subscriable request

subscribable-request.js

export default function subscribableRequest({ baseUrl }) {
	let subscriptions = {};
	return {
		fetch: ({ endpoint, ...rest }) => (
			fetch(`${baseUrl}/${endpoint}`, ...rest)
			.then(res => res.json())
			.then(res => {
				subscriptions[endpoint] && 
				subscriptions[endpoint].forEach(sub => sub(res));
				return res;
			});
		),
		subscribe({ endpoint, fn }) {
			subscriptions[endpoint] = (subscriptions[endpoint] || []).concat(fn);
			return function unsubscribe() {
				subscriptions = subscriptions.filter(sub => sub !== fn);
			}
		}	
	}
}