Use new ShortId class to generate short id

app/models/message.rb

@@ -15,24 +15,14 @@ class Message < ActiveRecord::Base
 
   validates_length_of :subject, :in => 1..150
   validates_length_of :body, :maximum => (64 * 1024)
-  
+
   before_create :assign_short_id
   after_create :deliver_reply_notifications
   after_save :check_for_both_deleted
   after_save :update_unread_counts
- 
+
   def assign_short_id
-    10.times do |try|
-      if try == 10
-        raise "too many hash collisions"
-      end
-
-      self.short_id = Utils.random_str(6)
-
-      if !Message.find_by_short_id(self.short_id)
-        break
-      end
-    end
+    self.short_id = ShortId.new(self.class).generate
   end
 
   def check_for_both_deleted
@@ -44,7 +34,7 @@ class Message < ActiveRecord::Base
   def update_unread_counts
     self.recipient.update_unread_message_count!
   end
-  
+
   def deliver_reply_notifications
     begin
       if self.recipient.email_messages?
@@ -81,12 +71,12 @@ class Message < ActiveRecord::Base
   def body=(b)
     self[:body] = b.to_s.remove_mb4
   end
-  
+
   # TODO: remove remove_mb4 hack
   def subject=(s)
     self[:subject] = s.to_s.remove_mb4
   end
-  
+
   def linkified_body
     Markdowner.to_html(self.body)
   end

spec/models/message_spec.rb

@@ -0,0 +1,8 @@
+require "spec_helper"
+
+describe Message do
+  it "should get a short id" do
+    m = Message.make!
+    m.short_id.should match(/^\A[a-zA-Z0-9]{1,10}\z/)
+  end
+end

spec/support/blueprints.rb

@@ -28,3 +28,10 @@ Comment.blueprint do
   story_id { Story.make!.id }
   comment { "comment text #{sn}" }
 end
+
+Message.blueprint do
+  recipient_user_id { User.make!.id }
+  author_user_id { User.make!.id }
+  subject { "message subject #{sn}" }
+  body { "message body #{sn}" }
+end