BadRequestException 400 getting returned to client as a 500 error

Bug Report

Current behavior

I have an endpoint that is returning 500 when it should be returning 400. The controller associated with this endpoint is throwing a BadRequestException, but when it bubbles up to the global Nest error handling mechanism it is not being recognized as an instance or subclass of HttpException. Therefore, Nest is returning a default of 500 to the client.

import { isoToDate } from 'shared-nest-logic';

@Controller('todos')
class TodosController {
  constructor(private readonly todoService: TodoService) {}

  @Get()
  async getTodos(
    @Query('start') start: string,
    @Query('end') end: string
  ) {
    // isoToDate comes from a library that contains shared logic
    // for several different Nest apps. This library lists
    // @nestjs/core and @nestjs/common as dependencies.
    // When a required query parameter is missing, isToDate will
    // throw a NestJS BadRequestException.

    const [startDate, endDate] = [isoToDate(start), isoToDate(end)];
    const todos: Todo[] = this.todoService.getTodos(startDate, endDate);
    return todos;
  }
}

Expected behavior

I would expect Nest to recognize the BadRequestException as a valid instance of HttpException and return 400 to the client, rather than the fallback error of 500.

Environment

Application:
  @nestjs/common: 7.3.2
  @nestjs/core: 7.3.2

Library:
  @nestjs/common: 7.3.2
  @nestjs/core: 7.3.2
 
- Node: 10.16.3
- NPM: 6.9.0

[jmcdo29]

@v1d3rm3 without a reproduction I can’t tell you what’s wrong. What Kamil said it’s the correct approach. If you’re working with this locally, you’ll need to move the built library to the node_modules rather than using something like npm link due to Typescript’s class instanceof resolution

[kamilmysliwiec]

// isoToDate comes from a library that contains shared logic // for several different Nest apps. This library lists // @nestjs/core and @nestjs/common as dependencies.

Shared libraries should list @nestjs/core and @nestjs/common as peerDependencies. Otherwise, httpException instanceof HttpException in which httpException is thrown from shared library will give false value.