Remove topic links when a post is deleted

app/models/post.rb

@@ -25,6 +25,7 @@ class Post < ActiveRecord::Base
   has_many :post_replies
   has_many :replies, through: :post_replies
   has_many :post_actions
+  has_many :topic_links
 
   has_and_belongs_to_many :upload
 
@@ -52,9 +53,15 @@ class Post < ActiveRecord::Base
     @types ||= Enum.new(:regular, :moderator_action)
   end
 
+  def trash!
+    self.topic_links.each(&:destroy)
+    super
+  end
+
   def recover!
     super
     update_flagged_posts_count
+    TopicLink.extract_from(self)
   end
 
   # The key we use in redis to ensure unique posts

app/models/topic_link.rb

@@ -13,7 +13,7 @@ class TopicLink < ActiveRecord::Base
 
   validates_uniqueness_of :url, scope: [:topic_id, :post_id]
 
-  has_many :topic_link_clicks
+  has_many :topic_link_clicks, dependent: :destroy
 
   validate :link_to_self
 

lib/post_destroyer.rb

@@ -69,6 +69,7 @@ class PostDestroyer
       @post.revise(@user, I18n.t('js.post.deleted_by_author'), force_new_version: true)
       @post.update_column(:user_deleted, true)
       @post.update_flagged_posts_count
+      @post.topic_links.each(&:destroy)
     end
   end
 

spec/components/post_destroyer_spec.rb

@@ -166,5 +166,23 @@ describe PostDestroyer do
     end
   end
 
+  describe 'topic links' do
+    let!(:first_post)  { Fabricate(:post) }
+    let!(:topic)       { first_post.topic }
+    let!(:second_post) { Fabricate(:post_with_external_links, topic: topic) }
+
+    before { TopicLink.extract_from(second_post) }
+
+    it 'should destroy the topic links when moderator destroys the post' do
+      PostDestroyer.new(moderator, second_post.reload).destroy
+      expect(topic.topic_links.count).to eq(0)
+    end
+
+    it 'should destroy the topic links when the user destroys the post' do
+      PostDestroyer.new(second_post.user, second_post.reload).destroy
+      expect(topic.topic_links.count).to eq(0)
+    end
+  end
+
 end
 

spec/models/post_spec.rb

@@ -56,26 +56,44 @@ describe Post do
   end
 
   describe "versions and deleting/recovery" do
-    let(:post) { Fabricate(:post, post_args) }
 
-    before do
-      post.trash!
-      post.reload
-    end
+    context 'a post without links' do
+      let(:post) { Fabricate(:post, post_args) }
 
-    it "doesn't create a new version when deleted" do
-      post.versions.count.should == 0
-    end
-
-    describe "recovery" do
       before do
-        post.recover!
+        post.trash!
         post.reload
       end
 
-      it "doesn't create a new version when recovered" do
+      it "doesn't create a new version when deleted" do
         post.versions.count.should == 0
       end
+
+      describe "recovery" do
+        before do
+          post.recover!
+          post.reload
+        end
+
+        it "doesn't create a new version when recovered" do
+          post.versions.count.should == 0
+        end
+      end
+    end
+
+    context 'a post with links' do
+      let(:post) { Fabricate(:post_with_external_links) }
+      before do
+        post.trash!
+        post.reload
+      end
+
+      describe 'recovery' do
+        it 'recreates the topic_link records' do
+          TopicLink.expects(:extract_from).with(post)
+          post.recover!
+        end
+      end
     end
 
   end