added default thumbo_uri and corresponded test. TODO: fix test

lib/thumbo.rb

@@ -53,11 +53,15 @@ def thumbos
      @thumbos ||= init_thumbos
   end
 
-  # same as thumbnail.filename, for writing
   def thumbo_filename thumbo
     "#{object_id}_#{thumbo.title}.#{thumbo.fileext}"
   end
 
+  def thumbo_uri thumbo
+    paths = thumbo.paths
+    paths[rand(paths.size)]
+  end
+
   def thumbo_mime_type
     thumbos[:original].mime_type
   end

test/test_storage.rb

@@ -1,5 +1,6 @@
 
 require 'test/helper'
+require 'digest/md5'
 
 class Photo
   include Thumbo
@@ -30,6 +31,22 @@ def thumbo_default_fileext
 
 end
 
+class ThumboDefault
+  include Thumbo
+
+  def self.thumbo_common
+    {:common => 200}
+  end
+
+  def self.thumbo_square
+    {:square => 50}
+  end
+
+  def thumbo_default_fileext
+    'png'
+  end
+end
+
 class StorageTest < MiniTest::Unit::TestCase
   def test_uri
     p = Photo.new
@@ -40,6 +57,19 @@ def test_uri
                   p.thumbos[:original].uri )
   end
 
+  def test_default
+    p = ThumboDefault.new
+    t = p.thumbos[:original]
+    t.from_blob(File.open('test/ruby.png').read)
+    t.write
+
+    assert_equal( "public/images/thumbo/#{Digest::MD5.hexdigest(t.filename)[0,1]}" +
+                  "/#{p.object_id}_original.png",
+                  p.thumbos[:original].uri )
+  ensure
+    File.delete(t.uri)
+  end
+
   def test_raises
     assert_raises(Thumbo::FileNotFound) do
       Photo.new.thumbos[:original].delete