Initial support for mocking delete_message.

I need to investigate the actual exceptions in those two cases.

lib/fog/rackspace/queues.rb

@@ -143,6 +143,13 @@ module Fog
             Time.now.to_i - @created
           end
 
+          # Return true if this message has been claimed.
+          #
+          # @return [Boolean]
+          def claimed?
+            ! @claimant_id.nil?
+          end
+
           # Convert this message to a GET payload.
           #
           # @return [Hash]

lib/fog/rackspace/requests/queues/create_message.rb

@@ -38,6 +38,8 @@ module Fog
           queue = data[queue_name]
           raise NotFound.new unless queue
 
+          raise BadRequest.new if body.nil? || body.empty?
+
           message = queue.add_message(client_id, body, ttl)
 
           # FIXME: refactor /v1/queues out to an inherited constant

lib/fog/rackspace/requests/queues/delete_message.rb

@@ -1,6 +1,7 @@
 module Fog
   module Rackspace
     class Queues
+
       class Real
 
         # This operation immediately deletes the specified message.
@@ -26,7 +27,34 @@ module Fog
             :query => query
           )
         end
+
       end
+
+      class Mock
+        def delete_message(queue_name, message_id, options = {})
+          queue = data[queue_name]
+          raise NotFound.new unless queue
+
+          claim_id = options[:claim_id]
+
+          message = queue.messages.detect { |m| m.id == message_id }
+
+          if message.claimed?
+            unless message.claimant_id == claim_id
+              # Exception
+            end
+          else
+            unless claim_id
+              # Exception
+            end
+          end
+
+          response = Excon::Response.new
+          response.status = 204
+          response
+        end
+      end
+
     end
   end
 end

lib/fog/rackspace/requests/queues/list_messages.rb

@@ -53,7 +53,7 @@ module Fog
           next_marker = marker + limit + 1
           messages = queue.messages[marker...next_marker]
           messages.reject! { |m| m.producer_id == client_id } unless echo
-          messages.select! { |m| m.claimant_id.nil? } unless include_claimed
+          messages.reject! { |m| m.claimed? } unless include_claimed
 
           response = Excon::Response.new
           if queue.messages.empty?