Integration testing in NestJS - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is integration testing in NestJS?

Integration testing in NestJS checks how different parts of the application work together, like controllers, services, and modules, to ensure they interact correctly.

beginner

Which NestJS testing utility helps create a testing module for integration tests?

The Test.createTestingModule() method helps build a testing module that mimics the real module setup for integration testing.

intermediate

Why do we use beforeEach or beforeAll hooks in NestJS integration tests?

These hooks set up the testing environment before each or all tests run, like creating the testing module and initializing the app instance.

intermediate

How do you test HTTP endpoints in NestJS integration tests?

You use the supertest library to send HTTP requests to the NestJS app instance and check the responses to verify endpoint behavior.

beginner

What is the difference between unit testing and integration testing in NestJS?

Unit testing checks individual parts in isolation, while integration testing checks how multiple parts work together in the app.

Which method creates a testing module in NestJS integration tests?

A Module.forRoot()

B Test.createTestingModule()

C NestFactory.create()

D AppModule.init()

Test.createTestingModule() builds a testing module for integration tests.

What library is commonly used to test HTTP requests in NestJS integration tests?

A request-promise

B axios

C jest-fetch-mock

D supertest

supertest sends HTTP requests to the NestJS app during integration tests.

In NestJS, where do you usually initialize the app instance for integration testing?

A Inside the controller constructor

B Inside the main.ts file

C Inside beforeEach or beforeAll hooks

D Inside the service provider

beforeEach or beforeAll hooks set up the app instance before tests run.

Integration testing in NestJS mainly focuses on:

A Testing how modules and services work together

B Testing database schema only

C Testing UI components

D Testing individual functions only

Integration tests check interaction between modules and services.

Which of these is NOT a typical step in NestJS integration testing setup?

A Directly modifying production database

B Creating a testing module

C Using supertest to send HTTP requests

D Initializing the Nest app instance

Tests should avoid modifying the production database.

Explain how to set up a basic integration test in NestJS for an HTTP endpoint.

Think about how you prepare the app and send requests to test endpoints.

Describe the main difference between unit testing and integration testing in NestJS.

Focus on scope and interaction of tested parts.