Don't choke when controller is not present in the request

lib/hotwire/spark/middleware.rb

@@ -6,8 +6,9 @@ def initialize(app)
   def call(env)
     status, headers, response = @app.call(env)
 
-    if html_response?(headers)
-      @request = ActionDispatch::Request.new(env)
+    @request = ActionDispatch::Request.new(env)
+
+    if interceptable_request? && html_response?(headers)
       html = html_from(response)
       html = inject_javascript(html)
       html = inject_options(html)
@@ -19,6 +20,10 @@ def call(env)
   end
 
   private
+    def interceptable_request?
+      @request.controller_instance.present?
+    end
+
     def html_response?(headers)
       headers["Content-Type"]&.include?("text/html")
     end

test/dummy/config/routes.rb

@@ -1,3 +1,5 @@
 Rails.application.routes.draw do
   root to: "home#show"
+
+  get "/redirected", to: redirect("/")
 end

test/middleware_test.rb

@@ -0,0 +1,7 @@
+require "application_system_test_case"
+
+class MiddlewareTest < ActionDispatch::IntegrationTest
+  test "error" do
+    get "/redirected"
+  end
+end