Automock

Automock streamlines the unit testing process by auto-generating mock objects for class dependencies within dependency injection environments. With compatibility across various DI and testing frameworks, you can focus on crafting test cases instead of manual mock configurations, enhancing your unit testing journey.

↗️ Documentation    ↗️ API Reference

Core Features

🚀 Zero-Setup Mocking - Automatically generate mock objects, eliminate manual setup, reduce boilerplate code.

🔍 Type-Safe Mocks - Leverage TypeScript's power with mocks that retain the same type as real objects.

🔄 Consistent Test Architecture - Tests will follow a consistent syntax and structure, making them easier to read and maintain.

📈 Optimized Performance - By bypassing the actual DI container, unit tests run significantly faster.

🌐 Community & Support - Join a growing community of developers.

Quick Example

Take a look at the following example (using Jest, but the same applies for Sinon):

Consider the following UserService class:

export class Database {
  async getUsers(): Promise<User[]> { ... }
}

export class UserService {
  constructor(private database: Database) {}

  async getAllUsers(): Promise<User[]> {
    return this.database.getUsers();
  }
}

Let's create a unit test for this class using Automock:

import { TestBed } from '@automock/jest';
import { Database, UserService } from './user.service'; 

describe('User Service Unit Spec', () => {
  let userService: UserService; // << Declare the "unit under test"
  let database: jest.Mocked<Database>; // Declare a mocked dependency

  beforeAll(() => {
    const { unit, unitRef } = TestBed.create(UserService).compile(); // << Automock's stuff

    userService = unit;
    database = unitRef.get(Database); // << Retreive a dependency from the unit/class 
  });

  // All dependencies are mocked before the test is written 🚀
  test('should return users from the database', async () => {
    const mockUsers: User[] = [{ id: 1, name: 'John' }, { id: 2, name: 'Jane' }];
    database.getUsers.mockResolvedValue(mockUsers);

    const users = await userService.getAllUsers();

    expect(database.getUsers).toHaveBeenCalled();
    expect(users).toEqual(mockUsers);
  });
});

With the use of the TestBed, an instance of the UserService class can be created with mock objects automatically generated for its dependencies. During the test, we have direct access to the automatically generated mock object for the Database dependency (database). By stubbing the getUsers() method of the database mock object, we can define its behavior and make sure it resolves with a specific set of mock users.

Automock improves upon the existing unit testing procedures of DI frameworks by creating a virtual DI container. There is an array of advantages to this change:

• Speed: By simulating the actual DI container in the testing environment, Automock speeds up execution times.

• Efficiency: Developers are therefore able to focus on writing the test logic instead of grappling with the complexities of test setup.

• Isolation: Each test runs independently with mock implementations automatically provided, creating a streamlined and interference-free testing environment.

↗️ For a full Step-by-Step example

:package: Installation

To fully integrate Automock into your testing and dependency injection framework, you'll need to install two packages: Automock package for your chosen testing framework, and the corresponding adapter for your DI framework.

1. Install the corresponding package for your testing framework:

$ npm i -D @automock/jest

For Sinon:

$ npm i -D @automock/sinon

1. And for your DI framework, install the appropriate Automock adapter (as a dev dependency):

No further configuration is required.

:arrows_counterclockwise: Migrating from v1.x to v2.0

The NestJS adapter came pre-bundled in v1.x. In v2.0, you'll need to install it manually:

$ npm i -D @automock/adapters.nestjs

For a detailed list of changes read Automock's v2.0 Release Notes.

That's about it. :smile_cat:

↗️ Migration guide

:scroll: License

Distributed under the MIT License. See LICENSE for more information.