feat: add backend-mock app

apps/backend-mock/src/modules/database/database.service.spec.ts

@@ -0,0 +1,19 @@
+import { Test, TestingModule } from '@nestjs/testing';
+
+import { DatabaseService } from './database.service';
+
+describe('databaseService', () => {
+  let service: DatabaseService;
+
+  beforeEach(async () => {
+    const module: TestingModule = await Test.createTestingModule({
+      providers: [DatabaseService],
+    }).compile();
+
+    service = module.get<DatabaseService>(DatabaseService);
+  });
+
+  it('should be defined', () => {
+    expect(service).toBeDefined();
+  });
+});