happy-dom/src/nodes/element/NamedNodeMapProxyFactory.ts

Happy DOM is a JavaScript implementation of a web browser without its graphical user interface. It includes many web standards from WHATWG DOM and HTML.

/* eslint-disable filenames/match-exported */

import * as PropertySymbol from '../../PropertySymbol.js';
import NamedNodeMap from './NamedNodeMap.js';

/**
 * Named Node Map.
 *
 * @see https://developer.mozilla.org/en-US/docs/Web/API/NamedNodeMap
 */
export default class NamedNodeMapProxyFactory {
	/**
	 * Constructor.
	 *
	 * @param namedNodeMap
	 */
	public static createProxy(namedNodeMap: NamedNodeMap): NamedNodeMap {
		const namedItems = namedNodeMap[PropertySymbol.namedItems];
		const namespaceItems = namedNodeMap[PropertySymbol.namespaceItems];

		return new Proxy<NamedNodeMap>(namedNodeMap, {
			get: (target, property) => {
				if (property === 'length') {
					return namespaceItems.size;
				}
				if (property in target || typeof property === 'symbol') {
					return target[property];
				}
				const index = Number(property);
				if (!isNaN(index)) {
					return Array.from(namespaceItems.values())[index];
				}
				return target.getNamedItem(<string>property) || undefined;
			},
			set(target, property, newValue): boolean {
				if (typeof property === 'symbol') {
					target[property] = newValue;
					return true;
				}
				const index = Number(property);
				if (isNaN(index)) {
					target[property] = newValue;
				}
				return true;
			},
			deleteProperty(target, property): boolean {
				if (typeof property === 'symbol') {
					delete target[property];
					return true;
				}
				const index = Number(property);
				if (isNaN(index)) {
					delete target[property];
				}
				return true;
			},
			ownKeys(): string[] {
				const keys = Array.from(namedItems.keys());
				for (let i = 0, max = namespaceItems.size; i < max; i++) {
					keys.push(String(i));
				}
				return keys;
			},
			has(target, property): boolean {
				if (typeof property === 'symbol') {
					return false;
				}

				if (property in target || namedItems.has(property)) {
					return true;
				}

				const index = Number(property);

				if (!isNaN(index) && index >= 0 && index < namespaceItems.size) {
					return true;
				}

				return false;
			},
			defineProperty(target, property, descriptor): boolean {
				if (property in target) {
					Object.defineProperty(target, property, descriptor);
					return true;
				}

				return false;
			},
			getOwnPropertyDescriptor(target, property): PropertyDescriptor {
				if (property in target || typeof property === 'symbol') {
					return;
				}

				const index = Number(property);

				if (!isNaN(index) && index >= 0 && index < namespaceItems.size) {
					return {
						value: Array.from(namespaceItems.values())[index],
						writable: false,
						enumerable: true,
						configurable: true
					};
				}

				const namedItem = target.getNamedItem(<string>property);

				if (namedItem) {
					return {
						value: namedItem,
						writable: false,
						enumerable: true,
						configurable: true
					};
				}
			}
		});
	}
}