app.module.ts

import { Module } from '@nestjs/common';
import { MongooseModule } from '@nestjs/mongoose';
import { UsersModule } from './users/users.module';
import { PostsModule } from './posts/posts.module';

@Module({
  imports: [
    MongooseModule.forRoot('mongodb://127.0.0.1/nestjs_tutorial'), UsersModule, PostsModule],
  controllers: [],
  providers: [],
})
export class AppModule {}

post.module.ts

import { Module } from '@nestjs/common';
import { MongooseModule } from '@nestjs/mongoose';
import { Post, PostSchema } from 'src/schemas/Post.schema';
import { PostsController } from './posts.controller';
import { PostsService } from './posts.service';
import { User } from 'src/schemas/User.schema';

@Module({
  imports: [
    MongooseModule.forFeature([
      {
        name: Post.name,
        schema: PostSchema,
      }
    ]),
  ],
  controllers: [PostsController],
  providers: [PostsService],
})
export class PostsModule {}

post.controller.ts

import { Controller, Post, Body, UsePipes, ValidationPipe,} from '@nestjs/common';
import { CreatePostDto } from './dtos/CreatePost.dto';
import { PostsService } from './posts.service';

@Controller('posts')
export class PostsController {
  constructor(private postsService: PostsService) {}

  @Post()
  @UsePipes(new ValidationPipe())
  createPost(@Body() createPostDto: CreatePostDto) {
    return this.postsService.createPost(createPostDto);
  }
}

post.service.ts

import { Injectable } from '@nestjs/common';
import { InjectModel } from '@nestjs/mongoose';
import { Model } from 'mongoose';
import { Post } from 'src/schemas/Post.schema';
import { CreatePostDto } from './dtos/CreatePost.dto';

@Injectable()
export class PostsService {
  constructor(
    @InjectModel(Post.name) private postModel: Model<Post>) {}

  createPost( createPostDto: CreatePostDto) {
    const newPost = new this.postModel(createPostDto);
    return newPost.save();
  }
}

users.module.ts

import { Module } from '@nestjs/common';
import { MongooseModule } from '@nestjs/mongoose';
import { User, UserSchema } from 'src/schemas/User.schema';
import { UsersService } from './users.service';
import { UsersController } from './users.controller';
import {
  UserSettings,
  UserSettingsSchema,
} from 'src/schemas/UserSettings.schema';

@Module({
  imports: [
    MongooseModule.forFeature([
      {
        name: User.name,
        schema: UserSchema,
      },
      {
        name: UserSettings.name,
        schema: UserSettingsSchema,
      },
    ]),
  ],
  providers: [UsersService],
  controllers: [UsersController],
})
export class UsersModule {}

users.controller.ts

import { Controller, Post, Body, UsePipes, ValidationPipe, Get, Param, HttpException, Patch, Delete } from '@nestjs/common';
import { UsersService } from './users.service';
import { CreateUserDto } from './dto/CreateUser.dto';
import mongoose from 'mongoose';
import { UpdateUserDto } from './dto/UpdateUser.dto';

@Controller('users')
export class UsersController {
  constructor(private usersService: UsersService) {}

}

users.service.ts

import { Injectable } from '@nestjs/common';
import { InjectModel } from '@nestjs/mongoose';
import { Model } from 'mongoose';
import { User } from 'src/schemas/User.schema';
import { CreateUserDto } from './dto/CreateUser.dto';
import { UpdateUserDto } from './dto/UpdateUser.dto';
import { UserSettings } from 'src/schemas/UserSettings.schema';

@Injectable()
export class UsersService {
  constructor(
    @InjectModel(User.name) private userModel: Model<User>,
    @InjectModel(UserSettings.name)
    private userSettingsModel: Model<UserSettings>,
  ) {}
}

here is the error:

[12:55:42 pm] Found 0 errors. Watching for file changes.

[Nest] 13149 - 28/05/2024, 12:55:45 pm LOG [NestFactory] Starting Nest application... 
[Nest] 13149 - 28/05/2024, 12:55:45 pm LOG [InstanceLoader] AppModule dependencies initialized 
[Nest] 13149 - 28/05/2024, 12:55:45 pm LOG [InstanceLoader] MongooseModule dependencies initialized
[Nest] 13149 - 28/05/2024, 12:55:46 pm ERROR [ExceptionHandler] Nest can't resolve dependencies of the PostsService (?). Please make sure that the argument "PostModel" at index [0] is available in the PostsModule context.

Potential solutions:
- Is PostsModule a valid NestJS module?
- If "PostModel" is a provider, is it part of the current PostsModule?
- If "PostModel" is exported from a separate @Module, is that module imported within PostsModule? @Module({ imports: [ /* the Module containing "PostModel"*/ ] })

Error: Nest can't resolve dependencies of the PostsService (?). Please make sure that the argument "PostModel" at index [0] is available in the PostsModule context.

Potential solutions:
- Is PostsModule a valid NestJS module?
- If "PostModel" is a provider, is it part of the current PostsModule?
- If "PostModel" is exported from a separate @Module, is that module imported within PostsModule? @Module({ imports: [ /* the Module containing "PostModel"*/ ] })

I had no experience in nestjs. I get error when i added “PostsModule” in imports (shown below). I have tried removing mongooseModule and UsersModule from the imports, is still the same error.

@Module({
  imports: [
    MongooseModule.forRoot('mongodb://127.0.0.1/nestjs_tutorial'), UsersModule, PostsModule],
  controllers: [],
  providers: [],
})