Fix RSS feeds not being cachable (#14368)

* Add tests for some cachable responses

This only covers responses that we should have managed to make cachable
so far. It's not the case of all responses that should be cachable in
the end.

* Fix RSS feeds not being cachable

app/controllers/application_controller.rb

@@ -55,7 +55,7 @@ class ApplicationController < ActionController::Base
   end
 
   def store_current_location
-    store_location_for(:user, request.url) unless request.format == :json
+    store_location_for(:user, request.url) unless [:json, :rss].include?(request.format&.to_sym)
   end
 
   def require_admin!

spec/controllers/accounts_controller_spec.rb

@@ -5,6 +5,21 @@ RSpec.describe AccountsController, type: :controller do
 
   let(:account) { Fabricate(:user).account }
 
+  shared_examples 'cachable response' do
+    it 'does not set cookies' do
+      expect(response.cookies).to be_empty
+      expect(response.headers['Set-Cookies']).to be nil
+    end
+
+    it 'does not set sessions' do
+      expect(session).to be_empty
+    end
+
+    it 'returns public Cache-Control header' do
+      expect(response.headers['Cache-Control']).to include 'public'
+    end
+  end
+
   describe 'GET #show' do
     let(:format) { 'html' }
 
@@ -323,9 +338,7 @@ RSpec.describe AccountsController, type: :controller do
           expect(response.content_type).to eq 'application/activity+json'
         end
 
-        it 'returns public Cache-Control header' do
+        it_behaves_like 'cachable response'
-          expect(response.headers['Cache-Control']).to include 'public'
-        end
 
         it 'renders account' do
           json = body_as_json
@@ -343,9 +356,7 @@ RSpec.describe AccountsController, type: :controller do
             expect(response.content_type).to eq 'application/activity+json'
           end
 
-          it 'returns public Cache-Control header' do
+          it_behaves_like 'cachable response'
-            expect(response.headers['Cache-Control']).to include 'public'
-          end
 
           it 'returns Vary header with Signature' do
             expect(response.headers['Vary']).to include 'Signature'
@@ -401,9 +412,7 @@ RSpec.describe AccountsController, type: :controller do
           expect(response.content_type).to eq 'application/activity+json'
         end
 
-        it 'returns public Cache-Control header' do
+        it_behaves_like 'cachable response'
-          expect(response.headers['Cache-Control']).to include 'public'
-        end
 
         it 'renders account' do
           json = body_as_json
@@ -447,9 +456,7 @@ RSpec.describe AccountsController, type: :controller do
           expect(response).to have_http_status(200)
         end
 
-        it 'returns public Cache-Control header' do
+        it_behaves_like 'cachable response'
-          expect(response.headers['Cache-Control']).to include 'public'
-        end
       end
 
       context do

spec/controllers/activitypub/collections_controller_spec.rb

@@ -6,6 +6,21 @@ RSpec.describe ActivityPub::CollectionsController, type: :controller do
   let!(:account) { Fabricate(:account) }
   let(:remote_account) { nil }
 
+  shared_examples 'cachable response' do
+    it 'does not set cookies' do
+      expect(response.cookies).to be_empty
+      expect(response.headers['Set-Cookies']).to be nil
+    end
+
+    it 'does not set sessions' do
+      expect(session).to be_empty
+    end
+
+    it 'returns public Cache-Control header' do
+      expect(response.headers['Cache-Control']).to include 'public'
+    end
+  end
+
   before do
     allow(controller).to receive(:signed_request_account).and_return(remote_account)
 
@@ -31,9 +46,7 @@ RSpec.describe ActivityPub::CollectionsController, type: :controller do
           expect(response.content_type).to eq 'application/activity+json'
         end
 
-        it 'returns public Cache-Control header' do
+        it_behaves_like 'cachable response'
-          expect(response.headers['Cache-Control']).to include 'public'
-        end
 
         it 'returns orderedItems with pinned statuses' do
           json = body_as_json
@@ -58,9 +71,7 @@ RSpec.describe ActivityPub::CollectionsController, type: :controller do
             expect(response.content_type).to eq 'application/activity+json'
           end
 
-          it 'returns public Cache-Control header' do
+          it_behaves_like 'cachable response'
-            expect(response.headers['Cache-Control']).to include 'public'
-          end
 
           it 'returns orderedItems with pinned statuses' do
             json = body_as_json

spec/controllers/activitypub/outboxes_controller_spec.rb

@@ -3,6 +3,21 @@ require 'rails_helper'
 RSpec.describe ActivityPub::OutboxesController, type: :controller do
   let!(:account) { Fabricate(:account) }
 
+  shared_examples 'cachable response' do
+    it 'does not set cookies' do
+      expect(response.cookies).to be_empty
+      expect(response.headers['Set-Cookies']).to be nil
+    end
+
+    it 'does not set sessions' do
+      expect(session).to be_empty
+    end
+
+    it 'returns public Cache-Control header' do
+      expect(response.headers['Cache-Control']).to include 'public'
+    end
+  end
+
   before do
     Fabricate(:status, account: account, visibility: :public)
     Fabricate(:status, account: account, visibility: :unlisted)
@@ -39,9 +54,7 @@ RSpec.describe ActivityPub::OutboxesController, type: :controller do
           expect(json[:totalItems]).to eq 4
         end
 
-        it 'returns public Cache-Control header' do
+        it_behaves_like 'cachable response'
-          expect(response.headers['Cache-Control']).to include 'public'
-        end
       end
 
       context 'with page requested' do
@@ -62,9 +75,7 @@ RSpec.describe ActivityPub::OutboxesController, type: :controller do
           expect(json[:orderedItems].all? { |item| item[:to].include?(ActivityPub::TagManager::COLLECTIONS[:public]) || item[:cc].include?(ActivityPub::TagManager::COLLECTIONS[:public]) }).to be true
         end
 
-        it 'returns public Cache-Control header' do
+        it_behaves_like 'cachable response'
-          expect(response.headers['Cache-Control']).to include 'public'
-        end
       end
     end
 

spec/controllers/activitypub/replies_controller_spec.rb

@@ -7,6 +7,21 @@ RSpec.describe ActivityPub::RepliesController, type: :controller do
   let(:remote_reply_id) { nil }
   let(:remote_account) { nil }
 
+  shared_examples 'cachable response' do
+    it 'does not set cookies' do
+      expect(response.cookies).to be_empty
+      expect(response.headers['Set-Cookies']).to be nil
+    end
+
+    it 'does not set sessions' do
+      expect(session).to be_empty
+    end
+
+    it 'returns public Cache-Control header' do
+      expect(response.headers['Cache-Control']).to include 'public'
+    end
+  end
+
   before do
     allow(controller).to receive(:signed_request_account).and_return(remote_account)
 
@@ -36,9 +51,7 @@ RSpec.describe ActivityPub::RepliesController, type: :controller do
           expect(response.content_type).to eq 'application/activity+json'
         end
 
-        it 'returns public Cache-Control header' do
+        it_behaves_like 'cachable response'
-          expect(response.headers['Cache-Control']).to include 'public'
-        end
 
         it 'returns items with account\'s own replies' do
           json = body_as_json
@@ -87,9 +100,7 @@ RSpec.describe ActivityPub::RepliesController, type: :controller do
             expect(response.content_type).to eq 'application/activity+json'
           end
 
-          it 'returns public Cache-Control header' do
+          it_behaves_like 'cachable response'
-            expect(response.headers['Cache-Control']).to include 'public'
-          end
 
           context 'without only_other_accounts' do
             it 'returns items with account\'s own replies' do

spec/controllers/statuses_controller_spec.rb

@@ -5,6 +5,21 @@ require 'rails_helper'
 describe StatusesController do
   render_views
 
+  shared_examples 'cachable response' do
+    it 'does not set cookies' do
+      expect(response.cookies).to be_empty
+      expect(response.headers['Set-Cookies']).to be nil
+    end
+
+    it 'does not set sessions' do
+      expect(session).to be_empty
+    end
+
+    it 'returns public Cache-Control header' do
+      expect(response.headers['Cache-Control']).to include 'public'
+    end
+  end
+
   describe 'GET #show' do
     let(:account) { Fabricate(:account) }
     let(:status)  { Fabricate(:status, account: account) }
@@ -80,9 +95,7 @@ describe StatusesController do
           expect(response.headers['Vary']).to eq 'Accept'
         end
 
-        it 'returns public Cache-Control header' do
+        it_behaves_like 'cachable response'
-          expect(response.headers['Cache-Control']).to include 'public'
-        end
 
         it 'returns Content-Type header' do
           expect(response.headers['Content-Type']).to include 'application/activity+json'
@@ -470,9 +483,7 @@ describe StatusesController do
             expect(response.headers['Vary']).to eq 'Accept'
           end
 
-          it 'returns public Cache-Control header' do
+          it_behaves_like 'cachable response'
-            expect(response.headers['Cache-Control']).to include 'public'
-          end
 
           it 'returns Content-Type header' do
             expect(response.headers['Content-Type']).to include 'application/activity+json'