Ensure compatibility between ActionDispatch::Request::Session and Rack

Adding the `each` method is required for ensuring compatibility between
Rails, and other Rack frameworks (like Sinatra, etc.), that are mounted
within Rails, and wish to use its session tooling. Prior to this, there
was an inconsistency between ActionDispatch::Request::Session and
Rack::Session::Cookie, due to the absence of the `each` method. This
should hopefully fix that error. :)

For a full integration test with Sinatra and a standalone Rack
application, you can check out the gist for that here: https://gist.github.com/maclover7/08cd95b0bfe259465314311941326470.

Solves #15843.

1 files changed, 26 insertions, 0 deletions

diff --git a/actionpack/test/dispatch/request/session_test.rb b/actionpack/test/dispatch/request/session_test.rb
index 7dcbcc5c21..e022e7e21e 100644
--- a/actionpack/test/dispatch/request/session_test.rb
+++ b/actionpack/test/dispatch/request/session_test.rb
@@ -114,5 +114,31 @@ module ActionDispatch
         }.new
       end
     end
+
+    class SessionIntegrationTest < ActionDispatch::IntegrationTest
+      class MySessionApp
+        def call(env)
+          request = Rack::Request.new(env)
+          request.session['hello'] = 'Hello from MySessionApp!'
+          [ 200, {}, ['Hello from MySessionApp!'] ]
+        end
+      end
+
+      Router = ActionDispatch::Routing::RouteSet.new
+      Router.draw do
+        get '/mysessionapp' => MySessionApp.new
+      end
+
+      def app
+        @app ||= RoutedRackApp.new(Router)
+      end
+
+      def test_session_follows_rack_api_contract_1
+        get '/mysessionapp'
+        assert_response :ok
+        assert_equal 'Hello from MySessionApp!', @response.body
+        assert_equal 'Hello from MySessionApp!', session['hello']
+      end
+    end
   end
 end