Integration testing in NestJS - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to import the testing module for integration tests in NestJS.

NestJS

import { Test, TestingModule } from '@nestjs/[1]';

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Atesting

Btest

Ctests

Dtest-module

Attempts:

3 left

💡 Hint

Common Mistakes

Using '@nestjs/test' instead of '@nestjs/testing'

Misspelling the package name

The correct import for NestJS testing utilities is from '@nestjs/testing'.

2fill in blank

medium

Complete the code to create a testing module with the AppModule imported.

NestJS

const moduleRef: TestingModule = await Test.createTestingModule({ imports: [[1]] }).compile();

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AappModule

BAppModule

CApplicationModule

DMainModule

Attempts:

3 left

💡 Hint

Common Mistakes

Using lowercase 'appModule' which is invalid

Using incorrect module names like 'MainModule'

The main application module is usually named AppModule and should be imported as is.

3fill in blank

hard

Fix the error in the code to get the service instance from the testing module.

NestJS

const service = moduleRef.[1](MyService);

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AgetService

Bfetch

Cretrieve

Dget

Attempts:

3 left

💡 Hint

Common Mistakes

Using non-existent methods like 'getService' or 'retrieve'

Confusing with HTTP fetch method

The correct method to get a provider instance from the testing module is get().

4fill in blank

hard

Fill both blanks to correctly initialize and close the NestJS application in the test.

NestJS

app = moduleRef.[1]();
await app.[2]();

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AcreateNestApplication

Binit

Cclose

Dstart

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'init' instead of 'createNestApplication' to create app

Using 'start' instead of 'close' to shut down app

Use createNestApplication() to create the app instance and close() to clean up after tests.

5fill in blank

hard

Fill all three blanks to write a test that checks if the service method returns the expected value.

NestJS

it('should return expected result', async () => {
  const result = await service.[1]();
  expect(result).[2]([3]);
});

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AgetData

BtoEqual

C'expected value'

DtoBe

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'toBe' which checks identity instead of 'toEqual' for value equality

Using wrong method names on service

The test calls getData() on the service, then expects the result to equal the string 'expected value'.