Calling REST API with ES6 Proxies

api-proxy.js

var EndPoint = function (baseUrl) {
    
    var request = function (type, url) {
        
        return new Promise(function (resolve, reject) {
            
            var xhr = new XMLHttpRequest();
            xhr.open(type, url);
            xhr.setRequestHeader('Content-Type', 'application/json');
            xhr.responseType =  'json';
            xhr.onload = function() {
                
                if (xhr.status === 200) {
                    resolve(xhr.response);
                } else {
                    reject(xhr.status);
                }
            };
        });
    };
    
    return new Proxy({}, {
        get (target, prop, receiver) {
            return request(baseUrl + '/' + prop);
        }
    });
};