Timeout Interceptor

import {
  Injectable,
  NestInterceptor,
  ExecutionContext,
  CallHandler,
  RequestTimeoutException,
  SetMetadata,
} from "@nestjs/common";
import { Observable, TimeoutError, throwError, timeout, catchError } from "rxjs";
import { Reflector } from "@nestjs/core";

export const TIMEOUT_KEY = "request_timeout";

/**
 * Set custom timeout for a route (in milliseconds).
 * 
 * Usage:
 * @Timeout(60000) // 60 seconds
 * @Post("upload")
 * upload() {}
 */

 
export const Timeout = (ms: number) => SetMetadata(TIMEOUT_KEY, ms);

@Injectable()
export class TimeoutInterceptor implements NestInterceptor {
  private readonly defaultTimeout: number;

  constructor(private reflector: Reflector) {
    this.defaultTimeout = parseInt(process.env.REQUEST_TIMEOUT || "30000", 10);
  }

  intercept(context: ExecutionContext, next: CallHandler): Observable<any> {
    const timeoutValue =
      this.reflector.getAllAndOverride<number>(TIMEOUT_KEY, [
        context.getHandler(),
        context.getClass(),
      ]) || this.defaultTimeout;

    return next.handle().pipe(
      timeout(timeoutValue),
      catchError((err) => {
        if (err instanceof TimeoutError) {
          const request = context.switchToHttp().getRequest();
          return throwError(
            () =>
              new RequestTimeoutException(
                `Request to ${request.method} ${request.url} timed out after ${timeoutValue}ms`
              )
          );
        }
        return throwError(() => err);
      })
    );
  }
}