Write Unit Test For With NestJS 2023

By XiaoXin
A Bit Randomly

Use a responsive image formatUse a next-generation image formatCompress imagesUse a CDNImage optimization is a technique that involves reducing the file size of images without compromising their quality, in order to improv... Read 4 Ways To Image Optimization On Website

Main Contents

Write Unit Test For With NestJS

To write unit tests for a NestJS application, you will need to use a testing framework such as Jest or Mocha. In this example, we will use Jest.

First, you will need to install Jest as a dev dependency in your project:

npm install --save-dev jest

Next, you will need to create a test file for your unit test. Test files should be placed in a __tests__ directory within your project, or you can use the .spec.ts or .test.ts file extension.

Here's an example of a simple unit test for a NestJS service:

import { Test } from '@nestjs/testing';
import { MyService } from './my.service';

describe('MyService', () => {
  let service: MyService;

  beforeEach(async () => {
    const module = await Test.createTestingModule({
      providers: [MyService],

    service = module.get<MyService>(MyService);

  it('should be defined', () => {

  it('should return "Hello, world!"', () => {
    expect(service.sayHello()).toEqual('Hello, world!');

In this example, we are using the Test class from @nestjs/testing to create a testing module that includes the MyService provider. We then use the module.get method to retrieve an instance of the service, which we can use to run our tests.

To run your unit tests, you can use the npm test command. This will execute all of the tests in your project and report the results.

Please Share This Article Thank You!

NodeJS Error Handling Simple Practices

Here is an example of using a try-catch block in Node.js: try { // code that may throw an error const result = someFunction(); console.log(result); } catch (error) { // handle the error console.error(error); } In this exam...

Why You Should Learn NestJS?

There are several reasons why learning NestJS can be beneficial for a developer: NestJS is built on top of Express, a popular and well-documented Node.js framework. This means that you can leverage your knowledge of Expres...