1 files changed, 31 insertions, 0 deletions
diff --git a/lib/banzai/filter/color_filter.rb b/lib/banzai/filter/color_filter.rb
new file mode 100644
index 00000000000..6ab29ac281f
--- /dev/null
+++ b/lib/banzai/filter/color_filter.rb
@@ -0,0 +1,31 @@
+module Banzai
+  module Filter
+    # HTML filter that renders `color` followed by a color "chip".
+    #
+    class ColorFilter < HTML::Pipeline::Filter
+      COLOR_CHIP_CLASS = 'gfm-color_chip'.freeze
+
+      def call
+        doc.css('code').each do |node|
+          color = ColorParser.parse(node.content)
+          node << color_chip(color) if color
+        end
+
+        doc
+      end
+
+      private
+
+      def color_chip(color)
+        checkerboard = doc.document.create_element('span', class: COLOR_CHIP_CLASS)
+        chip = doc.document.create_element('span', style: inline_styles(color: color))
+
+        checkerboard << chip
+      end
+
+      def inline_styles(color:)
+        "background-color: #{color};"
+      end
+    end
+  end
+end