javascript - NestJS 从 ExceptionFilter 抛出

Question

我尝试使用 ExceptionFilter 将异常映射到对应的 HTTP。

这是我的代码:

@Catch(EntityNotFoundError)
export class EntityNotFoundFilter implements ExceptionFilter {
    catch(exception: EntityNotFoundError, _host: ArgumentsHost) {
        throw new NotFoundException(exception.message);
    }
}

但是，当过滤器代码被执行时，我得到了一个UnhandledPromiseRejectionWarning

 (node:3065) UnhandledPromiseRejectionWarning: Error: [object Object]
    at EntityNotFoundFilter.catch ([...]/errors.ts:32:15)
    at ExceptionsHandler.invokeCustomFilters ([...]/node_modules/@nestjs/core/exceptions/exceptions-handler.js:49:26)
     at ExceptionsHandler.next ([...]/node_modules/@nestjs/core/exceptions/exceptions-handler.js:13:18)
     at [...]/node_modules/@nestjs/core/router/router-proxy.js:12:35
     at <anonymous>
     at process._tickCallback (internal/process/next_tick.js:182:7)
 (node:3065) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). (rejection id: 5)

我该如何解决这个问题？

Answer 1

ExceptionFilter总是在发送响应之前被调用的最后一个地方，它负责构建响应。您不能从 ExceptionFilter 中重新抛出异常。

@Catch(EntityNotFoundError)
export class EntityNotFoundFilter implements ExceptionFilter {
  catch(exception: EntityNotFoundError, host: ArgumentsHost) {
    const response = host.switchToHttp().getResponse();
      response.status(404).json({ message: exception.message });
  }
}

---

或者，您可以创建一个 Interceptor改变你的错误:

@Injectable()
export class NotFoundInterceptor implements NestInterceptor {
  intercept(context: ExecutionContext, next: CallHandler): Observable<any> {
    // next.handle() is an Observable of the controller's result value
    return next.handle()
      .pipe(catchError(error => {
        if (error instanceof EntityNotFoundError) {
          throw new NotFoundException(error.message);
        } else {
          throw error;
        }
      }));
  }
}

在这个 codesandbox 中尝试一下.