Bump govuk front end toolkit to 4.3.0

4.3.0
Allow javascript error tracking to be filtered to avoid noise from
plugins

https://github.com/alphagov/govuk_frontend_toolkit/blob/master/CHANGELOG
.md

govuk/public/javascripts/govuk/analytics/error-tracking.js

@@ -1,20 +1,40 @@
 // Extension to track errors using google analytics as a data store.
 (function() {
-
   "use strict";
-
   GOVUK.analyticsPlugins = GOVUK.analyticsPlugins || {};
 
-  GOVUK.analyticsPlugins.error = function () {
+  GOVUK.analyticsPlugins.error = function (options) {
+    var options = options || {},
+        filenameMustMatch = options.filenameMustMatch;
+
     var trackJavaScriptError = function (e) {
-      var errorSource = e.filename + ': ' + e.lineno;
-      GOVUK.analytics.trackEvent('JavaScript Error', e.message, {
-        label: errorSource,
-        value: 1,
-        nonInteraction: true
-      });
+      var errorFilename = e.filename,
+          errorSource = errorFilename + ': ' + e.lineno;
+
+      if (shouldTrackThisError(errorFilename)) {
+        GOVUK.analytics.trackEvent('JavaScript Error', e.message, {
+          label: errorSource,
+          value: 1,
+          nonInteraction: true
+        });
+      }
     };
 
+    function shouldTrackThisError(errorFilename) {
+      // Errors in page should always be tracked
+      // If there's no filename filter, everything is tracked
+      if (!errorFilename || !filenameMustMatch) {
+        return true;
+      }
+
+      // If there's a filter and the error matches it, track it
+      if (filenameMustMatch.test(errorFilename)) {
+        return true;
+      }
+
+      return false;
+    }
+
     if (window.addEventListener) {
       window.addEventListener('error', trackJavaScriptError, false);
     } else if (window.attachEvent) {
@@ -23,5 +43,4 @@
       window.onerror = trackJavaScriptError;
     }
   }
-
 }());

govuk/public/javascripts/govuk/selection-buttons.js

@@ -19,7 +19,7 @@
       $elms = $(elmsOrSelector);
       this.selector = elmsOrSelector;
       this.setInitialState($(this.selector));
-    } else {
+    } else if (elmsOrSelector !== undefined) {
       this.$elms = elmsOrSelector;
       this.setInitialState(this.$elms);
     }

package.json

@@ -10,7 +10,7 @@
     "consolidate": "^0.10.0",
     "express": "^3.18.4",
     "express-writer": "0.0.4",
-    "govuk_frontend_toolkit": "^4.2.1",
+    "govuk_frontend_toolkit": "^4.3.0",
     "govuk_template_mustache": "^0.15.1",
     "grunt": "^0.4.2",
     "grunt-concurrent": "^0.4.3",