[Solved] Identify the error in this custom pipe code:import { PipeTransform, Injectable } from... Identify the error in this custom pipe code:import { PipeTransform, Injectable } from '@nestjs/common'; | NestJS

NestJS - Pipes

Identify the error in this custom pipe code:

import { PipeTransform, Injectable } from '@nestjs/common';

@Injectable()
export class UppercasePipe implements PipeTransform {
  transform(value: string) {
    return value.toUpperCase;
  }
}

AMissing @Injectable decorator

Btransform method missing return type

CtoUpperCase is used without parentheses

DPipeTransform interface not implemented

Step-by-Step Solution

Solution:

Step 1: Check the transform method implementation
The method returns value.toUpperCase without parentheses, which is a reference to the function, not the result.
Step 2: Identify correct usage of toUpperCase
toUpperCase is a method and must be called with parentheses: value.toUpperCase()
Final Answer:
toUpperCase is used without parentheses -> Option C
Quick Check:
Method calls need () to execute [OK]

Quick Trick: Remember to call string methods with () [OK]

Common Mistakes:

Forgetting parentheses on method calls
Assuming decorators are missing when present
Ignoring interface implementation

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More NestJS Quizzes

Identify the error in this custom pipe code:

Step 1: Check the transform method implementation

Step 2: Identify correct usage of toUpperCase

Final Answer:

Quick Check:

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