Support for a new site setting: newuser_spam_host_threshold. If a new user posts a link

to the same host enough tiles, they will not be able to post the same link again.

Additionally, the site will flag all their previous posts with links as spam and they will
be instantly hidden via the auto hide workflow.

spec/controllers/posts_controller_spec.rb

@@ -273,6 +273,31 @@ describe PostsController do
         ::JSON.parse(response.body).should be_present
       end
 
+      context "errors" do
+
+        let(:post_with_errors) { Fabricate.build(:post, user: user)}
+
+        before do
+          post_with_errors.errors.add(:base, I18n.t(:spamming_host))
+          PostCreator.any_instance.stubs(:errors).returns(post_with_errors.errors)
+          PostCreator.any_instance.expects(:create).returns(post_with_errors)
+        end
+
+        it "does not succeed" do
+          xhr :post, :create, post: {raw: 'test'}
+          User.any_instance.expects(:flag_linked_posts_as_spam).never
+          response.should_not be_success
+        end
+
+        it "it triggers flag_linked_posts_as_spam when the post creator returns spam" do
+          PostCreator.any_instance.expects(:spam?).returns(true)
+          User.any_instance.expects(:flag_linked_posts_as_spam)
+          xhr :post, :create, post: {raw: 'test'}
+        end
+
+      end
+
+
       context "parameters" do
 
         let(:post_creator) { mock }