@Min/@Max errors override @IsInt when value is NaN after transformation

[NavidulHoque]

When using class-transformer with class-validator in NestJS, and applying stopAtFirstError: true, the validation order can be unintuitive. Specifically, if a property is transformed into NaN (e.g., due to an undefined or missing value), the @min or @max decorators may throw an error before the @ISINT decorator, even though @ISINT is listed first.

Steps to Reproduce:

Define a DTO with @type(), @ISINT(), and @min() decorators:

import { Type } from 'class-transformer';
import { IsInt, Min } from 'class-validator';

export class PaginationDto {
@type(() => Number)
@ISINT({ message: 'Page must be an integer' })
@min(1, { message: 'Page must be at least 1' })
readonly page: number;
}

Send a request with an undefined or missing page property.

Apply stopAtFirstError: true in the ValidationPipe:

app.useGlobalPipes(
new ValidationPipe({
transform: true,
stopAtFirstError: true,
}),
);

Expected Behavior:

The validation should stop at the first error encountered. In this case, the first error should be from the @ISINT decorator, indicating that the value is not an integer.

Actual Behavior:

The validation stops at the @min decorator, which throws an error because NaN is not a valid number, overriding the @ISINT error.

Cause:

The @min and @max decorators internally call isNumber() from validator.js, which detects NaN and throws an error before the @ISINT decorator has a chance to validate.

Suggested Fix:

Ensure that the decorators respect the order in which they are applied and that stopAtFirstError functions as intended, stopping at the first decorator that fails validation.

[PewDieRes]

i have recreated this issue locally ,
I would like to start working on this
if anyone has any suggestions please do tell

i have added a check in min.js and max.js as
function min(num, min) {
// First check if the value is an integer, if not, let IsInt handle the validation
if (typeof num !== 'number' || !Number.isInteger(num)) {
return true; // Let IsInt validator handle non-integer values
}
return typeof num === 'number' && typeof min === 'number' && num >= min;
}
and
function max(num, max) {
// First check if the value is an integer, if not, let IsInt handle the validation
if (typeof num !== 'number' || !Number.isInteger(num)) {
return true; // Let IsInt validator handle non-integer values
}
return typeof num === 'number' && typeof max === 'number' && num <= max;
}
this fixed the issue