How to use else condition in validationif decorator nestjs class-validator?

Issue

I need to conditional validate an input filed in nestjs, class-validator. There is a validateif decorator but how to add another validation in else section? For example: if first input was email use email decorator if it was phone match my regex.

    @IsNotEmpty()
    @IsEnum(UsernameType)
    public type: UsernameType;

// enum has two value: phone and email

    @IsNotEmpty()
    @ValidateIf(o => o.type === UsernameType.PHONE )
    @Matches(/(09)[0-9]{9}/)
    username: number;

    @IsNotEmpty()
    @ValidateIf(o => o.type === UsernameType.EMAIL)
    @IsEmail()
    username: string;
    

Solution

I resolved this issue with a Custom validation class which is available in class-validator.
Base on:
https://github.com/typestack/class-validator#custom-validation-classes.

Dto:

import { IsEmail, IsEnum, IsNotEmpty, Matches, Validate, ValidateIf } from "class-validator";
import { UsernameValidation } from "src/validations/username-validation";
import { UsernameType } from "../username-type.enum";

export class TypeDto {

    @IsNotEmpty()
    @IsEnum(UsernameType)
    public type: UsernameType;

    @Validate(UsernameValidation)
    @IsNotEmpty()
    username: string;
}

src/validations/username-validation:

import { TypeDto } from '../user/dto/type.dto';
import { UsernameType } from '../user/username-type.enum';
import { ValidatorConstraint, ValidatorConstraintInterface, ValidationArguments, Matches } from 'class-validator';

@ValidatorConstraint({ name: 'UsernameValidation', async: false })
export class UsernameValidation implements ValidatorConstraintInterface {
    validate(username: string, args: ValidationArguments) {

        if (JSON.parse(JSON.stringify(args.object)).type === UsernameType.PHONE) {


            var regexp = new RegExp('(09)[0-9]{9}');
            // "regexp" variable now validate iranian phone number.
            return regexp.test(username);
        } else {
            regexp = new RegExp("^[a-zA-Z0-9_.+-]+@[a-zA-Z0-9-]+\.[a-zA-Z0-9-.]+$");
            // "regexp" variable now validate email address.
            return regexp.test(username);
        }

    }

    defaultMessage(args: ValidationArguments) {

        if (JSON.parse(JSON.stringify(args.object)).type === UsernameType.PHONE) {
            return 'Enter a valid phone number.'
        } else {
            return 'Enter a valid email address.'
        }
    }
}

Answered By – mahmood morid

This Answer collected from stackoverflow, is licensed under cc by-sa 2.5 , cc by-sa 3.0 and cc by-sa 4.0