Uncaught TypeError: can't access property

var websocket, ws = "link",
    player = document.createElement("audio");

function connect(e) {
    void 0 === websocket && ((websocket = new WebSocket(e)).onopen = function() {}, websocket.onmessage = function(e) {
        var o = JSON.parse(e.data);
        chrome.storage.local.get("title", function(e) {
            if(e.title !== o.now_playing.song.title) {
                if(!player.paused) o.now_playing.song.title, o.now_playing.song.artist;
                chrome.storage.local.set({
                    artwork: o.now_playing.song.art
                }), chrome.storage.local.set({
                    title: o.now_playing.song.title
                }), chrome.storage.local.set({
                    artist: o.now_playing.song.artist
                })
            }
        }), "" === player.src && (player.src = o.station.listen_url), chrome.runtime.sendMessage({
            message: "radio_fetched",
            data: o.now_playing.song
        })
    }, websocket.onclose = function() {
        websocket = void 0
    })
}

function closeWebSocketConnection() {
    null == websocket && null == websocket || (websocket.close(), websocket = void 0)
}

chrome.extension.onMessage.addEventListener(function(e) {
    "load" === e.action && (connect(ws), chrome.runtime.sendMessage({
        message: "player",
        data: {
            status: player.paused,
            volume: player.volume
        }
    })), "play" === e.action && (player.paused ? player.play() : (player.pause(), closeWebSocketConnection())), "volume" === e.action && (player.volume = e.data / 100)
});

window.onload = function(e) {
    chrome.storage.local.get("artwork", function(e) {
        void 0 !== e.artwork && (document.getElementById("artwork").src = e.artwork)
    }), chrome.storage.local.get("title", function(e) {
        void 0 !== e.title && (document.getElementById("title").innerHTML = e.title)
    }), chrome.storage.local.get("artist", function(e) {
        void 0 !== e.artist && (document.getElementById("artist").innerHTML = e.artist)
    }), chrome.extension.sendMessage({
        action: "load"
    }), document.getElementById("play").addEventListener("click", function() {
        e.preventDefault(), document.getElementById("play").classList.toggle("paused"), chrome.extension.sendMessage({
            action: "play"
        })
    }), document.getElementById("volume").addEventListener("change", function() {
        chrome.extension.sendMessage({
            action: "volume",
            data: this.value
        })
    })
}, chrome.runtime.onMessage.addListener(function(e, t, n) {
    "radio_fetched" === e.message && (document.getElementById("artwork").src = e.data.art, document.getElementById("title").innerHTML = e.data.title, document.getElementById("artist").innerHTML = e.data.artist), "player" === e.message && (!1 === e.data.status && document.getElementById("play").classList.add("paused"), document.getElementById("volume").value = 30 * e.data.volume)
});