add tag subscriptions

test/factories/tag_subscription.rb

@@ -0,0 +1,5 @@
+Factory.define(:tag_subscription) do |f|
+  f.owner {|x| x.association(:user)}
+  f.name {Faker::Lorem.words.join(" ")}
+  f.is_visible_on_profile true
+end

test/fixtures/tag_subscriptions.yml

@@ -0,0 +1,11 @@
+# Read about fixtures at http://ar.rubyonrails.org/classes/Fixtures.html
+
+# This model initially had no columns defined.  If you add columns to the
+# model remove the '{}' from the fixture names and add the columns immediately
+# below each fixture, per the syntax in the comments below
+#
+one: {}
+# column: value
+#
+two: {}
+#  column: value

test/unit/related_tag_calculator_test.rb

@@ -13,7 +13,7 @@ class RelatedTagCalculatorTest < ActiveSupport::TestCase
       assert_equal({"bbb" => 3, "ccc" => 2, "ddd" => 1}, calculator.calculate_from_sample("aaa", 10))
     end
 
-    should "calculate related tags for a tag" do
+    should "calculate typed related tags for a tag" do
       posts = []
       posts << Factory.create(:post, :tag_string => "aaa bbb art:ccc copy:ddd")
       posts << Factory.create(:post, :tag_string => "aaa bbb art:ccc")

test/unit/tag_subscription_test.rb

@@ -0,0 +1,65 @@
+require File.dirname(__FILE__) + '/../test_helper'
+
+class TagSubscriptionTest < ActiveSupport::TestCase
+  context "A tag subscription" do
+    should "find the union of all posts for each tag in its tag query" do
+      posts = []
+      user = Factory.create(:user)
+      posts << Factory.create(:post, :tag_string => "aaa")
+      posts << Factory.create(:post, :tag_string => "bbb")
+      posts << Factory.create(:post, :tag_string => "ccc")
+      posts << Factory.create(:post, :tag_string => "ddd")
+      sub_1 = Factory.create(:tag_subscription, :tag_query => "aaa bbb", :owner => user, :name => "zzz")
+      sub_2 = Factory.create(:tag_subscription, :tag_query => "ccc", :owner => user, :name => "yyy")
+      assert_equal([posts[1].id, posts[0].id], TagSubscription.find_posts(user.id, "zzz").map(&:id))
+      assert_equal([posts[2].id, posts[1].id, posts[0].id], TagSubscription.find_posts(user.id).map(&:id))
+    end
+    
+    should "cache its tag query results" do
+      posts = []
+      user = Factory.create(:user)
+      posts << Factory.create(:post, :tag_string => "aaa")
+      posts << Factory.create(:post, :tag_string => "bbb")
+      posts << Factory.create(:post, :tag_string => "ccc")
+      sub = Factory.create(:tag_subscription, :tag_query => "aaa bbb", :owner => user, :name => "zzz")
+      assert_equal("#{posts[1].id},#{posts[0].id}", sub.post_ids)
+    end
+    
+    should "find posts based on its cached post ids" do
+      user = Factory.create(:user)
+      subs = []
+      subs << Factory.create(:tag_subscription, :tag_query => "aaa", :owner => user, :name => "zzz")
+      subs << Factory.create(:tag_subscription, :tag_query => "bbb", :owner => user, :name => "yyy")
+      assert_equal([], TagSubscription.find_posts(user.id))
+      assert_equal([], TagSubscription.find_posts(user.id, "zzz"))
+      assert_equal([], TagSubscription.find_posts(user.id, "yyy"))
+      posts = []
+      posts << Factory.create(:post, :tag_string => "aaa")
+      posts << Factory.create(:post, :tag_string => "bbb")
+      posts << Factory.create(:post, :tag_string => "ccc")
+      subs.each {|x| x.process; x.save}
+      assert_equal([posts[1].id, posts[0].id], TagSubscription.find_posts(user.id).map(&:id))
+      assert_equal([posts[0].id], TagSubscription.find_posts(user.id, "zzz").map(&:id))
+      assert_equal([posts[1].id], TagSubscription.find_posts(user.id, "yyy").map(&:id))
+    end
+  end
+
+  context "A tag subscription manager" do
+    should "process all active tag subscriptions" do
+      users = []
+      users << Factory.create(:user)
+      users << Factory.create(:user)
+      posts = []
+      posts << Factory.create(:post, :tag_string => "aaa")
+      posts << Factory.create(:post, :tag_string => "bbb")
+      posts << Factory.create(:post, :tag_string => "ccc")
+      subscriptions = []
+      subscriptions << Factory.create(:tag_subscription, :tag_query => "aaa", :owner => users[0])
+      subscriptions << Factory.create(:tag_subscription, :tag_query => "bbb", :owner => users[1])
+      TagSubscription.process_all
+      subscriptions.each {|x| x.reload}
+      assert_equal("#{posts[0].id}", subscriptions[0].post_ids)
+      assert_equal("#{posts[1].id}", subscriptions[1].post_ids)
+    end
+  end
+end