refactor: allow controllers to override the app version

With this alone, the same Rails app could serve different Inertia apps,
setting a different version for each one in base controllers.

Author: ElMassimo

lib/inertia_rails/controller.rb

@@ -62,6 +62,10 @@ def inertia_view_assigns
 
     private
 
+    def inertia_configuration
+      ::InertiaRails.configuration
+    end
+
     def inertia_layout
       layout = ::InertiaRails.layout
 

lib/inertia_rails/middleware.rb

@@ -5,8 +5,7 @@ def initialize(app)
     end
 
     def call(env)
-      InertiaRailsRequest.new(@app, env)
-                         .response
+      InertiaRailsRequest.new(@app, env).response
     ensure
       ::InertiaRails.reset!
     end
@@ -60,11 +59,15 @@ def get?
         request_method == 'GET'
       end
 
+      def controller
+        @env["action_controller.instance"]
+      end
+
       def request_method
         @env['REQUEST_METHOD']
       end
 
-      def inertia_version
+      def client_version
         @env['HTTP_X_INERTIA_VERSION']
       end
 
@@ -73,17 +76,15 @@ def inertia_request?
       end
 
       def version_stale?
-        sent_version != saved_version
+        coerce_version(client_version) != coerce_version(server_version)
       end
 
-      def sent_version
-        return nil if inertia_version.nil?
-
-        InertiaRails.version.is_a?(Numeric) ? inertia_version.to_f : inertia_version
+      def server_version
+        controller.send(:inertia_configuration).version
       end
 
-      def saved_version
-        InertiaRails.version.is_a?(Numeric) ? InertiaRails.version.to_f : InertiaRails.version
+      def coerce_version(version)
+        server_version.is_a?(Numeric) ? version.to_f : version
       end
 
       def force_refresh(request)