NestJs - How to get request body on interceptors

Question

I need to get the request body on my interceptor, before it goes to my controller:

import { Injectable, NestInterceptor, ExecutionContext, HttpException, HttpStatus } from '@nestjs/common';
import { Observable } from 'rxjs';
import { map } from 'rxjs/operators';

@Injectable()
export class ExcludeNullInterceptor implements NestInterceptor {
    intercept(context: ExecutionContext, call$: Observable<any>): Observable<any> {
        // How can I get the request body here?
        // Need to be BEFORE the Controller exec
    }
}

Answer 1

In your interceptor you can do:

async intercept(context: ExecutionContext, stream$: Observable<any>): Observable<any> {
    const body = context.switchToHttp().getRequest().body;
    // e.g. throw an exception if property is missing

Alternatively, you can use middleware where you directly have access to the request:

(req, res, next) => {