Swagger doesn't show _id from mongoose schema

Question

I trying to use swagger to get better helps with api request in my project. Everything is great but i have problem with displaying _id property from mongo document.

I don't know exactly how i can attach _id in my document model let swagger see it.

For example i have user document which looks like this

export class User extends Document {
  @ApiProperty({ description: 'The username of the user' })
  @Prop({ type: String, required: true })
  username: string;

  @ApiProperty({ description: 'The email of the user' })
  @Prop({ required: true })
  email: string;

  @ApiProperty({ description: 'The hashed password of the user' })
  @Prop({ required: true, min: 6 })
  password: string;

  @ApiProperty({ description: 'User roles' })
  @Prop({
    type: [{ type: String, enum: UserRole }],
    default: [UserRole.Customer],
  })
  role: string[];

  @ApiProperty({ description: 'User billing details' })
  @Prop({ type: BillingSchema, default: new Billing() })
  billing: Billing;

  @ApiProperty({ description: 'Information about user account status' })
  @Prop({ type: Boolean, default: false })
  isActive: boolean;

  @ApiProperty({ description: 'User activation token used to account activation' })
  @Prop({ type: String || null, default: null })
  activationToken: string | null;

  @ApiProperty({ description: 'User reset password token used to reset password' })
  @Prop({ type: String || null, default: null })
  resetPasswordToken: string | null;

  @ApiProperty({ description: 'List of user bought products', type: Product, isArray: true })
  @Prop([{ type: mongoose.Schema.Types.ObjectId, ref: 'Product' }])
  products: Product[];

  @ApiProperty({ description: 'Date of register' })
  @Prop({ type: Date })
  createdAt: Date;

  @ApiProperty({ description: 'Date of account last update' })
  @Prop({ type: Date })
  updatedAt: Date;
}

any my User schema in swagger looks like this:

User{
username*   [...]
email*  [...]
password*   [...]
role*   [...]
billing*    {...}
isActive*   [...]
activationToken*    [...]
resetPasswordToken* [...]
products*   [...]
createdAt*  [...]
updatedAt*  [...]
}

I'll be grateful for any tips or help with solving that issue.

Answer 1

1. If you using nestjs plugin with swagger cli

{
  "$schema": "https://json.schemastore.org/nest-cli",
  "collection": "@nestjs/schematics",
  "sourceRoot": "src",
  "compilerOptions": {
    "deleteOutDir": true,
    "plugins": [
      {
        "name": "@nestjs/swagger",
        "options": {
          "introspectComments": true,
          "dtoFileNameSuffix": [
            ".dto.ts",
            ".schema.ts"
          ]
        }
      }
    ]
  }
}

2. You can define a virtual prop "id" as string.

import { Prop, Schema, SchemaFactory } from '@nestjs/mongoose';
import { HydratedDocument } from 'mongoose';

export type AuthorDocument = HydratedDocument<Author>;

@Schema({
  toJSON: {
    versionKey: false,
    // this option will show id prop in your schema.
    virtuals: true,
  },
})
export class Author {
  id: string;
  /**
   * the author's fisrt name
   * @example Jone
   */
  @Prop({
    type: String,
    required: true,
  })
  first_name: string;

  /**
   * the author's birthday
   */
  @Prop({
    type: Date,
  })
  date_of_birth?: Date;
}

3. Exclude the id prop in your create dtos,you can use OmitType.

import { OmitType } from '@nestjs/swagger';
import { Author } from '../schemas/author.schema';

export class CreateAuthorDto extends OmitType(Author, ['id']) {
    
  /**
   * @example 2023-07-18
   */
  date_of_birth?: Date;
}

4. Use the schema type in your service.

import { Injectable } from '@nestjs/common';
import { CreateAuthorDto } from './dto/create-author.dto';
import { UpdateAuthorDto } from './dto/update-author.dto';
import { InjectModel } from '@nestjs/mongoose';
import { Author } from './schemas/author.schema';
import { Model } from 'mongoose';

@Injectable()
export class AuthorsService {
  constructor(
    @InjectModel(Author.name) private readonly authorModel: Model<Author>,
  ) {}

  async create(createAuthorDto: CreateAuthorDto): Promise<Author> {
    const author = new this.authorModel(createAuthorDto);
    return await author.save();
  }

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

}

5. Result.