intercept and manipulate ajax.js

const XHR = XMLHttpRequest;

unsafeWindow.XMLHttpRequest = new Proxy(XHR, {
    construct: (target, args) => {
        const listeners = [{
            regex: /close\/add/,
            get: data => {
                if(data.property === 'responseText') {
                    console.log(xhr.responseText);
                    const obj = JSON.parse(xhr.responseText);
                    if(!obj.Count) {
                        Object.assign(obj, {
                            "Message":"Your vote has been recorded",
                            "ResultChangedState":false,
                            "Count":4,
                            "CountNeededForStateChange":1
                        });
                    }
                    data.value = JSON.stringify(obj);
                }
                return data;
            }
        },
        /* For teh debug porpoises  
        {
            regex: /./,
            get: data => console.log(xhr.responseURL, 'get', data),
            set: data => console.log(xhr.responseURL, 'set', data),
            call: data => console.log(xhr.responseURL, 'call', data)
        }
        */
        ];
        
        const callall = (type, data) => (listeners.forEach(e => type in e && e.regex.test(xhr.responseURL) && Object.assign(data, e[type](data))), data);
        
        const xhr = new XHR();
        
        return new Proxy(xhr, {
            get: (t, k) => {
                if(typeof xhr[k] === 'function') {
                    return new Proxy(xhr[k], {
                        apply: async (target, self, args) => {
                            const result = await xhr[k](...args);
                            const data = callall('call', { 'method': k, 'args': args.join(', '), 'value': result });
                            return data.value;
                        }
                    });
                }
                const data = callall('get', { 'property': k, 'value': xhr[k] });
                return data.value;
            },
            set: (t, k, v) => {
                const data = callall('set', { 'property': k, 'value': v });
                xhr[k] = data.value;
                return true;
            }
        });
    }
});