What is @nestjs/testing?
The @nestjs/testing package provides a set of utilities designed to help with the testing of NestJS applications. It simplifies the process of setting up a testing environment, allowing developers to focus on writing their tests. This package is specifically tailored for NestJS, making it easier to test modules, services, controllers, and other components within a NestJS application.
What are @nestjs/testing's main functionalities?
Unit Testing Controllers
This example demonstrates how to set up a unit test for a controller in NestJS using the @nestjs/testing package. It shows the creation of a testing module, mocking dependencies, and asserting the controller's existence.
import { Test, TestingModule } from '@nestjs/testing';
import { CatsController } from './cats.controller';
import { CatsService } from './cats.service';
describe('CatsController', () => {
let controller: CatsController;
beforeEach(async () => {
const module: TestingModule = await Test.createTestingModule({
controllers: [CatsController],
providers: [{ provide: CatsService, useValue: {} }],
}).compile();
controller = module.get<CatsController>(CatsController);
});
it('should be defined', () => {
expect(controller).toBeDefined();
});
});
Integration Testing
This code snippet illustrates how to perform an integration test on a NestJS application. It involves setting up the entire application within the test environment and using the 'supertest' package to make HTTP requests to test the application's endpoints.
import { Test, TestingModule } from '@nestjs/testing';
import { INestApplication } from '@nestjs/common';
import * as request from 'supertest';
import { AppModule } from './../src/app.module';
describe('Cats', () => {
let app: INestApplication;
beforeAll(async () => {
const moduleFixture: TestingModule = await Test.createTestingModule({
imports: [AppModule],
}).compile();
app = moduleFixture.createNestApplication();
await app.init();
});
it('/GET cats', () => {
return request(app.getHttpServer())
.get('/cats')
.expect(200)
.expect('This action returns all cats');
});
});
Other packages similar to @nestjs/testing
jest
Jest is a delightful JavaScript Testing Framework with a focus on simplicity. It works with projects using: Babel, TypeScript, Node, React, Angular, Vue, and more. Jest is often used in combination with NestJS for unit and integration testing, similar to @nestjs/testing, but it is more general-purpose and not specifically tailored to NestJS.
mocha
Mocha is a feature-rich JavaScript test framework running on Node.js and in the browser, making asynchronous testing simple and fun. Mocha tests run serially, allowing for flexible and accurate reporting, while mapping uncaught exceptions to the correct test cases. It is another alternative to @nestjs/testing for writing tests in a NestJS application, but it requires more setup and configuration to integrate smoothly with NestJS.
chai
Chai is a BDD / TDD assertion library for node and the browser that can be delightfully paired with any javascript testing framework. It's often used alongside Mocha or Jest to provide more expressive assertions. While not a testing framework itself, it complements packages like @nestjs/testing by offering a rich set of assertions that can be used in tests.
A progressive Node.js framework for building efficient and scalable server-side applications.
Description
Nest is a framework for building efficient, scalable Node.js server-side applications. It uses modern JavaScript, is built with TypeScript (preserves compatibility with pure JavaScript) and combines elements of OOP (Object Oriented Programming), FP (Functional Programming), and FRP (Functional Reactive Programming).
Under the hood, Nest makes use of Express, but also provides compatibility with a wide range of other libraries, like Fastify, allowing for easy use of the myriad of third-party plugins which are available.
Philosophy
In recent years, thanks to Node.js, JavaScript has become the “lingua franca” of the web for both front and backend applications, giving rise to awesome projects like Angular, React, and Vue, which improve developer productivity and enable the construction of fast, testable, and extensible frontend applications. However, on the server-side, while there are a lot of superb libraries, helpers, and tools for Node, none of them effectively solve the main problem - the architecture.
Nest aims to provide an application architecture out of the box which allows for effortless creation of highly testable, scalable, and loosely coupled and easily maintainable applications. The architecture is heavily inspired by Angular.
Getting started
Questions
For questions and support please use the official Discord channel. The issue list of this repo is exclusively for bug reports and feature requests.
Issues
Please make sure to read the Issue Reporting Checklist before opening an issue. Issues not conforming to the guidelines may be closed immediately.
Consulting
With official support, you can get expert help straight from Nest core team. We provide dedicated technical support, migration strategies, advice on best practices (and design decisions), PR reviews, and team augmentation. Read more about support here.
Support
Nest is an MIT-licensed open source project. It can grow thanks to the sponsors and support from the amazing backers. If you'd like to join them, please read more here.
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License
Nest is MIT licensed.