add backwards compatible Gollum::Wiki.markup_class

lib/gollum/wiki.rb

@@ -66,6 +66,16 @@ module Gollum
           end
       end
 
+      def markup_class
+        markup_classes[:default]
+      end
+
+      def markup_class=(default)
+        new_classes     = Hash.new default
+        @markup_classes = Hash.new(default).update(markup_classes)
+        default
+      end
+
       # Gets the default sanitization options for current pages used by
       # instances of this Wiki.
       def sanitization

test/test_wiki.rb

@@ -4,6 +4,20 @@ require File.expand_path(File.join(File.dirname(__FILE__), "helper"))
 context "Wiki" do
   setup do
     @wiki = Gollum::Wiki.new(testpath("examples/lotr.git"))
+    Gollum::Wiki.markup_classes = nil
+  end
+
+  test "#markup_class gets default markup" do
+    assert_equal Gollum::Markup, Gollum::Wiki.markup_class
+  end
+
+  test "#markup_class= doesn't clobber alternate markups" do
+    custom = Class.new(Gollum::Markup)
+    Gollum::Wiki.markup_class = custom
+
+    assert_equal custom, Gollum::Wiki.markup_class
+    assert_equal custom, Gollum::Wiki.markup_classes[:orgmode]
+    assert_equal Gollum::MarkupGFM, Gollum::Wiki.markup_classes[:markdown]
   end
 
   test "repo path" do