Nestjs with TypeORM - Cannot read properties of undefined / No metadata was found - server starts all routes without error at startup

Question

I am currently trying to build a simple Nestjs Api (Nestjs v9, TypeORM v9, postgres:14-alpine). The application has no logic yet, but already has some routes, as you can see from the output:

[12:28:58 AM] Found 0 errors. Watching for file changes.

[Nest] 22189  - 05/19/2023, 12:28:59 AM     LOG [NestFactory] Starting Nest application...
[Nest] 22189  - 05/19/2023, 12:28:59 AM     LOG [InstanceLoader] TypeOrmModule dependencies initialized +28ms
[Nest] 22189  - 05/19/2023, 12:28:59 AM     LOG [InstanceLoader] PassportModule dependencies initialized +0ms
[Nest] 22189  - 05/19/2023, 12:28:59 AM     LOG [InstanceLoader] JwtModule dependencies initialized +0ms
[Nest] 22189  - 05/19/2023, 12:28:59 AM     LOG [InstanceLoader] JwtModule dependencies initialized +0ms
[Nest] 22189  - 05/19/2023, 12:28:59 AM     LOG [InstanceLoader] AppModule dependencies initialized +0ms
[Nest] 22189  - 05/19/2023, 12:28:59 AM     LOG [InstanceLoader] UsersModule dependencies initialized +0ms
[Nest] 22189  - 05/19/2023, 12:28:59 AM     LOG [InstanceLoader] TypeOrmCoreModule dependencies initialized +61ms
[Nest] 22189  - 05/19/2023, 12:28:59 AM     LOG [InstanceLoader] TypeOrmModule dependencies initialized +1ms
[Nest] 22189  - 05/19/2023, 12:28:59 AM     LOG [InstanceLoader] TypeOrmModule dependencies initialized +0ms
[Nest] 22189  - 05/19/2023, 12:28:59 AM     LOG [InstanceLoader] QuestionsModule dependencies initialized +7ms
[Nest] 22189  - 05/19/2023, 12:28:59 AM     LOG [InstanceLoader] AuthModule dependencies initialized +0ms
[Nest] 22189  - 05/19/2023, 12:28:59 AM     LOG [RoutesResolver] AppController {/}: +7ms
[Nest] 22189  - 05/19/2023, 12:28:59 AM     LOG [RouterExplorer] Mapped {/, GET} route +1ms
[Nest] 22189  - 05/19/2023, 12:28:59 AM     LOG [RoutesResolver] AuthController {/auth}: +0ms
[Nest] 22189  - 05/19/2023, 12:28:59 AM     LOG [RouterExplorer] Mapped {/auth/signup, POST} route +1ms
[Nest] 22189  - 05/19/2023, 12:28:59 AM     LOG [RouterExplorer] Mapped {/auth/signin, POST} route +0ms
[Nest] 22189  - 05/19/2023, 12:28:59 AM     LOG [RouterExplorer] Mapped {/auth/test, POST} route +0ms
[Nest] 22189  - 05/19/2023, 12:28:59 AM     LOG [RoutesResolver] UserController {/users}: +1ms
[Nest] 22189  - 05/19/2023, 12:28:59 AM     LOG [RouterExplorer] Mapped {/users, POST} route +0ms
[Nest] 22189  - 05/19/2023, 12:28:59 AM     LOG [RouterExplorer] Mapped {/users/login, POST} route +1ms
[Nest] 22189  - 05/19/2023, 12:28:59 AM     LOG [RouterExplorer] Mapped {/users, GET} route +0ms
[Nest] 22189  - 05/19/2023, 12:28:59 AM     LOG [RoutesResolver] QuestionsController {/questions}: +0ms
[Nest] 22189  - 05/19/2023, 12:28:59 AM     LOG [RouterExplorer] Mapped {/questions, POST} route +0ms
[Nest] 22189  - 05/19/2023, 12:28:59 AM     LOG [RouterExplorer] Mapped {/questions, GET} route +1ms
[Nest] 22189  - 05/19/2023, 12:28:59 AM     LOG [RouterExplorer] Mapped {/questions/:id, GET} route +0ms
[Nest] 22189  - 05/19/2023, 12:28:59 AM     LOG [RouterExplorer] Mapped {/questions/:id, PUT} route +0ms
[Nest] 22189  - 05/19/2023, 12:28:59 AM     LOG [RouterExplorer] Mapped {/questions/:id, DELETE} route +1ms
[Nest] 22189  - 05/19/2023, 12:28:59 AM     LOG [RouterExplorer] Mapped {/questions/:id/markAsRead, POST} route +0ms
[Nest] 22189  - 05/19/2023, 12:28:59 AM     LOG [RouterExplorer] Mapped {/questions/unread, GET} route +0ms
[Nest] 22189  - 05/19/2023, 12:28:59 AM     LOG [NestApplication] Nest application successfully started +2ms

Also, the connection to Postgres (Docker image) works and three tables are automatically created at startup.

However, as soon as I send a post request via Postman to http://localhost:3000/users with the following JSON object in the body (PS: Get Request does not work either):

{
    "username": "testUser",
    "password": "testPassword"
}

I receive from Postman :

{ "statusCode": 500, "message": "Internal server error" }

And in the Nestjs an error:

ERROR [ExceptionsHandler] Cannot read properties of undefined (reading 'create') TypeError: Cannot read properties of undefined (reading 'create') at UserRepository.create at UsersService.createUser at UserController.createUser

Here is my code:

Controller:

// src/users/users.controller.ts

import { Controller, Get, Post, Body } from '@nestjs/common';
import { UsersService } from './users.service';
import { AuthService } from '../auth/auth.service';
import { CreateUserDto } from './dto/create-user.dto';
import { AuthCredentialsDto } from '../auth/dto/auth-credentials.dto';

@Controller('users')
export class UserController {
  constructor(
    private readonly usersService: UsersService,
    private readonly authService: AuthService,
  ) {}

  @Post()
  async createUser(@Body() createUserDto: CreateUserDto) {
    return this.usersService.createUser(createUserDto);
  }

  // more code
}

Service:

// src/users/users.service.ts

import { Injectable } from '@nestjs/common';
import { UserRepository } from './user.repository';
import { InjectRepository } from '@nestjs/typeorm';
import { CreateUserDto } from './dto/create-user.dto';

@Injectable()
export class UsersService {
  constructor(
    @InjectRepository(UserRepository)
    private userRepository: UserRepository,
  ) {}

  async createUser(createUserDto: CreateUserDto) {
    const user = this.userRepository.create(createUserDto);
    await this.userRepository.save(user);
    return user;
  }

  // more code
}

Module:

// src/users/users.module.ts

import { Module } from '@nestjs/common';
import { UsersService } from './users.service';
import { UserRepository } from './user.repository';
import { JwtModule } from '@nestjs/jwt';
import { PassportModule } from '@nestjs/passport';
import { UserController } from './users.controller';
import { AuthService } from '../auth/auth.service';
import { TypeOrmModule } from '@nestjs/typeorm';

@Module({
  controllers: [UserController],
  imports: [
    TypeOrmModule.forFeature([UserRepository]),
    JwtModule.register({}),
    PassportModule.register({ defaultStrategy: 'jwt' }),
  ],
  providers: [UsersService, UserRepository, AuthService],
})
export class UsersModule {}

TypeORM is configured in my app.module and the connection is working:

// src/app.module.ts

import { Module } from '@nestjs/common';
import { AppController } from './app.controller';
import { AppService } from './app.service';
import { AuthModule } from './auth/auth.module';
import { UsersModule } from './users/users.module';
import { QuestionsModule } from './questions/questions.module';
import { UserEntity } from './users/user.entity';
import { QuestionEntity } from './questions/question.entity';
import { UserQuestionEntity } from './questions/user-question.entity';
import { TypeOrmModule } from '@nestjs/typeorm';

@Module({
  imports: [
    TypeOrmModule.forRoot({
      type: 'postgres',
      host: 'localhost',
      port: 5432,
      username: 'test',
      password: 'test',
      database: 'test',
      entities: [UserEntity, QuestionEntity, UserQuestionEntity],
      synchronize: true,
    }),
    AuthModule,
    UsersModule,
    QuestionsModule,
  ],
  controllers: [AppController],
  providers: [AppService],
})
export class AppModule {}

I don't understand what the issue is and how to fix it. Tell me if you want me to show you some other files.

Update:

User Repository:

// src/users/user.repository.ts

import { EntityRepository, Repository } from 'typeorm';
import { UserEntity } from './user.entity';

@EntityRepository(UserEntity)
export class UserRepository extends Repository<UserEntity> {}

User Entity:

// src/users/user.entity.ts

import { UserQuestionEntity } from 'src/questions/user-question.entity';
import { Entity, Column, PrimaryGeneratedColumn, OneToMany } from 'typeorm';

@Entity('users')
export class UserEntity {
  @PrimaryGeneratedColumn()
  id: number;

  @Column({ unique: true })
  username: string;

  @Column()
  password: string;

  @OneToMany(() => UserQuestionEntity, (userQuestion) => userQuestion.user)
  userQuestions: UserQuestionEntity[];
}

@FaristaLatuconsina done. I have just updated my post. Let me know if you want to see something else. — r00k13, May 19 '23 at 09:30
So the answer by @Hai Alison is right, you have to inject the entity into the @InjectRepository() decorator, not the repository itself — Farista Latuconsina, May 19 '23 at 11:07
@FaristaLatuconsina I can't change it without breaking everything. I also adjusted user.module, TypeOrmModule.forFeature([UserEntity]). But now the Nest application doesn't start anymore. Nest can't resolve dependencies of the AuthService (?, JwtService). — r00k13, May 19 '23 at 11:42
@FaristaLatuconsina I searched the project for all places where UserRepository was used and replaced everywhere there and loaded it correctly. Finally the error is gone. Either they used to do it this way and it no longer works in the new Nestjs version, or you can no longer trust any tutorial. — r00k13, May 19 '23 at 11:56

score 1 · Accepted Answer · answered May 19 '23 at 02:17

1

the cause is here:

private userRepository: UserRepository,

you should put your entity here like this below:


    @InjectRepository(UserEntity)
    private userRepository: Repository<UserEntity>,

answered May 19 '23 at 02:17

Hai Alison

419
2
9

I can't change it without breaking everything. I also adjusted user.module, TypeOrmModule.forFeature([UserEntity]). But now the Nest application doesn't start anymore. Nest can't resolve dependencies of the AuthService (?, JwtService). – r00k13 May 19 '23 at 11:43
I searched the project for all places where UserRepository was used and replaced everywhere there and loaded it correctly. Finally the error is gone. Either they used to do it this way and it no longer works in the new Nestjs version, or you can no longer trust any tutorial. Thanks. – r00k13 May 19 '23 at 11:57

Nestjs with TypeORM - Cannot read properties of undefined / No metadata was found - server starts all routes without error at startup

1 Answers1