added favorite unit tests

test/unit/favorite_test.rb

@@ -1,8 +1,40 @@
-require 'test_helper'
+require File.dirname(__FILE__) + '/../test_helper'
 
 class FavoriteTest < ActiveSupport::TestCase
-  # Replace this with your real tests.
-  test "the truth" do
-    assert true
+  context "A favorite" do
+    should "know which table it belongs to" do
+      user1 = Factory.create(:user)
+      user2 = Factory.create(:user)      
+      p1 = Factory.create(:post)
+      p2 = Factory.create(:post)
+    
+      p1.add_favorite(user1)
+      p2.add_favorite(user1)
+      p1.add_favorite(user2)
+    
+      favorites = user1.favorite_posts
+      assert_equal(2, favorites.size)
+      assert_equal(p2.id, favorites[0].id)
+      assert_equal(p1.id, favorites[1].id)
+      
+      favorites = user2.favorite_posts
+      assert_equal(1, favorites.size)
+      assert_equal(p1.id, favorites[0].id)
+    end
+    
+    should "filter before a given id" do
+      user1 = Factory.create(:user)
+      p1 = Factory.create(:post)
+      p2 = Factory.create(:post)
+      p3 = Factory.create(:post)
+      p1.add_favorite(user1)
+      p2.add_favorite(user1)
+      p3.add_favorite(user1)
+      favorites = user1.favorite_posts(:limit => 1)
+      favorites = user1.favorite_posts(:before => favorites.first.favorite_id)
+      assert_equal(2, favorites.size)
+      assert_equal(p2.id, favorites[0].id)
+      assert_equal(p1.id, favorites[1].id)
+    end
   end
 end