refactor health module, improve code coverage

src/modules/health/tests/unit/repositories.health-indicator.usecase.spec.ts

@@ -12,7 +12,7 @@ const mockAdRepository = {
       return Promise.resolve(true);
     })
     .mockImplementation(() => {
-      throw new DatabaseErrorException('an error occured in the database');
+      throw new DatabaseErrorException('An error occured in the database');
     }),
 };
 
@@ -56,9 +56,11 @@ describe('RepositoriesHealthIndicatorUseCase', () => {
     });
 
     it('should throw an error if database is unavailable', async () => {
+      jest.spyOn(mockMessagePublisher, 'publish');
       await expect(
         repositoriesHealthIndicatorUseCase.isHealthy('repositories'),
       ).rejects.toBeInstanceOf(HealthCheckError);
+      expect(mockMessagePublisher.publish).toHaveBeenCalledTimes(1);
     });
   });
 });