decoval/lib/dv/dv-array.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 DvArray(options = {}) {
    const { minLength = { value: 0, message: "The array must contain at least {minLength.value} elements." }, maxLength = { value: Infinity, message: "The array must contain at most {maxLength.value} elements." }, elementsType = { value: "any", message: "The array elements must be of type {elementsType.value}." }, allowedValues = {
        value: [],
        message: "The array elements must be one of the allowed values: {allowedValues.value.join(', ')}.",
    }, message = "The array contains invalid elements.", } = options;
    const interpolateMessage = (message, data) => {
        return message.replace(/{([^}]+)}/g, (_, key) => data[key] || "");
    };
    return function (target, propertyKey) {
        const alreadyApplied = Reflect.getMetadata("valarray:applied", target, propertyKey);
        if (alreadyApplied) {
            throw new Error(`The @ValArray decorator has already been applied to the field "${propertyKey}"`);
        }
        Reflect.defineMetadata("valarray:applied", true, target, propertyKey);
        registerValidation(target, propertyKey, (value) => {
            if (!Array.isArray(value)) {
                throw new ValidationError(interpolateMessage(`The field "${propertyKey}" must be an array.`, {}));
            }
            if (value.length < minLength.value) {
                throw new ValidationError(interpolateMessage(minLength.message, { minLength }));
            }
            if (value.length > maxLength.value) {
                throw new ValidationError(interpolateMessage(maxLength.message, { maxLength }));
            }
            if (elementsType.value !== "any") {
                for (const item of value) {
                    if (typeof item !== elementsType.value) {
                        throw new ValidationError(interpolateMessage(elementsType.message, { elementsType }));
                    }
                }
            }
            if (allowedValues.value.length > 0) {
                for (const item of value) {
                    if (!allowedValues.value.includes(item)) {
                        throw new ValidationError(interpolateMessage(allowedValues.message || message, { allowedValues }));
                    }
                }
            }
        });
    };
}