[main] extensions options: support names containing "s"

Resolves #401

Author: pkra

lib/main.js

@@ -532,7 +532,7 @@ function ConfigureMathJax() {
     //
     // Parse added extensions list and add to standard ones
     //
-    var extensionList = extensions.split(/s*,\s*/);
+    var extensionList = extensions.split(/\s*,\s*/);
     for (var i = 0; i < extensionList.length; i++) {
       var matches = extensionList[i].match(/^(.*?)(\.js)?$/);
       window.MathJax.extensions.push(matches[1] + '.js');

test/base-config-extensions.js

@@ -0,0 +1,22 @@
+var tape = require('tape');
+var mjAPI = require('../lib/main.js');
+
+tape('Options "extension": multiple extensions', function(t) {
+  t.plan(1);
+  mjAPI.config({
+    extensions: 'TeX/autoload-all.js, TeX/color.js'
+  });
+  mjAPI.typeset(
+    {
+      math: 'E = mc^2',
+      format: 'TeX',
+      mml: true
+    },
+    function(data) {
+      t.notOk(
+        data.errors,
+        'Config block with multiple extensions throws no error'
+      );
+    }
+  );
+});