Merge branch 'rs-fix-highlighting' into 'master'

Syntax highlighting improvements

On the server side:

During development I would occasionally see SanitizationFilter sanitizing
the result of SyntaxHighlightFilter, even though its attributes were
whitelisted. This updates the `clean_spans` transformer to return the
whitelisted node as [suggested by the Sanitize docs](http://git.io/vZR8i).

On the client side:

- Makes the syntax_highlight JS more flexible
- Adds JS specs
- Simplifies highlighting of new notes
- Adds highlighting to Markdown preview

See merge request !1278

1 files changed, 8 insertions, 4 deletions

diff --git a/lib/gitlab/markdown/sanitization_filter.rb b/lib/gitlab/markdown/sanitization_filter.rb
index 68ed57f6257..e368de7d848 100644
--- a/lib/gitlab/markdown/sanitization_filter.rb
+++ b/lib/gitlab/markdown/sanitization_filter.rb
@@ -67,12 +67,16 @@ module Gitlab
 
       def clean_spans
         lambda do |env|
-          return unless env[:node_name] == 'span'
-          return unless env[:node].has_attribute?('class')
+          node = env[:node]
 
-          unless has_ancestor?(env[:node], 'pre')
-            env[:node].remove_attribute('class')
+          return unless node.name == 'span'
+          return unless node.has_attribute?('class')
+
+          unless has_ancestor?(node, 'pre')
+            node.remove_attribute('class')
           end
+
+          { node_whitelist: [node] }
         end
       end
     end