
    
    expect(screen.getByRole('textbox')).toBeInTheDocument();
  });
});

.NET xUnit Test

// Generated by AI using @testgen/ai prompts
using Xunit;
using Moq;

namespace Tests
{
    public class UserServiceTests
    {
        private readonly Mock<IUserRepository> _mockRepository;
        private readonly UserService _sut;

        public UserServiceTests()
        {
            _mockRepository = new Mock<IUserRepository>();
            _sut = new UserService(_mockRepository.Object);
        }

        [Fact]
        public void GetUserById_WithValidId_Should_ReturnUser()
        {
            // Arrange
            var userId = 1;
            var expectedUser = new User { Id = userId, Name = "John" };
            _mockRepository.Setup(x => x.GetById(userId)).Returns(expectedUser);
            
            // Act
            var result = _sut.GetUserById(userId);
            
            // Assert
            Assert.Equal(expectedUser, result);
        }
    }
}

License

MIT

Support

• Documentation: See prompts/universal/README.md for prompt usage
• Issues: GitHub Issues
• IDE Setup: See USAGE.md for detailed usage guide