Use const in more places

src/ol/source/Raster.js

@@ -136,15 +136,15 @@ function createMinion(operation) {
  */
 function createWorker(config, onMessage) {
   const lib = Object.keys(config.lib || {}).map(function (name) {
-    return 'var ' + name + ' = ' + config.lib[name].toString() + ';';
+    return 'const ' + name + ' = ' + config.lib[name].toString() + ';';
   });
 
   const lines = lib.concat([
-    'var __minion__ = (' + createMinion.toString() + ')(',
+    'const __minion__ = (' + createMinion.toString() + ')(',
     config.operation.toString(),
     ');',
     'self.addEventListener("message", function(event) {',
-    '  var buffer = __minion__(event.data);',
+    '  const buffer = __minion__(event.data);',
     '  self.postMessage({buffer: buffer, meta: event.data.meta}, [buffer]);',
     '});',
   ]);

src/ol/source/Vector.js

@@ -90,24 +90,24 @@ export class VectorSourceEvent extends Event {
  * import {GeoJSON} from 'ol/format';
  * import {bbox} from 'ol/loadingstrategy';
  *
- * var vectorSource = new Vector({
+ * const vectorSource = new Vector({
  *   format: new GeoJSON(),
  *   loader: function(extent, resolution, projection, success, failure) {
- *      var proj = projection.getCode();
- *      var url = 'https://ahocevar.com/geoserver/wfs?service=WFS&' +
+ *      const proj = projection.getCode();
+ *      const url = 'https://ahocevar.com/geoserver/wfs?service=WFS&' +
  *          'version=1.1.0&request=GetFeature&typename=osm:water_areas&' +
  *          'outputFormat=application/json&srsname=' + proj + '&' +
  *          'bbox=' + extent.join(',') + ',' + proj;
- *      var xhr = new XMLHttpRequest();
+ *      const xhr = new XMLHttpRequest();
  *      xhr.open('GET', url);
- *      var onError = function() {
+ *      const onError = function() {
  *        vectorSource.removeLoadedExtent(extent);
  *        failure();
  *      }
  *      xhr.onerror = onError;
  *      xhr.onload = function() {
  *        if (xhr.status == 200) {
- *          var features = vectorSource.getFormat().readFeatures(xhr.responseText);
+ *          const features = vectorSource.getFormat().readFeatures(xhr.responseText);
  *          vectorSource.addFeatures(features);
  *          success(features);
  *        } else {
@@ -116,7 +116,7 @@ export class VectorSourceEvent extends Event {
  *      }
  *      xhr.send();
  *    },
- *    strategy: bbox
+ *    strategy: bbox,
  *  });
  * ```
  * @property {boolean} [overlaps=true] This source may have overlapping geometries.