Gracefully handle the new Rails default of "no system tests"

Fixes #585

Author: flavorjones

CHANGELOG.md

@@ -1,5 +1,12 @@
 # `tailwindcss-rails` Changelog
 
+## next / unreleased
+
+### Improved
+
+* Support Rails 8.1 scaffolding which disables system tests by default. #585 @flavorjones
+
+
 ## v4.3.0 / 2025-07-06
 
 ### Improved

lib/generators/test_unit/scaffold/scaffold_generator.rb

@@ -4,10 +4,9 @@ module TestUnit # :nodoc:
   module Generators # :nodoc:
     class ScaffoldGenerator < Base # :nodoc:
       def fix_system_test
-        if turbo_defined? && options[:system_tests]
-          gsub_file File.join("test/system", class_path, "#{file_name.pluralize}_test.rb"),
-                    /(click_on.*Destroy this.*)$/,
-                    "accept_confirm { \\1 }"
+        system_test_file = File.join("test/system", class_path, "#{file_name.pluralize}_test.rb")
+        if turbo_defined? && options[:system_tests] && File.exist?(system_test_file)
+          gsub_file(system_test_file, /(click_on.*Destroy this.*)$/, "accept_confirm { \\1 }")
         end
       end
 

test/integration/user_install_test.sh

@@ -69,8 +69,12 @@ if [[ $(rails -v) > "Rails 8.0.0.beta" ]] ; then
   grep -q PasswordsController app/controllers/passwords_controller.rb
 fi
 
+# TEST: doesn't fail when not generating system tests
+bin/rails generate scaffold memo title:string body:text published:boolean --system-tests=false
+grep -q "Show" app/views/memos/index.html.erb
+
 # TEST: presence of the generated file
-bin/rails generate scaffold post title:string body:text published:boolean
+bin/rails generate scaffold post title:string body:text published:boolean --system-tests=true
 grep -q "Show" app/views/posts/index.html.erb
 
 # TEST: the "accept_confirm" system test change was applied cleanly