Custom exception classes in NestJS - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to import the base exception class from NestJS.

NestJS

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

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AHttpException

BController

CModule

DInjectable

Attempts:

3 left

💡 Hint

Common Mistakes

Importing unrelated decorators like Controller or Module.

Using Injectable instead of HttpException.

The HttpException class is the base for creating custom exceptions in NestJS.

2fill in blank

medium

Complete the code to define a custom exception class extending the base exception.

NestJS

export class CustomError extends [1] {
  constructor(message: string = 'Custom error occurred', status: number = 400) {
    super(message, status);
  }
}

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AController

BHttpException

CModule

DInjectable

Attempts:

3 left

💡 Hint

Common Mistakes

Extending decorators like Controller or Injectable.

Not extending any class.

Custom exceptions extend HttpException to inherit HTTP error behavior.

3fill in blank

hard

Fix the error in the constructor to correctly call the base class constructor with message and status.

NestJS

constructor() {
  super([1], 404);
}

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A'Error occurred'

B404

Cthis.message

D'Not Found Error'

Attempts:

3 left

💡 Hint

Common Mistakes

Passing the status code as the first argument.

Using this.message before calling super.

The first argument to super should be the error message string.

4fill in blank

hard

Fill both blanks to throw the custom exception with a message and status code.

NestJS

throw new CustomError([1], [2]);

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A'Resource missing'

B404

C500

D'Internal error'

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing message and status code order.

Using wrong status codes for the message.

The custom exception is thrown with a message and a matching HTTP status code.

5fill in blank

hard

Fill all three blanks to create a custom exception class with a dynamic message and status code.

NestJS

export class [1] extends HttpException {
  constructor(message: string, status: number) {
    super(message, [2]);
    this.[3] = message;
  }
}

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ADynamicError

Bstatus

Cmessage

DCustomException

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong property names.

Not passing status code correctly.

The class name is DynamicError. The constructor passes status to super. The instance property message is set to the passed message.