fake fo Promise.all

all.js

var all = (array) => {
	return new Promise((resolve, reject) => {
		var length = array.length;
		var collect = [];
		array.forEach((cur, index) => {
			cur
				.then(
					(value) => {
						collect[index] = value;
						if (0 === --length) resolve(collect);
					},
					(error) => {
						reject(error);
					}
				);
		});
	});
};