fix: 🐛 remove null type in getUser response

libs/users/interface-adapters/src/lib/resolver/users.resolver.spec.ts

@@ -1,30 +1,62 @@
 import { Test, TestingModule } from '@nestjs/testing';
-import { UsersService } from '@users/application';
-
+import { GetUserByIdUseCase } from '@users/application';
 import { UsersResolver } from './users.resolver';
+import { UserDto } from '../dto/user.dto';
 
 describe('UsersResolver', () => {
   let resolver: UsersResolver;
-  let service: UsersService;
+  let getUserByIdUseCase: jest.Mocked<GetUserByIdUseCase>;
 
   beforeEach(async () => {
+    getUserByIdUseCase = {
+      execute: jest.fn(),
+    } as any;
+
     const module: TestingModule = await Test.createTestingModule({
       providers: [
         UsersResolver,
         {
-          provide: UsersService,
-          useValue: {
-            findOneById: jest.fn(),
-          },
+          provide: GetUserByIdUseCase,
+          useValue: getUserByIdUseCase,
         },
       ],
     }).compile();
 
     resolver = module.get<UsersResolver>(UsersResolver);
-    service = module.get<UsersService>(UsersService);
   });
 
   it('should be defined', () => {
     expect(resolver).toBeDefined();
   });
+
+  describe('getUser', () => {
+    it('should return a UserDto when user is found', async () => {
+      const mockUser = {
+        id: '1',
+        email: '[email protected]',
+        firstName: 'John',
+        lastName: 'Doe'
+      };
+      getUserByIdUseCase.execute.mockResolvedValue(mockUser);
+
+      const result = await resolver.getUser('1');
+
+      expect(result).toBeInstanceOf(UserDto);
+      expect(result).toEqual(new UserDto(
+        mockUser.id,
+        mockUser.email,
+        mockUser.firstName,
+        mockUser.lastName
+      ));
+      expect(getUserByIdUseCase.execute).toHaveBeenCalledWith('1');
+    });
+
+    it('should propagate errors from use case', async () => {
+      const error = new Error('Test error');
+      getUserByIdUseCase.execute.mockRejectedValue(error);
+
+      await expect(resolver.getUser('1')).rejects.toThrow(error);
+      expect(getUserByIdUseCase.execute).toHaveBeenCalledWith('1');
+    });
+  });
 });

libs/users/interface-adapters/src/lib/resolver/users.resolver.ts

@@ -1,20 +1,18 @@
 import { Args, ID, Query, Resolver } from '@nestjs/graphql';
-import { UsersService } from '@users/application';
+import { GetUserByIdUseCase } from '@users/application';
 import { User } from '@users/domain';
 
 import { UserDto } from '../dto/user.dto';
 
 @Resolver(() => UserDto)
 export class UsersResolver {
-  constructor(private usersService: UsersService) {}
+  constructor(private readonly getUserByIdUseCase: GetUserByIdUseCase) {}
 
   @Query(() => UserDto, { nullable: true })
-  async getUser(@Args({ name: 'id', type: () => ID }) id: string): Promise<UserDto | null> {
-    const user: User| null = await this.usersService.findOneById(id);
-
-    if (!user) {
-      return null;
-    }
+  async getUser(
+    @Args({ name: 'id', type: () => ID }) id: string,
+  ): Promise<UserDto> {
+    const user: User = await this.getUserByIdUseCase.execute(id);
 
     return new UserDto(user.id, user.email, user.firstName, user.lastName);
   }

libs/users/interface-adapters/src/lib/users.module.ts

@@ -1,6 +1,10 @@
 import { Module } from '@nestjs/common';
 import { DatabaseModule } from '@shared/infrastructure-mongoose';
-import { UsersService, GetUserByIdUseCase, GetUserByEmailUseCase } from '@users/application';
+import {
+  UsersService,
+  GetUserByIdUseCase,
+
+} from '@users/application';
 import {
   MongooseUsersRepository,
   UserDocument,
@@ -16,7 +20,6 @@ import { UsersResolver } from './resolver/users.resolver';
     UsersResolver,
     UsersService,
     GetUserByIdUseCase,
-    GetUserByEmailUseCase,
     {
       provide: USERS_REPOSITORY,
       useClass: MongooseUsersRepository,