NestJS : TypeError: Cannot read property 'get' of undefined

Question

I am trying to pass the connection parameters to mongodb by enviroment file and I am getting the following error

[Nest] 1176  - 12/10/2021 23:34:35   ERROR [ExceptionHandler] Cannot read property 'get' of undefined
TypeError: Cannot read property 'get' of undefined
    at MongoService.createMongooseOptions (/Users/Desarrollos/NestJS/nestjs-ventas-negocios/src/common/mongo/mongo.service.ts:20:41)
    at Function.<anonymous> (/Users/Desarrollos/NestJS/nestjs-ventas-negocios/node_modules/@nestjs/mongoose/dist/mongoose-core.module.js:135:120)
    at Generator.next (<anonymous>)
    at /Users/Desarrollos/NestJS/nestjs-ventas-negocios/node_modules/@nestjs/mongoose/dist/mongoose-core.module.js:20:71
    at new Promise (<anonymous>)
    at __awaiter (/Users/Desarrollos/NestJS/nestjs-ventas-negocios/node_modules/@nestjs/mongoose/dist/mongoose-core.module.js:16:12)
    at InstanceWrapper.useFactory [as metatype] (/Users/Desarrollos/NestJS/nestjs-ventas-negocios/node_modules/@nestjs/mongoose/dist/mongoose-core.module.js:135:45)
    at Injector.instantiateClass (/Users/Desarrollos/NestJS/nestjs-ventas-negocios/node_modules/@nestjs/core/injector/injector.js:294:55)
    at callback (/Users/Desarrollos/NestJS/nestjs-ventas-negocios/node_modules/@nestjs/core/injector/injector.js:43:41)
    at Injector.resolveConstructorParams (/Users/Desarrollos/NestJS/nestjs-ventas-negocios/node_modules/@nestjs/core/injector/injector.js:119:24)

This is the service mongo.service.ts

import { MongooseModuleOptions, MongooseOptionsFactory } from '@nestjs/mongoose';
import { Configuration } from '../../config/config.keys';
import { ConfigService } from '../../config/config.service';

export class MongoService implements MongooseOptionsFactory {
    constructor( private configService: ConfigService ) {}

    createMongooseOptions(): MongooseModuleOptions {

        const user     = this.configService.get(Configuration.DB_MONGO_USER);
        const password = this.configService.get(Configuration.DB_MONGO_PASSWORD);
        const server   = this.configService.get(Configuration.DB_MONGO_HOST);
        const database = this.configService.get(Configuration.DB_MONGO_DATABASE);

        return {
            uri: `mongodb://${user}:${password}@${server}/${database}?retryWrites=true&w=majority`,
        };
    }
}

And this I import it in the app.module.ts

@Module({
  imports: [
    MongooseModule.forRootAsync({
      useClass: MongoService,
    }),

Any suggestion, thanks, JM

Cambria

Did you search this site for cannot get property of undefined? There have been literally hundreds (if not thousands) of previous questions related to the same error asked (and answered) here before. Surely one of them can point out a way for you to solve this problem. – Thinia

Maybe you forgot to add @Injectable() above MongoService – Mistrustful

adding @Injectable I get the following error : Error: Nest can't resolve dependencies of the MongoService (?). Please make sure that the argument ConfigService at index [0] is available in the MongooseCoreModule context. – Cambria

Answer 1

You need 2 things here:

1. Your MongoService needs to be marked with @Injectable() so that Nest can read the metadata of the constructor and set up the injection properly

2. If your ConfigModule does not have a globally exported ConfigService, then in MongooseModule.forRootAsync() along with the useClass you need to have imports: [ConfigModule] so that you can inject the ConfigService

Hibben

Thanks Jay, I'm obviously connecting something wrong and I can't see it. With @Injectable() , I get the following error : ERROR [ExceptionHandler] Nest can't resolve dependencies of the MongoService (?). Please make sure that the argument ConfigService at index [0] is available in the MongooseCoreModule context. – Cambria

Did you add the ConfigModule to the MongooseModule.forRootAsync() options, like I mentioned in point 2? – Hibben

The same error : @Module({ imports: [ MongooseModule.forRootAsync({ imports: [ ConfigService ], useClass: MongoService, inject: [ConfigService], }), VentaNegociosModule, ConfigModule ], – Cambria

You have imports: [ConfigService], not imports: [ConfigModule]. You also don't need inject – Hibben

Answer 2

@Module({ 
  imports: [ 
    MongooseModule.forRootAsync({ 
      imports: [ ConfigModule ], 
      inject: [ConfigService],
      useClass: MongoService
  })
})

Massacre

Answer 3

After search for several posts, if you are using nx for nestjs and using esbuild for compiler, you might have this problem. The way to make it work is to change back to webpack, because esbuild is having issue with monorepo.

Ref: https://github.com/nrwl/nx/issues/20546

Berner

Answer 4

I think u fotgot add inject, try this:

@Module({
  imports: [
    UsersModule,
    JwtModule.registerAsync({
      useFactory: async (configService: ConfigService) => ({
        secretOrPrivateKey: 
        signOptions: {
      }),
      inject: [ConfigService], // i think u add line this
    }),

  ],
  controllers: [AuthController],
  providers: [AuthService],
})
export class AuthModule { }

Kristykristyn