diff --git a/src/static/js/timeslider.js b/src/static/js/timeslider.js
index a3d8a462b..f171ead99 100644
--- a/src/static/js/timeslider.js
+++ b/src/static/js/timeslider.js
@@ -1,3 +1,5 @@
+'use strict';
+
 /**
  * This code is mostly from the old Etherpad. Please help us to comment this code.
  * This helps other people to understand this code better and helps them to improve it.
@@ -28,12 +30,12 @@ const Cookies = require('./pad_utils').Cookies;
 const randomString = require('./pad_utils').randomString;
 const hooks = require('./pluginfw/hooks');
 
-let token, padId, export_links;
+let token, padId, exportLinks, socket, changesetLoader, BroadcastSlider;
 
-function init() {
+const init = () => {
   $(document).ready(() => {
     // start the custom js
-    if (typeof customStart === 'function') customStart();
+    if (typeof customStart === 'function') customStart(); // eslint-disable-line no-undef
 
     // get the padId out of the url
     const urlParts = document.location.pathname.split('/');
@@ -51,7 +53,7 @@ function init() {
 
     const loc = document.location;
     // get the correct port
-    const port = loc.port == '' ? (loc.protocol == 'https:' ? 443 : 80) : loc.port;
+    const port = loc.port === '' ? (loc.protocol === 'https:' ? 443 : 80) : loc.port;
     // create the url
     const url = `${loc.protocol}//${loc.hostname}:${port}/`;
     // find out in which subfolder we are
@@ -71,7 +73,7 @@ function init() {
 
     // route the incoming messages
     socket.on('message', (message) => {
-      if (message.type == 'CLIENT_VARS') {
+      if (message.type === 'CLIENT_VARS') {
         handleClientVars(message);
       } else if (message.accessStatus) {
         $('body').html('<h2>You have no permission to access this pad</h2>');
@@ -81,7 +83,7 @@ function init() {
     });
 
     // get all the export links
-    export_links = $('#export > .exportlink');
+    exportLinks = $('#export > .exportlink');
 
     $('button#forcereconnect').click(() => {
       window.location.reload();
@@ -92,10 +94,10 @@ function init() {
 
     hooks.aCallAll('postTimesliderInit');
   });
-}
+};
 
 // sends a message over the socket
-function sendSocketMsg(type, data) {
+const sendSocketMsg = (type, data) => {
   socket.json.send({
     component: 'pad', // FIXME: Remove this stupidity!
     type,
@@ -105,19 +107,21 @@ function sendSocketMsg(type, data) {
     sessionID: Cookies.get('sessionID'),
     protocolVersion: 2,
   });
-}
+};
 
 const fireWhenAllScriptsAreLoaded = [];
 
-let changesetLoader;
-function handleClientVars(message) {
+const handleClientVars = (message) => {
   // save the client Vars
-  clientVars = message.data;
+  window.clientVars = message.data;
 
   // load all script that doesn't work without the clientVars
-  BroadcastSlider = require('./broadcast_slider').loadBroadcastSliderJS(fireWhenAllScriptsAreLoaded);
+  BroadcastSlider = require('./broadcast_slider')
+      .loadBroadcastSliderJS(fireWhenAllScriptsAreLoaded);
+
   require('./broadcast_revisions').loadBroadcastRevisionsJS();
-  changesetLoader = require('./broadcast').loadBroadcastJS(socket, sendSocketMsg, fireWhenAllScriptsAreLoaded, BroadcastSlider);
+  changesetLoader = require('./broadcast')
+      .loadBroadcastJS(socket, sendSocketMsg, fireWhenAllScriptsAreLoaded, BroadcastSlider);
 
   // initialize export ui
   require('./pad_impexp').padimpexp.init();
@@ -127,8 +131,8 @@ function handleClientVars(message) {
 
   // change export urls when the slider moves
   BroadcastSlider.onSlider((revno) => {
-    // export_links is a jQuery Array, so .each is allowed.
-    export_links.each(function () {
+    // exportLinks is a jQuery Array, so .each is allowed.
+    exportLinks.each(function () {
       // Modified from regular expression to fix:
       // https://github.com/ether/etherpad-lite/issues/4071
       // Where a padId that was numeric would create the wrong export link
@@ -156,7 +160,7 @@ function handleClientVars(message) {
   $('#viewfontmenu').change(function () {
     $('#innerdocbody').css('font-family', $(this).val() || '');
   });
-}
+};
 
 exports.baseURL = '';
 exports.init = init;