Unlock the full potential of data validation in your NestJS applications by learning how to create custom decorators! In this detailed tutorial, we delve into the power of the class-validator library and show you how to craft a versatile IsNumber decorator. This custom decorator not only checks if a value is a number but also lets you specify minimum and maximum values for enhanced data integrity.
import { applyDecorators } from '@nestjs/common';
import { IsNumber as IsNumberBase, Min, Max } from 'class-validator';
import { DEFAULT_MIN, DEFAULT_MAX } from '../constants/number-fields.constants';
type TIsNumberOptions = {
min?: number;
max?: number;
};
export default function IsNumber(options?: TIsNumberOptions) {
const { min = DEFAULT_MIN, max = DEFAULT_MAX } = options || {};
return applyDecorators(IsNumberBase(), Min(min), Max(max));
}