JSFiddle - React, Tailwind, and code Playground

HTML

<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.10.2/jquery.min.js"></script>
<script src="https://maps.googleapis.com/maps/api/js?sensor=false"></script>
<div id="map"></div>
<div id="info"></div>

CSS

#map {
     height: 500px;
     width: 500px;
 }

JavaScript

var map;
var markers = {};
var bounds = null;
// add marker to object
var posi = new google.maps.LatLng(53.801279, -1.548567);
var name = 'Vince';
markers[name] = {};
markers[name].id = 1;
markers[name].lat = 53.801279;
markers[name].lng = -1.548567;
markers[name].state = 'Online';
markers[name].position = posi;
markers[name].selected = false;

$(document).ready(function () {

    var mapOptions = {
        zoom: 5,
        center: new google.maps.LatLng(53.801279, -1.548567),
        mapTypeId: google.maps.MapTypeId.ROADMAP
    };
    map = new google.maps.Map(document.getElementById('map'), mapOptions);
    var infowindow = new google.maps.InfoWindow();
    for (var key in markers) {
        var marker = new google.maps.Marker({
            position: new google.maps.LatLng(markers[key].lat, markers[key].lng),
            map: map
        });
        markers[key].marker = marker;

        google.maps.event.addListener(marker, 'click', (function (marker, key) {
            return function () {
                infowindow.setContent(key);
                infowindow.open(map, marker);
            }
        })(marker, key));
    }

    // Start drag rectangle to select markers !!!!!!!!!!!!!!!!
    var shiftPressed = false;

    $(window).keydown(function (evt) {
        if (evt.which === 16) { // shift
            shiftPressed = true;
            console.log("key down");
        }
    }).keyup(function (evt) {
        if (evt.which === 16) { // shift
            shiftPressed = false;
            console.log("key up ");
        }
    });

    var mouseDownPos, gribBoundingBox = null,
        mouseIsDown = 0;
    var themap = map;

    google.maps.event.addListener(themap, 'mousemove', function (e) {
       console.log("move md,sh", mouseIsDown,shiftPressed);        
        if (mouseIsDown && (shiftPressed|| gribBoundingBox != null) ) {
            if (gribBoundingBox !== null) // box exists
            {         
                var newbounds = new...