Merge pull request #32446 from sinsoku/add_dig_to_session

Add #dig to ActionDispatch::Request::Session

actionpack/lib/action_dispatch/request/session.rb

@@ -93,6 +93,14 @@ module ActionDispatch
         @delegate[key.to_s]
       end
 
+      # Returns the nested value specified by the sequence of key, returning
+      # nil if any intermediate step is nil.
+      def dig(*keys)
+        load_for_read!
+        keys = keys.map.with_index { |key, i| i.zero? ? key.to_s : key }
+        @delegate.dig(*keys)
+      end
+
       # Returns true if the session has the given key or false.
       def has_key?(key)
         load_for_read!

actionpack/test/dispatch/request/session_test.rb

@@ -118,6 +118,18 @@ module ActionDispatch
         end
       end
 
+      def test_dig
+        session = Session.create(store, req, {})
+        session["one"] = { "two" => "3" }
+
+        assert_equal "3", session.dig("one", "two")
+        assert_equal "3", session.dig(:one, "two")
+
+        assert_nil session.dig("three", "two")
+        assert_nil session.dig("one", "three")
+        assert_nil session.dig("one", :two)
+      end
+
       private
         def store
           Class.new {