I'm using an interceptor to transform my response. I want to set the HttpStatus inside but the code I'm using now doesn't work.

import CallHandler, ExecutionContext, NestInterceptor, SetMetadata from '@nestjs/common';
import Observable from 'rxjs';
import map from 'rxjs/operators';
import classToPlain from 'class-transformer';
import ApiResponse from '../models/apiResponse';

export class TransformInterceptor implements NestInterceptor any>,
 ): Observable<ApiResponse 

Updated Answer

Since nest version 6.1.0, it is possible to set the status code in an interceptor; it will not be overwritten anymore (see this PR):

context.switchToHttp()
 .getResponse()
 .status(205);

Outdated Answer

Setting the status code from an Interceptor is impossible (see this issue) because:

• sometimes response status codes are dependent on exceptions and exception filters are executed after interceptors,


• global response controller's logic is the last step performed just before sending a final result through the network (that's the place
  where default status codes come in).

So your status code will be overridden by the default code 200/201 or an exception filter.

As a (hacky) workaround, you can use exception filters to set the status code in interceptors:

1) Create your own exception as a wrapper around HttpException:

export class StatusException extends HttpException 
 constructor(data, status: HttpStatus) 
 super(data, status);
 

2) Create an exception filter that sets the response code and returns the data:

@Catch(StatusException)
export class StatusFilter implements ExceptionFilter 
 catch(exception: StatusException, host: ArgumentsHost) 
 const ctx = host.switchToHttp();
 const response = ctx.getResponse<Response>();
 const status = exception.getStatus();
 console.log(`Setting status to $status`);
 response.status(status).json(exception.message);
 

3) Instead of setting the response throw the according exception in your interceptor:

@Injectable()
export class StatusInterceptor implements NestInterceptor 
 intercept(context: ExecutionContext, next): Observable<any> 
 return next.handle().pipe(
 map((data: any) => 
 if (data.text === 'created') 
 throw new StatusException(data, HttpStatus.CREATED);
 else 
 throw new StatusException(data, HttpStatus.ACCEPTED);
 
 ),
 );
 

4) Use it in your controller:

@UseFilters(StatusFilter)
@UseInterceptors(StatusInterceptor)
@Controller()
export class AppController 
 @Get(':param')
 async get(@Param('param') param) 
 return text: param ;
 

Alternatively, you can inject @Res() in your controller and directly control the response code (but also losing interceptors, exception filters, etc.)