test: create initial unit tests

src/users/users.service.spec.ts

@@ -1,18 +1,25 @@
 import { Test, TestingModule } from "@nestjs/testing";
+import { UserRepository } from "./user.repository";
 import { UsersService } from "./users.service";
 
 describe("UsersService", () => {
   let service: UsersService;
+  let userRepository: UserRepository;
 
   beforeEach(async () => {
     const module: TestingModule = await Test.createTestingModule({
-      providers: [UsersService],
+      providers: [
+        UsersService,
+        { provide: UserRepository, useFactory: () => ({}) },
+      ],
     }).compile();
 
     service = module.get<UsersService>(UsersService);
+    userRepository = module.get<UserRepository>(UserRepository);
   });
 
   it("should be defined", () => {
     expect(service).toBeDefined();
+    expect(userRepository).toBeDefined();
   });
 });