Testing

Testing a @Controller

import { Bootstrap, get, Module } from '@rhtml/di';
import { FastifyModule } from '@rhtml/fastify';
import fastify from 'fastify';

import { HealthCheckController } from './healthcheck.controller';
import { HealthCheckService } from './healthcheck.service';
import { HealthCheckStatus } from './types';

describe('healthcheck controller', () => {
  let healthCheckController: HealthCheckController;
  let healthCheckService: HealthCheckService;

  beforeEach(async () => {
    @Module({
      imports: [
        FastifyModule.forRoot(fastify, {
          logger: true,
        }),
      ],
      providers: [HealthCheckService],
      bootstrap: [HealthCheckController],
    })
    class AppModule {}

    await Bootstrap(AppModule);
    healthCheckController = get(HealthCheckController);
    healthCheckService = get(HealthCheckService);
  });

  afterEach(() => {
    jest.restoreAllMocks();
  });

  it('should be defined', () => {
    expect(healthCheckController).toBeDefined();
  });

  it('should call the healthcheck service', async () => {
    const response = {
      server: { status: HealthCheckStatus.WORKING },
      database: { status: 'ok' },
    } as never;
    const spy = jest
      .spyOn(healthCheckService, 'checkServicesStatus')
      .mockResolvedValue(response);
    const result = await healthCheckController.healthCheck();
    expect(spy).toHaveBeenCalled();
    expect(result).toEqual(response);
  });
});

The provided TypeScript code is a test suite written using the Jest framework for testing. It tests a controller called HealthCheckController, which utilizes @rhtml/di for dependency injection and @rhtml/fastify for web server functionality.

Imports:

• @rhtml/di: Used for dependency injection.
• @rhtml/fastify: Used for integrating Fastify with the application.
• fastify: Represents the Fastify instance.
• jest: Testing framework.

Describing Test Suite:

• The describe() function is used to group test cases related to the "healthcheck controller".

Test Setup:

• healthCheckController and healthCheckService are declared outside the beforeEach() block to make them accessible across test cases.
• Inside beforeEach(), a module (AppModule) is defined using @Module decorator from @rhtml/di. It imports FastifyModule.forRoot() from @rhtml/fastify to configure Fastify.
• HealthCheckService is registered as a provider within the module.
• Bootstrap(AppModule) is awaited to initialize the module.
• Instances of HealthCheckController and HealthCheckService are obtained using get() function from @rhtml/di and assigned to healthCheckController and healthCheckService respectively.

Test Teardown:

• jest.restoreAllMocks() is used in the afterEach() block to restore all mocked functions after each test case.

Test Cases:

• The first test case checks if healthCheckController is defined.
• The second test case verifies if the healthCheck() method of HealthCheckController calls the checkServicesStatus() method of HealthCheckService. It mocks the checkServicesStatus() method using jest.spyOn() and verifies if it's called.
• It also checks if the result returned by healthCheckController.healthCheck() matches the expected response.

Overall, this code tests the behavior of the HealthCheckController by mocking its dependencies and ensuring that it interacts correctly with the HealthCheckService. It validates that the controller functions as expected when handling health check requests.

Testing a @Service

import { Bootstrap, Module, set } from '@rhtml/di';

import { HealthCheckService } from './healthcheck.service';
import { HealthCheckStatus } from './types';

describe('health check service', () => {
  let healthCheckService: HealthCheckService;

  beforeEach(async () => {
    @Module({
      providers: [HealthCheckService],
    })
    class AppModule {}

    await Bootstrap(AppModule);

    healthCheckService = set(HealthCheckService);
  });

  afterEach(() => {
    jest.restoreAllMocks();
  });

  it('should return WORKING status for the server and the correct status for the database', () => {
    const response = {
      server: {
        status: HealthCheckStatus.WORKING,
      },
    } as never;

    const result = healthCheckService.checkServicesStatus();

    expect(result).toEqual(response);
  });
});

The provided TypeScript code is a test suite written using the Jest framework for testing. It tests a service called HealthCheckService, which utilizes @rhtml/di for dependency injection.

Imports:

• The code imports necessary modules and libraries from @rhtml/di.

Describing Test Suite:

• The describe() function is used to group test cases related to the "health check service".

Test Setup:

• healthCheckService is declared outside the beforeEach() block to make it accessible across test cases.
• Inside beforeEach(), a module (AppModule) is defined using @Module decorator from @rhtml/di. It only provides the HealthCheckService as a provider.
• Bootstrap(AppModule) is awaited to initialize the module.
• The set() function from @rhtml/di is used to obtain an instance of HealthCheckService and assign it to healthCheckService.

Test Teardown:

• jest.restoreAllMocks() is used in the afterEach() block to restore all mocked functions after each test case.

Test Case:

• The test case verifies that the checkServicesStatus() method of HealthCheckService returns the expected response.
• It defines a response object with the expected structure and values.
• It calls the checkServicesStatus() method and assigns the result to result.
• It asserts that the result matches the response object using expect().toEqual().

Overall, this code tests the behavior of the HealthCheckService by verifying that its checkServicesStatus() method returns the expected response. It ensures that the service functions correctly when checking the status of services.