Adjusting how errors are logged

This should allow for working out any JS failures that may occur

src/js/main.js

@@ -3,7 +3,20 @@ import Regexper from './regexper.js';
 import Parser from './parser/javascript.js';
 import _ from 'lodash';
 
+window._gaq = (typeof _gaq !== 'undefined') ? _gaq : {
+  push: console.debug.bind(console)
+};
+
 (function() {
+  window.addEventListener('error', function(error) {
+    _gaq.push([
+      '_trackEvent',
+      'global',
+      'exception',
+      `${error.filename}(${error.lineno}): ${error.message}`
+    ]);
+  });
+
   if (document.body.querySelector('#content .application')) {
     var regexper = new Regexper(document.body);
 

src/js/regexper.js

@@ -15,8 +15,6 @@ export default class Regexper {
     this.percentage = root.querySelector('#progress div');
     this.svgContainer = root.querySelector('#regexp-render');
     this.svgBase = this.root.querySelector('#svg-base').innerHTML;
-
-    this.gaq = (typeof window._gaq === 'undefined') ? [] : window._gaq;
   }
 
   keypressListener(event) {
@@ -79,7 +77,7 @@ export default class Regexper {
   }
 
   _trackEvent(category, action) {
-    this.gaq.push(['_trackEvent', category, action]);
+    window._gaq.push(['_trackEvent', category, action]);
   }
 
   set state(state) {
@@ -169,8 +167,9 @@ export default class Regexper {
         if (message === 'Render cancelled') {
           this._trackEvent('visualization', 'cancelled');
           this.state = '';
+        } else if (message.parseError) {
+          this._trackEvent('visualization', 'parse error');
         } else {
-          this._trackEvent('visualization', (message.parseError ? 'parse error' : 'exception'));
           throw message;
         }
       })