fixup! Move default highlight.js highlighting into a web worker

Author: Steve Day

public/js/highlight.js renamed to public/js/highlight-worker.js

@@ -2,6 +2,6 @@
 // See: https://highlightjs.org/usage/
 onmessage = function(event) {
     importScripts('/vendor/plugins/highlight/highlight.pack.js');
-    var result = self.hljs.highlightAuto(event.data);
-    postMessage(result.value);
+    var result = self.hljs.highlightAuto(event.data.text);
+    postMessage({index: event.data.index, html: result.value});
 };

public/js/index.js

@@ -1430,12 +1430,13 @@ $(document).ready(function () {
 
     // Highlight JS
     if (typeof hljs != 'undefined') {
-        $('pre code').each(function (index, element) {
-            var worker = new Worker('/js/highlight-worker.js');
-            worker.onmessage = function(event) {
-                $(element).html(event.data);
-            }
-            worker.postMessage($(element).text());
+        var codeElements = $('pre code');
+        var worker = new Worker('/js/highlight-worker.js');
+        worker.onmessage = function(event) {
+            $(codeElements[event.data.index]).html(event.data.html);
+        }
+        $(codeElements).each(function (index, element) {
+            worker.postMessage({index: index, text: $(element).text()});
         });
     }