1 files changed, 40 insertions, 0 deletions
diff --git a/lib/gitlab/markdown/redactor_filter.rb b/lib/gitlab/markdown/redactor_filter.rb
new file mode 100644
index 00000000000..a1f3a8a8ebf
--- /dev/null
+++ b/lib/gitlab/markdown/redactor_filter.rb
@@ -0,0 +1,40 @@
+require 'gitlab/markdown'
+require 'html/pipeline/filter'
+
+module Gitlab
+  module Markdown
+    # HTML filter that removes references to records that the current user does
+    # not have permission to view.
+    #
+    # Expected to be run in its own post-processing pipeline.
+    #
+    class RedactorFilter < HTML::Pipeline::Filter
+      def call
+        doc.css('a.gfm').each do |node|
+          unless user_can_reference?(node)
+            node.replace(node.text)
+          end
+        end
+
+        doc
+      end
+
+      private
+
+      def user_can_reference?(node)
+        if node.has_attribute?('data-reference-filter')
+          reference_type = node.attr('data-reference-filter')
+          reference_filter = reference_type.constantize
+
+          reference_filter.user_can_reference?(current_user, node, context)
+        else
+          true
+        end
+      end
+
+      def current_user
+        context[:current_user]
+      end
+    end
+  end
+end