Nest can't resolve dependencies of the ProductService (?). Please verify whether [0] argument is available in the current context.

I am having trouble setting up an API that uses MongoDb.

I have a feature Module: ProductsModule which is imported in my AppModule together with the MongooseModule.

When I try to inject my ProductService into my ProductsController, I get the following error: Nest can’t resolve dependencies of the ProductService (?). Please verify whether [0] argument is available in the current context.

I already saw several issues with the same problem, but none of them could give a solution for me. Thanks for the help!

Here is my setup:

- AppModule

import { Module } from '@nestjs/common';
import { MongooseModule } from '@nestjs/mongoose';
import { ProductsModule } from 'products/products.module';
import { Mongoose } from 'mongoose';

@Module({
  imports: [
    MongooseModule.forRoot(
      'mongodb://username:[e-mail]:37620/store',
    ),
    ProductsModule,
  ],
})
export class AppModule {}

- ProductsModule

import { Module } from '@nestjs/common';
import { MongooseModule } from '@nestjs/mongoose';

import { ProductSchema } from './schemas/product.schema';
import { ProductService } from './product.service';
import { ProductsController } from './products.controller';

@Module({
  imports: [
  MongooseModule.forFeature([
      {
        name: 'Product',
        schema: ProductSchema,
      },
    ]),
  ],
  controllers: [ProductsController],
  providers: [ProductService],
})
export class ProductsModule {}

- ProductsController

import { Body, Controller, Delete, Get, Param, Post, Put } from '@nestjs/common';

import { CreateProductDto } from './dto/create-product.dto';
import { Product } from './interfaces/product.interface';
import { ProductService } from './product.service';

@Controller('products')
export class ProductsController {
  constructor(private readonly productService: ProductService) {}

  @Get()
  async findAll(): Promise<Product[]> {
    return this.productService.findAll();
  }

  @Post()
  async create(@Body() createProductDto: CreateProductDto) {
    this.productService.create(createProductDto);
  }
}

- ProductService

import { Injectable } from '@nestjs/common';
import { InjectModel } from '@nestjs/mongoose';
import { Model } from 'mongoose';

import { PRODUCT_MODEL_TOKEN } from '../constants';
import { CreateProductDto } from './dto/create-product.dto';
import { Product } from './interfaces/product.interface';

@Injectable()
export class ProductService {
  constructor(@InjectModel(PRODUCT_MODEL_TOKEN) private readonly productModel: Model<Product>) {}

  async create(createProductDto: CreateProductDto): Promise<Product> {
    const createdProduct = new this.productModel(createProductDto);
    return await createdProduct.save();
  }

  async findAll(): Promise<Product[]> {
    return await this.productModel.find().exec();
  }
}

- Constants export const PRODUCT_MODEL_TOKEN = 'ProductModelToken';

[AntoineMaitre]

@ArneTesch That’s because in your ProductsModule you defined your DB provider’s name as 'Product' and not 'ProductModelToken'

- ProductsModule

import { Module } from '@nestjs/common';
import { MongooseModule } from '@nestjs/mongoose';

import { ProductSchema } from './schemas/product.schema';
import { ProductService } from './product.service';
import { ProductsController } from './products.controller';

@Module({
  imports: [
  MongooseModule.forFeature([
      {
        name: 'Product', // <== This is the name of what you'll use later in your `@InjectModel()`
        schema: ProductSchema,
      },
    ]),
  ],
  controllers: [ProductsController],
  providers: [ProductService],
})
export class ProductsModule {}

[lock[bot]]

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