Possible fix with failing test

Maybe the test is wrong

notebook/jstest.py

@@ -230,6 +230,8 @@ class JSController(TestController):
         includes = '--includes=' + os.path.join(js_test_dir,'util.js')
         test_cases = os.path.join(js_test_dir, self.section)
         self.cmd = ['casperjs', 'test', includes, test_cases, '--engine=%s' % self.engine]
+        # self.cmd = ['casperjs', 'test', includes, test_cases, '--engine=%s' % self.engine,
+        #             '--remote-debugger-port=9000']
 
     def setup(self):
         self.ipydir = TemporaryDirectory()

notebook/static/notebook/js/notebook.js

@@ -113,7 +113,7 @@ define(function (require) {
                         }
                     }, function (err) {
                         console.log("No CodeMirror mode: " + lang);
-                        callback(err, code);
+                        callback(null, code);
                     });
                 }
             });

notebook/tests/notebook/markdown.js

@@ -76,7 +76,7 @@ casper.notebook_test(function () {
     this.test.assertEquals(output.trim(), result, 'Markdown code block no language');
 
     codeblock = '```aaaa\nx = 1\n```'
-    result = '<pre><code>x = 1\n</code></pre>'
+    result = '<pre><code class="cm-s-ipython language-aaaa">x = 1\n</code></pre>'
     output = this.evaluate(md_render, {text: codeblock});
     this.test.assertEquals(output.trim(), result, 'Markdown code block unknown language');
 });