Exported MS Edge polyfill

src/TextAnnotator.jsx

@@ -4,8 +4,9 @@ import Highlighter from './highlighter/Highlighter';
 import SelectionHandler from './selection/SelectionHandler';
 import RelationsLayer from './relations/RelationsLayer';
 import RelationEditor from './relations/editor/RelationEditor';
+import { addPolyfills } from './utils/MSEdgePolyfills';
 
-import './utils/MSEdgePolyfills';
+addPolyfills(); // For Microsoft Edge
 
 /**
  * Pulls the strings between the annotation highlight layer

src/utils/MSEdgePolyfills.js

@@ -1,16 +1,20 @@
-if (!Element.prototype.matches) {
+export const addPolyfills = () => {
-  Element.prototype.matches = Element.prototype.msMatchesSelector ||
-    Element.prototype.webkitMatchesSelector;
-}
 
-if (!Element.prototype.closest) {
+  if (!Element.prototype.matches) {
-  Element.prototype.closest = function(s) {
+    Element.prototype.matches = Element.prototype.msMatchesSelector ||
-    let el = this;
+      Element.prototype.webkitMatchesSelector;
+  }
+
+  if (!Element.prototype.closest) {
+    Element.prototype.closest = function(s) {
+      let el = this;
+
+      do {
+        if (Element.prototype.matches.call(el, s)) return el;
+        el = el.parentElement || el.parentNode;
+      } while (el !== null && el.nodeType === 1);
+      return null;
+    };
+  }
 
-    do {
-      if (Element.prototype.matches.call(el, s)) return el;
-      el = el.parentElement || el.parentNode;
-    } while (el !== null && el.nodeType === 1);
-    return null;
-  };
 }