@Query() does not transform to DTO

Bug Report

Current behavior

I have a controller that needs to recive data from the request query and I want to put that data into a DTO using @Query() but it does not properly transform the DTO to the target interface

Input Code

import { Get, Controller, Query, Post, Body, UsePipes, ValidationPipe } from '@nestjs/common';

interface TestDto {
  field1: number;
  field2: boolean;
}

@Controller()
export class AppController {
  constructor() {}

  @Get()
  @UsePipes(new ValidationPipe({ whitelist: false, transform: true}))
  root(@Query() dto: TestDto): TestDto {
    return dto;
  }

}

Expected behavior

If I call http://localhost:3000/?field1=10&field2=true&field3=test I get

{
"field1": "10",
"field2": "true",
"field3": "test"
}

But the expected result is:

{
"field1":  10,
"field2": true
}

Environment

Nest version: 5.7.4
Node version: 10.9.0
class-transformer: 0.2.3
class-validator: 0.10.1
tsc version: 1.8.10
Platform: Ubuntu 18.10

[Hwan-seok]

Use @Type on your properties. @Query always return string type so we have to cast to desired type.

Example

import { Type } from 'class-transformer';

export class TestDto {
  @IsNumber()
  @Type(() => Number)
  field1: number;

  @IsBoolean()
  @Type(() => Boolean)
  field2: boolean;
}

[wintertime-inc]

Whitelist must be set as true in order to cut additionals.

https://docs.nestjs.com/techniques/validation#stripping-properties