url-path.js

'use strict';

const {inspect} = require('util');

const readonly = value => ({
	configurable: true,
	value,
});

// Not to be considered a URL.
class URLPath extends URL {
	constructor(text) {
		if (text[0] !== '/' || text[1] === '/' || text[1] === '\\') {
			const error = new Error('Not a host-relative URL: ' + inspect(text));
			error.code = 'ERR_INVALID_URL';
			throw error;
		}

		super(text, 'http://localhost/');
	}

	static tryCreate(text) {
		try {
			return new this(text);
		} catch (error) {
			if (error.code === 'ERR_INVALID_URL') {
				return null;
			}

			throw error;
		}
	}
}

['href', 'origin', 'protocol', 'username', 'password', 'host', 'hostname', 'port']
	.forEach(name => {
		Object.defineProperty(URLPath.prototype, name, readonly(undefined));
	});

['pathname', 'search', 'hash']
	.forEach(name => {
		Object.defineProperty(URLPath.prototype, name, {
			...Object.getOwnPropertyDescriptor(URL.prototype, name),
			set: undefined,
		});
	});

module.exports = URLPath;