emvco-qr-sdk/dist/domain/value-objects/tag.js

A robust TypeScript SDK for decoding, validating, and processing EMVCo-compliant QR codes used in digital payment systems.

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.Tag = void 0;
/**
 * Represents a Tag value object in a TlvEntity structure.
 *
 * This class encapsulates the tag identifier ensuring that it complies with the expected format.
 * According to the EMVCo specifications, a valid Tag is typically a two-character string.
 */
class Tag {
    /**
     * Constructs a Tag value object.
     *
     * @param value - The tag string. It must be exactly two characters.
     * @throws {Error} If the tag is not exactly two characters.
     */
    constructor(value) {
        if (!Tag.isValid(value)) {
            throw new Error(`Invalid Tag: ${value}. A valid tag must be exactly 2 characters.`);
        }
        this._value = value;
    }
    /**
     * Returns the tag value as a string.
     *
     * @returns The tag as a string.
     */
    toString() {
        return this._value;
    }
    /**
     * Validates the provided tag value.
     *
     * @param value - The tag value to validate.
     * @returns True if the tag is exactly two characters, false otherwise.
     */
    static isValid(value) {
        return typeof value === 'string' && value.length === 2;
    }
}
exports.Tag = Tag;