zod numeric string to number

zStringToNumber.ts

import { z } from "zod";

export function zStringToNumber() {
    return z.preprocess((a) => {
        const stringRes = z.string().safeParse(a);
        if (!stringRes.success) {
            return a;
        }

        const numberRes = Number.parseInt(stringRes.data);
        if (Number.isNaN(numberRes)) {
            return a;
        }

        return numberRes;
    }, z.number());
}