JSFiddle - React, Tailwind, and code Playground

HTML

<link rel="stylesheet" href="http://openlayers.org/en/v3.13.1/css/ol.css">
<script src="http://openlayers.org/en/v3.13.1/build/ol.js"></script>
<div id="map" class="map"></div>

JavaScript

var raster = new ol.layer.Tile({
  source: new ol.source.MapQuest({layer: 'sat'})
});

var vector = new ol.layer.Vector({
  source: new ol.source.Vector({
    url: 'http://openlayers.org/en/master/examples/data/geojson/countries.geojson',
    format: new ol.format.GeoJSON()
  })
});

var map = new ol.Map({
  layers: [raster, vector],
  target: 'map',
  view: new ol.View({
    center: [0, 0],
    zoom: 2
  })
});

// debounce function from the 1st google result:
// https://davidwalsh.name/javascript-debounce-function
function debounce(func, wait, immediate) {
	var timeout;
	return function() {
		var context = this, args = arguments;
		var later = function() {
			timeout = null;
			if (!immediate) func.apply(context, args);
		};
		var callNow = immediate && !timeout;
		clearTimeout(timeout);
		timeout = setTimeout(later, wait);
		if (callNow) func.apply(context, args);
	};
};

var app = {};
app.DebounceSelect = function() {
  this.selectInteraction = new ol.interaction.Select({
    condition: ol.events.condition.pointerMove
  });

  var handleEventDebounce = debounce(function(evt) {
    return ol.interaction.Select.handleEvent.call(this.selectInteraction, evt);
  }.bind(this), 100);

  ol.interaction.Interaction.call(this, {
    handleEvent: function(evt) {
    	handleEventDebounce(evt);
      // always return true so that other interactions can
      // also process the event
      return true;
    }
  });
};
ol.inherits(app.DebounceSelect, ol.interaction.Interaction);

app.DebounceSelect.prototype.setMap = function(map) {
  this.selectInteraction.setMap(map);
};

var select = new app.DebounceSelect();
map.addInteraction(select);