Logging exceptions in NestJS - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to import the Logger from NestJS.

NestJS

import { [1] } from '@nestjs/common';

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

AConsole

BLogger

CLogManager

DLogService

Attempts:

3 left

💡 Hint

Common Mistakes

Using a non-existent import like LogService or LogManager.

Trying to import Console which is not from NestJS.

The Logger class is imported from '@nestjs/common' to enable logging in NestJS.

2fill in blank

medium

Complete the code to create a Logger instance inside a service class.

NestJS

private readonly logger = new [1](MyService.name);

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ALogger

BLogManager

CLogService

DConsole

Attempts:

3 left

💡 Hint

Common Mistakes

Using Console instead of Logger.

Trying to instantiate a non-existent LogService.

The Logger class is instantiated with the class name to tag logs properly.

3fill in blank

hard

Fix the error in logging an exception message inside a catch block.

NestJS

catch (error) {
  this.logger.[1]('Error occurred:', error.message);
}

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Aerror

Blog

Cwarn

Dinfo

Attempts:

3 left

💡 Hint

Common Mistakes

Using log or info which are lower severity levels.

Using warn which is for warnings, not errors.

The error method logs error-level messages including exceptions.

4fill in blank

hard

Fill both blanks to log the stack trace of an exception.

NestJS

catch (error) {
  this.logger.[1]('Exception stack:', error.[2]);
}

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Aerror

Bstack

Cmessage

Dlog

Attempts:

3 left

💡 Hint

Common Mistakes

Logging error.message instead of error.stack for full trace.

Using log or warn instead of error method.

Use error to log the message and stack to show the full stack trace of the exception.

5fill in blank

hard

Fill all three blanks to create a custom exception filter that logs exceptions.

NestJS

import { ExceptionFilter, Catch, ArgumentsHost, [1] } from '@nestjs/common';

@Catch()
export class AllExceptionsFilter implements ExceptionFilter {
  private readonly logger = new [2](AllExceptionsFilter.name);

  catch(exception: any, host: [3]) {
    this.logger.error('Exception caught:', exception.stack);
    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'

ALogger

CArgumentsHost

DHttpException

Attempts:

3 left

💡 Hint

Common Mistakes

Importing HttpException instead of ArgumentsHost.

Using different names for Logger import and instance.

Wrong type for host parameter.

Import Logger and ArgumentsHost from '@nestjs/common'. Instantiate Logger for logging. Use ArgumentsHost type for the host parameter.