Implement task #139 - test

[brian-ai-assistant]

To start unit testing for the project, you will need to create test files for each module or component in your application. These test files should be placed in a separate directory, such as 'tests', and should follow a naming convention, such as appending '.spec' to the original file name. For example, if you have a file named 'app.module.ts', the corresponding test file should be named 'app.module.spec.ts'.

In each test file, you can write test cases using a testing framework such as Jest, which is commonly used with NestJS. These test cases should cover different scenarios and edge cases to ensure that your code behaves correctly.

Here is a sample test file for the 'AppModule':

describe('AppModule', () => {
  let appModule: AppModule;

  beforeEach(async () => {
    const moduleRef = await Test.createTestingModule({
      imports: [],
      controllers: [AppController],
      providers: [AppService],
    }).compile();

    appModule = moduleRef.get<AppModule>(AppModule);
  });

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

These test files can be executed using the testing command provided by your build tool, such as 'npm test' or 'yarn test'. The test results will then be displayed, indicating whether each test case passed or failed.

Commit message: Added unit tests for the project