Render math in Asciidoc and Markdown with KaTeX using code blocks

1 files changed, 30 insertions, 1 deletions

diff --git a/lib/gitlab/asciidoc.rb b/lib/gitlab/asciidoc.rb
index 9667df4ffb8..f77f412da56 100644
--- a/lib/gitlab/asciidoc.rb
+++ b/lib/gitlab/asciidoc.rb
@@ -1,4 +1,5 @@
 require 'asciidoctor'
+require 'asciidoctor/converter/html5'
 
 module Gitlab
   # Parser/renderer for the AsciiDoc format that uses Asciidoctor and filters
@@ -23,7 +24,7 @@ module Gitlab
     def self.render(input, context, asciidoc_opts = {})
       asciidoc_opts.reverse_merge!(
         safe: :secure,
-        backend: :html5,
+        backend: :gitlab_html5,
         attributes: []
       )
       asciidoc_opts[:attributes].unshift(*DEFAULT_ADOC_ATTRS)
@@ -36,3 +37,31 @@ module Gitlab
     end
   end
 end
+
+module Gitlab
+  module Asciidoc
+    class Html5Converter < Asciidoctor::Converter::Html5Converter
+      extend Asciidoctor::Converter::Config
+
+      register_for 'gitlab_html5'
+
+      def stem(node)
+        return super unless node.style.to_sym == :latexmath
+
+        %(<pre#{id_attribute(node)} class="code math js-render-math #{node.role}" data-math-style="display"><code>#{node.content}</code></pre>)
+      end
+
+      def inline_quoted(node)
+        return super unless node.type.to_sym == :latexmath
+
+        %(<code#{id_attribute(node)} class="code math js-render-math #{node.role}" data-math-style="inline">#{node.text}</code>)
+      end
+
+      private
+
+      def id_attribute(node)
+        node.id ? %( id="#{node.id}") : nil
+      end
+    end
+  end
+end