Suites
A unit-testing framework for TypeScript backends using inversion of control and dependency injection
[](https://www.npmjs.com/package/@suites/unit)
[](https://www.npmjs.com/package/@suites/unit)
[](https://github.com/suites-dev/suites/blob/master/LICENSE)
[](https://www.typescriptlang.org/)
[Documentation](https://suites.dev/docs) • [GitHub](https://github.com/suites-dev/suites)
Testing classes with dependency injection usually means writing manual mocks for every constructor parameter. Change a dependency? Update every mock. Refactor a method? Hope your untyped mocks still work. Suites automates this away.
## What is Suites?
Suites is a **unit testing framework** that provides:
- **Declarative API** - Call `TestBed.solitary(YourClass)` and get a fully-typed test environment with mocks already generated and wired
- **Type-Safe Refactoring** - Add or remove constructor dependencies without touching your tests. TypeScript catches mismatches immediately
- **Framework Agnostic** - Write tests once, use the same pattern across NestJS services, InversifyJS modules, or plain TypeScript classes
- **AI Ready** - The consistent pattern makes it trivial for coding agents to generate correct tests without extensive context
Works with [NestJS](https://nestjs.com) (official), [InversifyJS](https://inversify.io) (official), [Jest](https://jestjs.io), [Vitest](https://vitest.dev), and [Sinon](https://sinonjs.org).
```typescript
import { TestBed, type Mocked } from '@suites/unit';
describe('UserService', () => {
let userService: UserService;
let userRepository: Mocked;
beforeAll(async () => {
const { unit, unitRef } = await TestBed.solitary(UserService).compile();
userService = unit;
userRepository = unitRef.get(UserRepository);
});
it('should return user name', async () => {
userRepository.getUserById.mockResolvedValue({ id: 1, name: 'John Doe' });
const result = await userService.getUserName(1);
expect(result).toBe('John Doe');
});
});
```
## Getting Started
**Fastest way to get started:**
[**5-Minute Quickstart Guide**](https://suites.dev/docs/get-started/quickstart)
**Explore comprehensive guides and examples:**
[View Documentation](https://suites.dev/docs) | [See Examples](https://github.com/suites-dev/suites/tree/master/examples) | [Learn Suites Patterns](https://suites.dev/docs/guides)
## Installation
```bash
npm i -D @suites/unit
```
You'll also need to install adapters for your DI framework and testing library. For example, NestJS with Jest:
```bash
npm i -D @suites/doubles.jest @suites/di.nestjs
```
[**Complete installation and setup guide**](https://suites.dev/docs/get-started/installation)
## Community
Join the Suites community on [GitHub Discussions](https://github.com/suites-dev/suites/discussions).
## Support
### Ask a question about Suites
[**Start a discussion**](https://github.com/suites-dev/suites/discussions/new?category=q-a)
### Create a bug report
[**Report a bug**](https://github.com/suites-dev/suites/issues/new?template=bug_report.md)
### Request a feature
[**Submit feature request**](https://github.com/suites-dev/suites/issues/new?template=feature_request.md)
## Contributing
We welcome contributions! See our [contribution guidelines](https://github.com/suites-dev/suites/blob/master/CONTRIBUTING.md) and [Code of Conduct](https://github.com/suites-dev/suites/blob/master/CODE_OF_CONDUCT.md).
## License
Distributed under the Apache (Apache-2.0) License. See `LICENSE` for more information.