- 1. API with NestJS #1. Controllers, routing and the module structure
- 2. API with NestJS #2. Setting up a PostgreSQL database with TypeORM
- 3. API with NestJS #3. Authenticating users with bcrypt, Passport, JWT, and cookies
- 4. API with NestJS #4. Error handling and data validation
- 5. API with NestJS #5. Serializing the response with interceptors
- 6. API with NestJS #6. Looking into dependency injection and modules
- 7. API with NestJS #7. Creating relationships with Postgres and TypeORM
- 8. API with NestJS #8. Writing unit tests
- 9. API with NestJS #9. Testing services and controllers with integration tests
- 10. API with NestJS #10. Uploading public files to Amazon S3
- 11. API with NestJS #11. Managing private files with Amazon S3
- 12. API with NestJS #12. Introduction to Elasticsearch
- 13. API with NestJS #13. Implementing refresh tokens using JWT
- 14. API with NestJS #14. Improving performance of our Postgres database with indexes
- 15. API with NestJS #15. Defining transactions with PostgreSQL and TypeORM
- 16. API with NestJS #16. Using the array data type with PostgreSQL and TypeORM
- 17. API with NestJS #17. Offset and keyset pagination with PostgreSQL and TypeORM
- 18. API with NestJS #18. Exploring the idea of microservices
- 19. API with NestJS #19. Using RabbitMQ to communicate with microservices
- 20. API with NestJS #20. Communicating with microservices using the gRPC framework
- 21. API with NestJS #21. An introduction to CQRS
- 22. API with NestJS #22. Storing JSON with PostgreSQL and TypeORM
- 23. API with NestJS #23. Implementing in-memory cache to increase the performance
- 24. API with NestJS #24. Cache with Redis. Running the app in a Node.js cluster
- 25. API with NestJS #25. Sending scheduled emails with cron and Nodemailer
- 26. API with NestJS #26. Real-time chat with WebSockets
- 27. API with NestJS #27. Introduction to GraphQL. Queries, mutations, and authentication
- 28. API with NestJS #28. Dealing in the N + 1 problem in GraphQL
- 29. API with NestJS #29. Real-time updates with GraphQL subscriptions
- 30. API with NestJS #30. Scalar types in GraphQL
- 31. API with NestJS #31. Two-factor authentication
- 32. API with NestJS #32. Introduction to Prisma with PostgreSQL
- 33. API with NestJS #33. Managing PostgreSQL relationships with Prisma
- 34. API with NestJS #34. Handling CPU-intensive tasks with queues
- 35. API with NestJS #35. Using server-side sessions instead of JSON Web Tokens
- 36. API with NestJS #36. Introduction to Stripe with React
- 37. API with NestJS #37. Using Stripe to save credit cards for future use
- 38. API with NestJS #38. Setting up recurring payments via subscriptions with Stripe
- 39. API with NestJS #39. Reacting to Stripe events with webhooks
- 40. API with NestJS #40. Confirming the email address
- 41. API with NestJS #41. Verifying phone numbers and sending SMS messages with Twilio
- 42. API with NestJS #42. Authenticating users with Google
- 43. API with NestJS #43. Introduction to MongoDB
- 44. API with NestJS #44. Implementing relationships with MongoDB
- 45. API with NestJS #45. Virtual properties with MongoDB and Mongoose
- 46. API with NestJS #46. Managing transactions with MongoDB and Mongoose
- 47. API with NestJS #47. Implementing pagination with MongoDB and Mongoose
- 48. API with NestJS #48. Definining indexes with MongoDB and Mongoose
- 49. API with NestJS #49. Updating with PUT and PATCH with MongoDB and Mongoose
- 50. API with NestJS #50. Introduction to logging with the built-in logger and TypeORM
- 51. API with NestJS #51. Health checks with Terminus and Datadog
- 52. API with NestJS #52. Generating documentation with Compodoc and JSDoc
- 53. API with NestJS #53. Implementing soft deletes with PostgreSQL and TypeORM
- 54. API with NestJS #54. Storing files inside a PostgreSQL database
- 55. API with NestJS #55. Uploading files to the server
- 56. API with NestJS #56. Authorization with roles and claims
- 57. API with NestJS #57. Composing classes with the mixin pattern
- 58. API with NestJS #58. Using ETag to implement cache and save bandwidth
- 59. API with NestJS #59. Introduction to a monorepo with Lerna and Yarn workspaces
- 60. API with NestJS #60. The OpenAPI specification and Swagger
- 61. API with NestJS #61. Dealing with circular dependencies
- 62. API with NestJS #62. Introduction to MikroORM with PostgreSQL
- 63. API with NestJS #63. Relationships with PostgreSQL and MikroORM
- 64. API with NestJS #64. Transactions with PostgreSQL and MikroORM
- 65. API with NestJS #65. Implementing soft deletes using MikroORM and filters
- 66. API with NestJS #66. Improving PostgreSQL performance with indexes using MikroORM
- 67. API with NestJS #67. Migrating to TypeORM 0.3
- 68. API with NestJS #68. Interacting with the application through REPL
- 69. API with NestJS #69. Database migrations with TypeORM
- 70. API with NestJS #70. Defining dynamic modules
- 71. API with NestJS #71. Introduction to feature flags
- 72. API with NestJS #72. Working with PostgreSQL using raw SQL queries
- 73. API with NestJS #73. One-to-one relationships with raw SQL queries
- 74. API with NestJS #74. Designing many-to-one relationships using raw SQL queries
- 75. API with NestJS #75. Many-to-many relationships using raw SQL queries
- 76. API with NestJS #76. Working with transactions using raw SQL queries
- 77. API with NestJS #77. Offset and keyset pagination with raw SQL queries
- 78. API with NestJS #78. Generating statistics using aggregate functions in raw SQL
- 79. API with NestJS #79. Implementing searching with pattern matching and raw SQL
- 80. API with NestJS #80. Updating entities with PUT and PATCH using raw SQL queries
- 81. API with NestJS #81. Soft deletes with raw SQL queries
- 82. API with NestJS #82. Introduction to indexes with raw SQL queries
- 83. API with NestJS #83. Text search with tsvector and raw SQL
- 84. API with NestJS #84. Implementing filtering using subqueries with raw SQL
- 85. API with NestJS #85. Defining constraints with raw SQL
- 86. API with NestJS #86. Logging with the built-in logger when using raw SQL
- 87. API with NestJS #87. Writing unit tests in a project with raw SQL
- 88. API with NestJS #88. Testing a project with raw SQL using integration tests
- 89. API with NestJS #89. Replacing Express with Fastify
- 90. API with NestJS #90. Using various types of SQL joins
- 91. API with NestJS #91. Dockerizing a NestJS API with Docker Compose
- 92. API with NestJS #92. Increasing the developer experience with Docker Compose
- 93. API with NestJS #93. Deploying a NestJS app with Amazon ECS and RDS
- 94. API with NestJS #94. Deploying multiple instances on AWS with a load balancer
- 95. API with NestJS #95. CI/CD with Amazon ECS and GitHub Actions
- 96. API with NestJS #96. Running unit tests with CI/CD and GitHub Actions
- 97. API with NestJS #97. Introduction to managing logs with Amazon CloudWatch
- 98. API with NestJS #98. Health checks with Terminus and Amazon ECS
- 99. API with NestJS #99. Scaling the number of application instances with Amazon ECS
- 100. API with NestJS #100. The HTTPS protocol with Route 53 and AWS Certificate Manager
- 101. API with NestJS #101. Managing sensitive data using the AWS Secrets Manager
- 102. API with NestJS #102. Writing unit tests with Prisma
- 103. API with NestJS #103. Integration tests with Prisma
- 104. API with NestJS #104. Writing transactions with Prisma
- 105. API with NestJS #105. Implementing soft deletes with Prisma and middleware
- 106. API with NestJS #106. Improving performance through indexes with Prisma
- 107. API with NestJS #107. Offset and keyset pagination with Prisma
- 108. API with NestJS #108. Date and time with Prisma and PostgreSQL
- 109. API with NestJS #109. Arrays with PostgreSQL and Prisma
- 110. API with NestJS #110. Managing JSON data with PostgreSQL and Prisma
- 111. API with NestJS #111. Constraints with PostgreSQL and Prisma
- 112. API with NestJS #112. Serializing the response with Prisma
- 113. API with NestJS #113. Logging with Prisma
- 114. API with NestJS #114. Modifying data using PUT and PATCH methods with Prisma
- 115. API with NestJS #115. Database migrations with Prisma
- 116. API with NestJS #116. REST API versioning
- 117. API with NestJS #117. CORS – Cross-Origin Resource Sharing
- 118. API with NestJS #118. Uploading and streaming videos
- 119. API with NestJS #119. Type-safe SQL queries with Kysely and PostgreSQL
- 120. API with NestJS #120. One-to-one relationships with the Kysely query builder
- 121. API with NestJS #121. Many-to-one relationships with PostgreSQL and Kysely
- 122. API with NestJS #122. Many-to-many relationships with Kysely and PostgreSQL
- 123. API with NestJS #123. SQL transactions with Kysely
- 124. API with NestJS #124. Handling SQL constraints with Kysely
- 125. API with NestJS #125. Offset and keyset pagination with Kysely
- 126. API with NestJS #126. Improving the database performance with indexes and Kysely
- 127. API with NestJS #127. Arrays with PostgreSQL and Kysely
- 128. API with NestJS #128. Managing JSON data with PostgreSQL and Kysely
- 129. API with NestJS #129. Implementing soft deletes with SQL and Kysely
- 130. API with NestJS #130. Avoiding storing sensitive information in API logs
- 131. API with NestJS #131. Unit tests with PostgreSQL and Kysely
- 132. API with NestJS #132. Handling date and time in PostgreSQL with Kysely
- 133. API with NestJS #133. Introducing database normalization with PostgreSQL and Prisma
- 134. API with NestJS #134. Aggregating statistics with PostgreSQL and Prisma
- 135. API with NestJS #135. Referential actions and foreign keys in PostgreSQL with Prisma
- 136. API with NestJS #136. Raw SQL queries with Prisma and PostgreSQL range types
- 137. API with NestJS #137. Recursive relationships with Prisma and PostgreSQL
- 138. API with NestJS #138. Filtering records with Prisma
- 139. API with NestJS #139. Using UUID as primary keys with Prisma and PostgreSQL
- 140. API with NestJS #140. Using multiple PostgreSQL schemas with Prisma
- 141. API with NestJS #141. Getting distinct records with Prisma and PostgreSQL
- 142. API with NestJS #142. A video chat with WebRTC and React
- 143. API with NestJS #143. Optimizing queries with views using PostgreSQL and Kysely
- 144. API with NestJS #144. Creating CLI applications with the Nest Commander
- 145. API with NestJS #145. Securing applications with Helmet
- 146. API with NestJS #146. Polymorphic associations with PostgreSQL and Prisma
- 147. API with NestJS #147. The data types to store money with PostgreSQL and Prisma
- 148. API with NestJS #148. Understanding the injection scopes
- 149. API with NestJS #149. Introduction to the Drizzle ORM with PostgreSQL
- 150. API with NestJS #150. One-to-one relationships with the Drizzle ORM
- 151. API with NestJS #151. Implementing many-to-one relationships with Drizzle ORM
- 152. API with NestJS #152. SQL constraints with the Drizzle ORM
- 153. API with NestJS #153. SQL transactions with the Drizzle ORM
- 154. API with NestJS #154. Many-to-many relationships with Drizzle ORM and PostgreSQL
- 155. API with NestJS #155. Offset and keyset pagination with the Drizzle ORM
- 156. API with NestJS #156. Arrays with PostgreSQL and the Drizzle ORM
- 157. API with NestJS #157. Handling JSON data with PostgreSQL and the Drizzle ORM
- 158. API with NestJS #158. Soft deletes with the Drizzle ORM
- 159. API with NestJS #159. Date and time with PostgreSQL and the Drizzle ORM
- 160. API with NestJS #160. Using views with the Drizzle ORM and PostgreSQL
- 161. API with NestJS #161. Generated columns with the Drizzle ORM and PostgreSQL
- 162. API with NestJS #162. Identity columns with the Drizzle ORM and PostgreSQL
- 163. API with NestJS #163. Full-text search with the Drizzle ORM and PostgreSQL
- 164. API with NestJS #164. Improving the performance with indexes using Drizzle ORM
- 165. API with NestJS #165. Time intervals with the Drizzle ORM and PostgreSQL
- 166. API with NestJS #166. Logging with the Drizzle ORM
- 167. API with NestJS #167. Unit tests with the Drizzle ORM
- 168. API with NestJS #168. Integration tests with the Drizzle ORM
In the previous part of this series, we’ve focused on unit tests. This time, we look into integration tests. In this article, we explain their principles and how they differ from unit tests. We write a few of them using Jest to test our services. We also look into the SuperTest library to test our controllers.
Testing NestJS services with integration tests
When our unit tests pass, it indicates that parts of our system work well on their own. However, an application consists of many parts that should work well together. A job of an integration test is to verify that all the cogs in the wheel integrate. We can write such tests integrating two or more parts of the system.
Let’s test how AuthenticationService integrates with UsersService.
src/authentication/tests/authentication.service.spec.ts
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import { AuthenticationService } from '../authentication.service'; import { Test } from '@nestjs/testing'; import { ConfigService } from '@nestjs/config'; import { JwtService } from '@nestjs/jwt'; import { getRepositoryToken } from '@nestjs/typeorm'; import User from '../../users/user.entity'; import { UsersService } from '../../users/users.service'; import mockedJwtService from '../../utils/mocks/jwt.service'; import mockedConfigService from '../../utils/mocks/config.service'; describe('The AuthenticationService', () => { let authenticationService: AuthenticationService; let usersService: UsersService; beforeEach(async () => { const module = await Test.createTestingModule({ providers: [ UsersService, AuthenticationService, { provide: ConfigService, useValue: mockedConfigService }, { provide: JwtService, useValue: mockedJwtService }, { provide: getRepositoryToken(User), useValue: {} } ], }) .compile(); authenticationService = await module.get(AuthenticationService); usersService = await module.get(UsersService); }) describe('when accessing the data of authenticating user', async () => { it('should attempt to get the user by email', () => { const getByEmailSpy = jest.spyOn(usersService, 'getByEmail'); await authenticationService.getAuthenticatedUser('user@email.com', 'strongPassword'); expect(getByEmailSpy).toBeCalledTimes(1); }) }) }); |
The first thing to notice above is that we mock some of the services that we use. Even though we want to write an integration test, it does not mean that we need to include every part of the system.
Mocking some parts of the system
We need to decide how many parts of the system we want to include. Let’s assume that we want to test the integration of the AuthenticationService and UsersService. Going further, let’s also mock the bcrypt library.
Since our AuthenticationService directly imports it, it is not straightforward to mock. To do that, we need to use jest.mock.
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jest.mock('bcrypt'); |
Now that we explicitly state that we mock bcrypt, we can provide our implementation of it.
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import * as bcrypt from 'bcrypt'; describe('The AuthenticationService', () => { let bcryptCompare: jest.Mock; beforeEach(async () => { bcryptCompare = jest.fn().mockReturnValue(true); (bcrypt.compare as jest.Mock) = bcryptCompare; }); }); |
Thanks to declaring bcryptCompare at the top, we can now change its implementation for each test.
We do a similar thing for the repository.
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import User from '../../users/user.entity'; const mockedUser: User = { id: 1, email: 'user@email.com', name: 'John', password: 'hash', address: { id: 1, street: 'streetName', city: 'cityName', country: 'countryName' } } |
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import User from '../../users/user.entity'; import * as bcrypt from 'bcrypt'; import mockedUser from './user.mock'; jest.mock('bcrypt'); describe('The AuthenticationService', () => { let bcryptCompare: jest.Mock; let userData: User; let findUser: jest.Mock; beforeEach(async () => { bcryptCompare = jest.fn().mockReturnValue(true); (bcrypt.compare as jest.Mock) = bcryptCompare; userData = { ...mockedUser } findUser = jest.fn().mockResolvedValue(userData); const usersRepository = { findOne: findUser } }) }); |
Providing different implementations per test
Once we do all of the above, we can provide different implementations of our mocked services for various tests.
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describe('when accessing the data of authenticating user', () => { describe('and the provided password is not valid', () => { beforeEach(() => { bcryptCompare.mockReturnValue(false); }); it('should throw an error', async () => { await expect( authenticationService.getAuthenticatedUser('user@email.com', 'strongPassword') ).rejects.toThrow(); }) }) describe('and the provided password is valid', () => { beforeEach(() => { bcryptCompare.mockReturnValue(true); }); describe('and the user is found in the database', () => { beforeEach(() => { findUser.mockResolvedValue(userData); }) it('should return the user data', async () => { const user = await authenticationService.getAuthenticatedUser('user@email.com', 'strongPassword'); expect(user).toBe(userData); }) }) describe('and the user is not found in the database', () => { beforeEach(() => { findUser.mockResolvedValue(undefined); }) it('should throw an error', async () => { await expect( authenticationService.getAuthenticatedUser('user@email.com', 'strongPassword') ).rejects.toThrow(); }) }) }) }) |
Above, we specify how our mocks work in the beforeEach functions. Thanks to doing that, it would run before all the tests in a particular describe() block.
Check out this file in the repository, if you want to inspect the above test suite thoroughly.
Testing controllers
We perform another type of integration tests by performing real requests. By doing so, we can test our controllers. It is closer to how our application is used. To do so, we use the SuperTest library.
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npm install supertest |
Now, let’s test how the AuthenticationController integrates with AuthenticationService and UsersService.
We start by mocking some of the parts of the application.
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let app: INestApplication; let userData: User; beforeEach(async () => { userData = { ...mockedUser } const usersRepository = { create: jest.fn().mockResolvedValue(userData), save: jest.fn().mockReturnValue(Promise.resolve()) } const module = await Test.createTestingModule({ controllers: [AuthenticationController], providers: [ UsersService, AuthenticationService, { provide: ConfigService, useValue: mockedConfigService }, { provide: JwtService, useValue: mockedJwtService }, { provide: getRepositoryToken(User), useValue: usersRepository } ], }) .compile(); app = module.createNestApplication(); app.useGlobalPipes(new ValidationPipe()); await app.init(); }) |
Please notice that above we also need to apply the ValidationPipe if we want to verify our validation.
Once we have our module ready, we can perform some tests on it. Let’s start with the registration flow.
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describe('when registering', () => { describe('and using valid data', () => { it('should respond with the data of the user without the password', () => { const expectedData = { ...userData } delete expectedData.password; return request(app.getHttpServer()) .post('/authentication/register') .send({ email: mockedUser.email, name: mockedUser.name, password: 'strongPassword' }) .expect(201) .expect(expectedData); }) }) describe('and using invalid data', () => { it('should throw an error', () => { return request(app.getHttpServer()) .post('/authentication/register') .send({ name: mockedUser.name }) .expect(400) }) }) }) |
Above, we perform real HTTP requests and test the authentication/register endpoint. If we provide valid data, we expect it to work correctly. Otherwise, we expect it to throw an error.
Aside from simple tests like those above, we can perform more throughout ones. For example, we can verify the response headers. For a full list of SuperTest features, check out the documentation.
To see the whole controller test suite, check it out in the repository.
Summary
In this article, we’ve gone through ways to write integration tests for our NestJS API. Aside from testing how our services integrate, we’ve also used the SuperTest library and tested a controller. By writing integration tests, we can thoroughly verify if our app works as expected. Therefore, it is a topic worth diving into.
Thanks for good tutorials.
A question about the controller test. How do you use the global ClassSerializerInterceptor in the controller test?
I see that you have reverted to setting the createdUser.password = undefined which makes this test pass.
Is there a better way where you use the Nest serializations and is the problem with it not working due to supertest?
Found a solution: https://stackoverflow.com/questions/64578498/nestjs-supertest-e2e-tests-skip-serializer-interceptors
But not sure if creating a constructor inside the User class is the best approach.
I agree, constructor does not look like the best approach. Instead I used plainToClass method from class-transformer.
You can use Object.assign
Hi, how can we make a integration test to check if the cookie has been properly set after the login?
I’ve tryied to override localguard, but apparently the user never goes inside the request.
Hi, face that error. I can’t understand why it happened:
https://i.imgur.com/qUY9s7z.png
Me too, i face this problem, and don’t know how to solve it. Did you resolve yours ?
Thank you so much for making these super useful tutorials