adds specs

spec/models/comment_spec.rb

@@ -36,4 +36,34 @@ describe Comment do
       expect(comment).to be_as_moderator
     end
   end
+
+  describe "cache" do
+    let(:comment) { create(:comment) }
+
+    it "should expire cache when it has a new vote" do
+      expect { create(:vote, votable: comment) }
+      .to change { comment.updated_at }
+    end
+
+    it "should expire cache when hidden" do
+      expect { comment.hide }
+      .to change { comment.updated_at }
+    end
+
+    it "should expire cache when the author is hidden" do
+      expect { comment.user.hide }
+      .to change { comment.reload.updated_at }
+    end
+
+    it "should expire cache when the author changes" do
+      expect { comment.user.update(username: "Isabel") }
+      .to change { comment.reload.updated_at }
+    end
+
+    it "should expire cache when the author's organization get verified" do
+      create(:organization, user: comment.user)
+      expect { comment.user.organization.verify }
+      .to change { comment.reload.updated_at}
+    end
+  end
 end