Yet another browser AJAX lib

atena.js

(function () {
    function prmze() {
        let thenCallback = null;
        let catchCallback = null;
        let child = null;

        return {
            ready: false,
            then: function (callback) {
                this.ready = true;
                child = prmze();
                thenCallback = callback;
                return child;
            },
            catch: function (callback) {
                this.ready = true;
                child = prmze();
                catchCallback = callback;
                return child;
            },
            resolve: function (value) {
                thenCallback && thenCallback(value);
                child && child.resolve(value);
            },
            fail: function (value) {
                let cb = catchCallback;

                if (!cb && (!child || !child.ready))
                    cb = thenCallback;

                cb && cb(value);
                child && child.fail(value);
            }
        };
    }

    function request(method, url, data) {
        const response = prmze();

        const xhr = new XMLHttpRequest();
        xhr.open(method, url);
        xhr.addEventListener('load', (e) => {
            response.resolve(xhr);
        });
        xhr.addEventListener('error', (e) => {
            response.fail(xhr);
        });

        data ? xhr.send(data) : xhr.send();
        return response;
    }

    window.atena = {
        get: (url) => {
            return request('GET', url, null);
        },
        post: (url, data) => {
            return request('POST', url, data);
        },
        delete: (url) => {
            return request('DELETE', url, null);
        },
        head: (url) => {
            return request('HEAD', url, null);
        },
        put: (url, data) => {
            return request('PUT', url, data);
        },
        patch: (url, data) => {
            return request('PATCH', url, data);
        },
        options: (url) => {
            return request('OPTIONS', url, null);
        }
    };

})();