decoval/lib/dv/dv-custom.js

DecoVal is a decorator-driven validation pattern that allows you to add validation rules directly to the properties of TypeScript classes, simplifying data control and increasing code readability and reusability.

import { ValidationError } from "./error/validation.error";
import { registerValidation } from "./register.validation";
export function DvCustom(rules) {
    if (!rules || (Array.isArray(rules) && rules.length === 0)) {
        throw new Error("The 'rules' parameter of the @DvCustom decorator cannot be empty or undefined.");
    }
    const ruleList = Array.isArray(rules) ? rules : [rules];
    for (const rule of ruleList) {
        if (typeof rule !== "object" || rule === null) {
            throw new Error("Each custom rule must be a valid object.");
        }
        if (typeof rule.validate !== "function") {
            throw new Error("The 'validate' property of each rule must be a function.");
        }
        if (typeof rule.message !== "string" || rule.message.trim() === "") {
            throw new Error("The 'message' property of each rule must be a non-empty string.");
        }
    }
    return function (target, propertyKey) {
        var _a;
        const appliedDecorators = (_a = Reflect.getMetadata("valtcustom:applied", target, propertyKey)) !== null && _a !== void 0 ? _a : new Set();
        if (appliedDecorators.has("DvCustom")) {
            throw new Error(`The @DvCustom decorator has already been applied in the field "${propertyKey}".`);
        }
        appliedDecorators.add("DvCustom");
        Reflect.defineMetadata("valcustom:applied", appliedDecorators, target, propertyKey);
        registerValidation(target, propertyKey, (value) => {
            for (const rule of ruleList) {
                const isValid = rule.validate(value);
                if (!isValid) {
                    throw new ValidationError(`[${propertyKey}] ${rule.message}`);
                }
            }
        });
    };
}