Added the ability to configure the file extensions to be processed by each converter. Test cases included.

lib/jekyll.rb

@@ -64,6 +64,9 @@ module Jekyll
     'pygments'     => false,
     'markdown'     => 'maruku',
     'permalink'    => 'date',
+    
+    'markdown_ext' => 'markdown,mdw,mdwn,md',
+    'textile_ext'  => 'textile',
 
     'maruku'       => {
       'use_tex'    => false,

lib/jekyll/converters/markdown.rb

@@ -65,9 +65,10 @@ module Jekyll
       end
       @setup = true
     end
-
+    
     def matches(ext)
-      ext =~ /(markdown|mkdn?|md)/i
+      rgx = '(' + @config['markdown_ext'].gsub(',','|') +')'
+      ext =~ Regexp.new(rgx, Regexp::IGNORECASE)
     end
 
     def output_ext(ext)

lib/jekyll/converters/textile.rb

@@ -17,7 +17,8 @@ module Jekyll
     end
 
     def matches(ext)
-      ext =~ /textile/i
+      rgx = '(' + @config['textile_ext'].gsub(',','|') +')'
+      ext =~ Regexp.new(rgx, Regexp::IGNORECASE)
     end
 
     def output_ext(ext)

test/source/_posts/2011-04-12-md-extension.md

@@ -0,0 +1,7 @@
+---
+date: 2011-04-12 13:07:09
+---
+
+under default configuration, this post should get processed by the identity converter. By changing 
+textile extension or markdown extension configuration parameters, you should be able to associate
+it with either of those converters

test/test_generated_site.rb

@@ -14,7 +14,7 @@ class TestGeneratedSite < Test::Unit::TestCase
     end
 
     should "ensure post count is as expected" do
-      assert_equal 26, @site.posts.size
+      assert_equal 28, @site.posts.size
     end
 
     should "insert site.posts into the index" do

test/test_post.rb

@@ -391,6 +391,47 @@ class TestPost < Test::Unit::TestCase
       post = Post.new(@site, File.join(File.dirname(__FILE__), *%w[source]), 'foo', 'bar/2008-12-12-topical-post.textile')
       assert_equal ['foo'], post.categories
     end
-
   end
+  
+  context "converter file extension settings" do
+    setup do
+      stub(Jekyll).configuration { Jekyll::DEFAULTS }
+      @site = Site.new(Jekyll.configuration)
+    end
+    
+    should "process .md as markdown under default configuration" do
+      post = setup_post '2011-04-12-md-extension.md'
+      conv = post.converter
+      assert conv.kind_of? Jekyll::MarkdownConverter
+    end
+    
+    should "process .text as indentity under default configuration" do
+      post = setup_post '2011-04-12-text-extension.text'
+      conv = post.converter
+      assert conv.kind_of? Jekyll::IdentityConverter
+    end
+    
+    should "process .text as markdown under alternate configuration" do
+      @site.config['markdown_ext'] = 'markdown,mdw,mdwn,md,text'
+      post = setup_post '2011-04-12-text-extension.text'
+      conv = post.converter
+      assert conv.kind_of? Jekyll::MarkdownConverter
+    end
+    
+    should "process .md as markdown under alternate configuration" do
+      @site.config['markdown_ext'] = 'markdown,mdw,mdwn,md,text'
+      post = setup_post '2011-04-12-text-extension.text'
+      conv = post.converter
+      assert conv.kind_of? Jekyll::MarkdownConverter
+    end
+    
+    should "process .text as textile under alternate configuration" do
+      @site.config['textile_ext'] = 'textile,text'
+      post = setup_post '2011-04-12-text-extension.text'
+      conv = post.converter
+      assert conv.kind_of? Jekyll::TextileConverter
+    end
+    
+  end
+  
 end