https://github.com/lukasjhan/nestjs-exception-factory

Simple Factory Function for Nestjs Exception
https://github.com/lukasjhan/nestjs-exception-factory

exception javascript nestjs typescript

Last synced: 21 days ago
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Simple Factory Function for Nestjs Exception

• Host: GitHub
• URL: https://github.com/lukasjhan/nestjs-exception-factory
• Owner: lukasjhan
• Created: 2023-05-05T06:59:23.000Z (over 1 year ago)
• Default Branch: master
• Last Pushed: 2023-05-05T07:04:38.000Z (over 1 year ago)
• Last Synced: 2024-04-12T05:09:11.422Z (7 months ago)
• Topics: exception, javascript, nestjs, typescript
• Language: TypeScript
• Homepage:
• Size: 7.81 KB
• Stars: 0
• Watchers: 1
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md

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README

        
# NestJS Exception Factory

Simple Factory Function to create NestJS Exceptions.

## Code

```typescript

declare class CustomExceptionProtoType extends HttpException {

  constructor();

}

export function createException(

  status: HttpStatus,

  errorCode: string,

  message: string

) {

  class CustomException extends HttpException {

    constructor() {

      super({ status, errorCode, message }, status);

      Object.setPrototypeOf(this, Object.getPrototypeOf(HttpException));

    }

  }

  return CustomException as unknown as typeof CustomExceptionProtoType;

}

```

## Usage

Copy & Paste into your nestjs project. Then use it like this:

```typescript

export const CustomException = createException(

  HttpStatus.BAD_REQUEST,

  'CUSTOM_ERROR_CODE',

  'Custom Error Message'

);

function someFunction() {

  ...

  throw new CustomException();

  ...

}

```

## Warning

`Do not import this code as a module. `

`It will not work.`

Becasue behaviour of `instanceof` operator, is that the class must be exactly in the parent chain, in the sense of JavaScript object reference. Hence, if you import `HttpException` class twice, they are different actual object references, and instanceof may give a "false" negative.

In NestJS, checking exception type is done by `instanceof` operator. So, if you import this code as a module, it will not work.