fetch root posts for reshares

lib/diaspora_federation/entities/reshare.rb

@@ -27,6 +27,20 @@ module DiasporaFederation
       def to_s
         "#{super}:#{root_guid}"
       end
+
+      # fetch and receive root post from remote, if not available locally.
+      def fetch_root
+        root = DiasporaFederation.callbacks.trigger(:fetch_related_entity, "Post", root_guid)
+        Federation::Fetcher.fetch_public(root_author, "Post", root_guid) unless root
+      end
+
+      # Fetch root post after parse.
+      # @see Entity.populate_entity
+      # @param [Nokogiri::XML::Element] root_node xml nodes
+      # @return [Entity] instance
+      private_class_method def self.populate_entity(root_node)
+        new(entity_data(root_node)).tap(&:fetch_root)
+      end
     end
   end
 end

spec/lib/diaspora_federation/entities/reshare_spec.rb

@@ -1,6 +1,7 @@
 module DiasporaFederation
   describe Entities::Reshare do
-    let(:data) { FactoryGirl.attributes_for(:reshare_entity) }
+    let(:root) { FactoryGirl.create(:post, author: bob) }
+    let(:data) { FactoryGirl.attributes_for(:reshare_entity, root_guid: root.guid, root_author: bob.diaspora_id) }
 
     let(:xml) {
       <<-XML
@@ -40,5 +41,14 @@ XML
         expect(parsed_instance.provider_display_name).to be_nil
       end
     end
+
+    context "fetch root" do
+      it "fetches the root post if it is not available already" do
+        expect_callback(:fetch_related_entity, "Post", data[:root_guid]).and_return(nil)
+        expect(Federation::Fetcher).to receive(:fetch_public).with(data[:root_author], "Post", data[:root_guid])
+
+        Entities::Reshare.from_xml(Nokogiri::XML::Document.parse(xml).root)
+      end
+    end
   end
 end