Can't inject services which extend RepositoryService

[kairauer]

I tried to implement a custom validator with class-validator https://github.com/typestack/class-validator#custom-validation-classes. I used the example project from this repository.

I added the following class:

import { ValidatorConstraint, ValidatorConstraintInterface } from 'class-validator';
import { Injectable } from '@nestjs/common';
import { UsersService } from './users.service';

@ValidatorConstraint({ name: 'doesUserAlreadyExist', async: true })
@Injectable()
export class DoesUserAlreadyExist implements ValidatorConstraintInterface {
  constructor(private usersService: UsersService) {}

  async validate(text: string) {
    const users = await this.usersService.getMany({
        filter: [
            {
                field: 'email',
                operator: 'eq',
                value: text
            }
        ]
    });
    return users.length === 0 ? true : false;
  }
}

And added the validator to the User class (Entity):

...
  @Validate(DoesUserAlreadyExist, {
    message: 'User already exists',
  })
  @Column({ type: 'varchar', length: 255, nullable: false, unique: true })
  email: string;
...

I get the following error:

/Users/kai/Development/NodeJS/crud/integration/typeorm/node_modules/@nestjs/typeorm/dist/common/typeorm.utils.js:8
    return `${entity.name}Repository`;
                     ^
TypeError: Cannot read property 'name' of undefined
    at Object.getRepositoryToken (/Users/kai/Development/NodeJS/crud/integration/typeorm/node_modules/@nestjs/typeorm/dist/common/typeorm.utils.js:8:22)
    at Object.exports.InjectRepository (/Users/kai/Development/NodeJS/crud/integration/typeorm/node_modules/@nestjs/typeorm/dist/common/typeorm.decorators.js:5:72)
    at Object.<anonymous> (/Users/kai/Development/NodeJS/crud/integration/typeorm/src/users/users.service.ts:12:16)
    at Module._compile (internal/modules/cjs/loader.js:738:30)
    at Module.m._compile (/Users/kai/Development/NodeJS/crud/integration/typeorm/node_modules/ts-node/src/index.ts:439:23)
    at Module._extensions..js (internal/modules/cjs/loader.js:749:10)
    at Object.require.extensions.(anonymous function) [as .ts] (/Users/kai/Development/NodeJS/crud/integration/typeorm/node_modules/ts-node/src/index.ts:442:12)
    at Module.load (internal/modules/cjs/loader.js:630:32)
    at tryModuleLoad (internal/modules/cjs/loader.js:570:12)
    at Function.Module._load (internal/modules/cjs/loader.js:562:3)

If I remove the injected UsersService dependency injection from the DoesUserAlreadyExist class everything works again.
Is it not possible to use the services which extends the RepositoryService service? Or is there another way to execute the repository methods (getMany, getOne, etc.)?

[michaelyali]

Ok, could you please create a service as you normally do (not a RepositoryService, but just a dummy service) and inject it to your DoesUserAlreadyExist. And tell me if you still get this error. Thanks

[kairauer]

I created the following Service:

import { Injectable } from '@nestjs/common';

@Injectable()
export class UsersTestService {
  constructor() {
    console.log('UsersTestService');
  }
}

added the service to the UsersModule provider and injected the service in the DoesUserAlreadyExist validator:

...
constructor(private usersTestService: UsersTestService) {}
...

Everything works fine with this dummy service. Is there another way to execute repository methods?

[michaelyali]

@kairauer
And if you inject TypeORM repository into your dummy service, would you be able to see that error in this case?

[kairauer]

I changed the dummy service:

import { Injectable } from '@nestjs/common';
import { Repository } from 'typeorm';
import { User } from './user.entity';

@Injectable()
export class UsersTestService {
  constructor(private userRepository: Repository<User>) {
    console.log('UsersTestService', this.userRepository);
  }
}

Now I get an error again:

Error: Nest can't resolve dependencies of the UsersTestService (?). Please make sure that the argument at index [0] is available in the UsersModule context.
    at Injector.lookupComponentInExports (/Users/kai/Development/NodeJS/crud/integration/typeorm/node_modules/@nestjs/core/injector/injector.js:144:19)
    at processTicksAndRejections (internal/process/next_tick.js:81:5)
    at process.runNextTicks [as _tickCallback] (internal/process/next_tick.js:51:3)
    at Function.Module.runMain (internal/modules/cjs/loader.js:804:11)
    at Object.<anonymous> (/Users/kai/Development/NodeJS/crud/integration/typeorm/node_modules/ts-node/src/bin.ts:157:12)
    at Module._compile (internal/modules/cjs/loader.js:738:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:749:10)
    at Module.load (internal/modules/cjs/loader.js:630:32)
    at tryModuleLoad (internal/modules/cjs/loader.js:570:12)
    at Function.Module._load (internal/modules/cjs/loader.js:562:3)

But I am pretty sure, that I injected a service (which injected the repository) in the past like its mentioned in the docs: https://docs.nestjs.com/recipes/sql-typeorm
Any ideas? And by the way, thanks for the fast response 👍

[michaelyali]

Now you get another error, and it's not what I'm trying to get. We need to reproduce the first error.
So, as I can see, you're trying to inject repository in a wrong way. Please try this and tell me the result:

import { Injectable } from '@nestjs/common';
import { Repository } from 'typeorm';
import { InjectRepository } from '@nestjs/typeorm';
import { User } from './user.entity';

@Injectable()
export class UsersTestService {
  constructor(@InjectRepository(User) private userRepository: Repository<User>) {
    console.log('UsersTestService', this.userRepository);
  }
}

[kairauer]

Yes, you are right, that wasn't the right way to inject the repository. I tried it with your solution, now I get nearly the same error as in my first post:

TypeError: Cannot read property 'name' of undefined
    at Object.getRepositoryToken (/Users/kai/Development/NodeJS/crud/integration/typeorm/node_modules/@nestjs/typeorm/dist/common/typeorm.utils.js:8:22)
    at Object.exports.InjectRepository (/Users/kai/Development/NodeJS/crud/integration/typeorm/node_modules/@nestjs/typeorm/dist/common/typeorm.decorators.js:5:72)
    at Object.<anonymous> (/Users/kai/Development/NodeJS/crud/integration/typeorm/src/users/test.service.ts:8:16)
    at Module._compile (internal/modules/cjs/loader.js:738:30)
    at Module.m._compile (/Users/kai/Development/NodeJS/crud/integration/typeorm/node_modules/ts-node/src/index.ts:439:23)
    at Module._extensions..js (internal/modules/cjs/loader.js:749:10)
    at Object.require.extensions.(anonymous function) [as .ts] (/Users/kai/Development/NodeJS/crud/integration/typeorm/node_modules/ts-node/src/index.ts:442:12)
    at Module.load (internal/modules/cjs/loader.js:630:32)
    at tryModuleLoad (internal/modules/cjs/loader.js:570:12)
    at Function.Module._load (internal/modules/cjs/loader.js:562:3)

So, it seems like it's not caused by the extended RepositoryService class, right? I could fork the repo and implement the changes I did, if that helps to debug this.

[michaelyali]

Yes, that was my point. And, in general, I think it has nothing to do with RepositoryService or with NestJs, but I think it's a TypeORM issue instead.

[kairauer]

To anyone else who gets a similar issue, I think this is related to this issue: nestjs/nest#528