How can I return a non empty response using Nest JS api and postman - node.js

Question

I am using Nest Js to setup my server. I tried to fetch data from Postman to test if the API urls work. However I find that I get empty response from the server or undefined value from the postman request. The below code is the users.controller.ts
import {
Body,
Controller,
Delete,
Get,
Header,
Param,
Post,
Put,
} from '#nestjs/common';
import { User } from './users.entity';
import { UsersService } from './users.service';
#Controller('users')
export class UsersController {
constructor(private usersService: UsersService) {}
/* #Get('/api/users')
index(): string {
return 'This will return user.';
} */
#Get()
index(): Promise<User[]> {
return this.usersService.findUsers();
}
#Post('create')
#Header('Content-Type', 'application/json')
async create(#Body() userData: User): Promise<any> {
console.log(userData.UserId, userData.UserType + ' Check if working');
return this.usersService.create(userData);
}
#Put(':userid/update')
async update(#Param('userid') userid, #Body() userData: User): Promise<any> {
userData.UserId = Number(userid);
console.log('Update #' + userData.UserId);
return this.usersService.update(userData);
}
#Delete(':userid/delete')
async delete(#Param('userid') userid): Promise<any> {
return this.usersService.delete(userid);
}
}
and this code is users.service.ts
import { Injectable } from '#nestjs/common';
import { InjectRepository } from '#nestjs/typeorm';
import { Repository } from 'typeorm';
import { User } from './users.entity';
import { UpdateResult, DeleteResult } from 'typeorm';
#Injectable()
export class UsersService {
constructor(
#InjectRepository(User) private userRepository: Repository<User>,
) {}
async findUsers(): Promise<User[]> {
return await this.userRepository.find();
}
async create(user: User): Promise<User> {
console.log(user.UserType + 'User type');
return await this.userRepository.save(user);
}
async update(user: User): Promise<UpdateResult> {
return await this.userRepository.update(user.UserId, user);
}
async delete(userid): Promise<DeleteResult> {
return await this.userRepository.delete(userid);
}
}
If you can see the post request, there is a console.log() to check whether there is a response or not. Hence I am getting an undefined value instead. I am seeking for support to understand where I am going wrong. I am not able to traceback the error as well.

Answer 1

Welcome!
You are not logging what your service returns, instead you are logging what your service receives as the body of the request:
#Post('create')
#Header('Content-Type', 'application/json')
async create(#Body() userData: User): Promise<any> {
// ##################################
// here, you are logging userData, which is the object your
// service receives as input
// ##################################
console.log(userData.UserId, userData.UserType + ' Check if working');
return this.usersService.create(userData);
}
If that console.log line is logging undefined, it means you are not sending the right data in your HTTP Post request body in postman.
You should be sending a User json object as the request payload.

Answer 2

Had the same problem and solved it by annotating my return object.
export class CriarTarefaDto {
public nome: string;
public ativo?: boolean;
}
This was my object that always returned me empty when checking the return of the #Body annotation. I fixed it by including class-validator lib annotations in my DTO properties.
import { IsBoolean, IsString } from 'class-validator';
export class CriarTarefaDto {
#IsString()
public nome: string;
#IsBoolean()
public ativo?: boolean;
}
In your DTO object you need to use some annotation or extend the DTO with classes that register its properties.