style: prefer __dir__ to __FILE__

See rails/rails@40bdbce1

Author: flavorjones

lib/generators/tailwindcss/controller/controller_generator.rb

@@ -3,7 +3,7 @@
 module Tailwindcss
   module Generators
     class ControllerGenerator < Erb::Generators::ControllerGenerator
-      source_root File.expand_path("../templates", __FILE__)
+      source_root File.expand_path("templates", __dir__)
     end
   end
 end

lib/generators/tailwindcss/mailer/mailer_generator.rb

@@ -3,7 +3,7 @@
 module Tailwindcss
   module Generators
     class MailerGenerator < Erb::Generators::MailerGenerator
-      source_root File.expand_path("../templates", __FILE__)
+      source_root File.expand_path("templates", __dir__)
     end
   end
 end

lib/generators/tailwindcss/scaffold/scaffold_generator.rb

@@ -6,7 +6,7 @@ module Generators
     class ScaffoldGenerator < Erb::Generators::ScaffoldGenerator
       include Rails::Generators::ResourceHelpers
 
-      source_root File.expand_path("../templates", __FILE__)
+      source_root File.expand_path("templates", __dir__)
 
       argument :attributes, type: :array, default: [], banner: "field:type field:type"