Global exception filters in NestJS - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create a global exception filter class in NestJS.

NestJS

import { ExceptionFilter, Catch, ArgumentsHost } from '@nestjs/common';

@Catch()
export class GlobalExceptionFilter implements [1] {
  catch(exception: any, host: ArgumentsHost) {
    const ctx = host.switchToHttp();
    const response = ctx.getResponse();
    response.status(500).json({ message: 'Internal server error' });
  }
}

Drag options to blanks, or click blank then click option'

AMiddleware

BPipeTransform

CInterceptor

DExceptionFilter

Attempts:

3 left

💡 Hint

Common Mistakes

Using PipeTransform or Interceptor instead of ExceptionFilter

Not implementing any interface

The class must implement the ExceptionFilter interface to act as an exception filter in NestJS.

2fill in blank

medium

Complete the code to apply the global exception filter in the main bootstrap function.

NestJS

import { NestFactory } from '@nestjs/core';
import { AppModule } from './app.module';
import { GlobalExceptionFilter } from './filters/global-exception.filter';

async function bootstrap() {
  const app = await NestFactory.create(AppModule);
  app.[1](new GlobalExceptionFilter());
  await app.listen(3000);
}
bootstrap();

Drag options to blanks, or click blank then click option'

AuseGlobalFilters

BuseGlobalPipes

CuseGlobalInterceptors

DuseMiddleware

Attempts:

3 left

💡 Hint

Common Mistakes

Using useGlobalPipes or useGlobalInterceptors instead

Trying to use useMiddleware which is not a method on the app instance

To apply a global exception filter, use the useGlobalFilters method on the app instance.

3fill in blank

hard

Fix the error in the global exception filter to correctly get the HTTP response object.

NestJS

catch(exception: any, host: ArgumentsHost) {
  const ctx = host.[1]();
  const response = ctx.getResponse();
  response.status(500).json({ message: 'Internal server error' });
}

Drag options to blanks, or click blank then click option'

AswitchToHttp

BswitchToRpc

CswitchToWs

DgetHttpContext

Attempts:

3 left

💡 Hint

Common Mistakes

Using switchToRpc or switchToWs which are for other contexts

Using a non-existent method like getHttpContext

To get the HTTP context from ArgumentsHost, use the switchToHttp() method.

4fill in blank

hard

Fill both blanks to create a global exception filter that returns the exception message and status code.

NestJS

catch(exception: any, host: ArgumentsHost) {
  const ctx = host.[1]();
  const response = ctx.getResponse();
  const status = exception.[2] || 500;
  response.status(status).json({
    statusCode: status,
    message: exception.message || 'Internal server error',
  });
}

Drag options to blanks, or click blank then click option'

AswitchToHttp

BgetStatus

Cstatus

DgetResponse

Attempts:

3 left

💡 Hint

Common Mistakes

Using getStatus() method which does not exist on exception

Using getResponse() instead of switchToHttp()

Use switchToHttp() to get the HTTP context and access the status property from the exception for the HTTP status code.

5fill in blank

hard

Fill all three blanks to create a global exception filter that logs the error and sends a JSON response with status and message.

NestJS

catch(exception: any, host: ArgumentsHost) {
  const ctx = host.[1]();
  const response = ctx.getResponse();
  const request = ctx.getRequest();
  const status = exception.[2] || 500;
  console.error('Error:', exception.message);
  response.status(status).json({
    statusCode: status,
    timestamp: new Date().toISOString(),
    path: request.[3],
    message: exception.message || 'Internal server error',
  });
}

Drag options to blanks, or click blank then click option'

AswitchToHttp

Bstatus

Curl

Dmessage

Attempts:

3 left

💡 Hint

Common Mistakes

Using getResponse() instead of switchToHttp()

Using message instead of status for HTTP status code

Using path instead of url for request path

Use switchToHttp() to get HTTP context, status property from exception for status code, and url property from request for the request path.