is-implemented.js #1

'use strict';

module.exports = function () {
	var set, iterator, result;
	if (typeof Set !== 'function') return false;
	set = new Set(['raz', 'dwa', 'trzy']);
	if (String(set) !== '[object Set]') return false;
	if (set.size !== 3) return false;
	if (typeof set.add !== 'function') return false;
	if (typeof set.clear !== 'function') return false;
	if (typeof set.delete !== 'function') return false;
	if (typeof set.entries !== 'function') return false;
	if (typeof set.forEach !== 'function') return false;
	if (typeof set.has !== 'function') return false;
	if (typeof set.keys !== 'function') return false;
	if (typeof set.values !== 'function') return false;

	iterator = set.values();
	result = iterator.next();
	if (result.done !== false) return false;
	if (result.value !== 'raz') return false;

	return true;
};