add subscription model

app/models/rubygem.rb

@@ -3,6 +3,8 @@ class Rubygem < ActiveRecord::Base
 
   has_many :owners, :through => :ownerships, :source => :user
   has_many :ownerships
+  has_many :subscribers, :through => :subscriptions, :source => :user
+  has_many :subscriptions
   has_many :versions, :dependent => :destroy, :order => "created_at desc, number desc" do
     def latest
       self.find(:first, :order => "updated_at desc")

app/models/subscription.rb

@@ -0,0 +1,6 @@
+class Subscription < ActiveRecord::Base
+  belongs_to :rubygem
+  belongs_to :user
+
+  validates_uniqueness_of :rubygem_id, :scope => :user_id
+end

app/models/user.rb

@@ -4,7 +4,11 @@ class User < ActiveRecord::Base
   has_many :rubygems, :through    => :ownerships,
                       :order      => "name ASC",
                       :conditions => { 'ownerships.approved' => true }
+  has_many :subscribed_gems, :through => :subscriptions,
+                             :source  => :rubygem,
+                             :order   => "name ASC"
   has_many :ownerships
+  has_many :subscriptions
   before_create :generate_api_key
 
   protected

db/migrate/20090825173917_create_subscriptions.rb

@@ -0,0 +1,13 @@
+class CreateSubscriptions < ActiveRecord::Migration
+  def self.up
+    create_table :subscriptions do |t|
+      t.references :rubygem
+      t.references :user
+      t.timestamps
+    end
+  end
+
+  def self.down
+    drop_table :subscriptions
+  end
+end

db/schema.rb

@@ -9,7 +9,7 @@
 #
 # It's strongly recommended to check this file into your version control system.
 
-ActiveRecord::Schema.define(:version => 20090821044418) do
+ActiveRecord::Schema.define(:version => 20090825173917) do
 
   create_table "delayed_jobs", :force => true do |t|
     t.integer  "priority",   :default => 0
@@ -72,6 +72,13 @@
 
   add_index "rubygems", ["name"], :name => "index_rubygems_on_name"
 
+  create_table "subscriptions", :force => true do |t|
+    t.integer  "rubygem_id"
+    t.integer  "user_id"
+    t.datetime "created_at"
+    t.datetime "updated_at"
+  end
+
   create_table "users", :force => true do |t|
     t.string   "email"
     t.string   "encrypted_password", :limit => 128

test/factories/subscription.rb

@@ -0,0 +1,4 @@
+Factory.define :subscription do |subscription|
+  subscription.association(:rubygem)
+  subscription.association(:user)
+end

test/unit/rubygem_test.rb

@@ -123,6 +123,19 @@ class RubygemTest < ActiveSupport::TestCase
       end
     end
 
+    context "with subscribed users" do
+      setup do
+        @subscribed_user   = Factory(:user)
+        @unsubscribed_user = Factory(:user)
+        Factory(:subscription, :rubygem => @rubygem, :user => @subscribed_user)
+      end
+
+      should "only fetch the subscribed users with #subscribers" do
+        assert_contains         @rubygem.subscribers, @subscribed_user
+        assert_does_not_contain @rubygem.subscribers, @unsubscribed_user
+      end
+    end
+
     should "return current version" do
       assert_equal @rubygem.versions.first, @rubygem.versions.current
     end

test/unit/subscription_test.rb

@@ -0,0 +1,20 @@
+require File.dirname(__FILE__) + '/../test_helper'
+
+class SubscriptionTest < ActiveSupport::TestCase
+  should_belong_to :rubygem
+  should_belong_to :user
+
+  context "with a linkset" do
+    setup do
+      @subscription = Factory.create(:subscription)
+    end
+
+    subject { @subscription }
+
+    should_validate_uniqueness_of :rubygem_id, :scoped_to => :user_id
+
+    should "be valid with factory" do
+      assert_valid @subscription
+    end
+  end
+end

test/unit/user_test.rb

@@ -3,6 +3,8 @@
 class UserTest < ActiveSupport::TestCase
   should_have_many :rubygems, :through => :ownerships
   should_have_many :ownerships
+  should_have_many :subscribed_gems, :through => :subscriptions
+  should_have_many :subscriptions
 
   context "with a user" do
     setup do
@@ -21,5 +23,18 @@ class UserTest < ActiveSupport::TestCase
 
       assert_equal [my_rubygem], @user.rubygems
     end
+
+    context "with subscribed gems" do
+      setup do
+        @subscribed_gem   = Factory(:rubygem)
+        @unsubscribed_gem = Factory(:rubygem)
+        Factory(:subscription, :user => @user, :rubygem => @subscribed_gem)
+      end
+
+      should "only fetch the subscribed gems with #subscribed_gems" do
+        assert_contains         @user.subscribed_gems, @subscribed_gem
+        assert_does_not_contain @user.subscribed_gems, @unsubscribed_gem
+      end
+    end
   end
 end