Merge pull request rails#46111 from skipkayhil/generate-consistent-app-name

Make app_name consistent between new and update

Author: rafaelfranca

railties/lib/rails/generators/app_name.rb

@@ -7,7 +7,7 @@ module AppName # :nodoc:
 
       private
         def app_name
-          @app_name ||= original_app_name.tr("\\", "").tr("-. ", "_")
+          @app_name ||= original_app_name.parameterize(preserve_case: true).underscore
         end
 
         def original_app_name

railties/test/generators/app_generator_test.rb

@@ -470,6 +470,12 @@ def test_application_names_are_not_singularized
     assert_file "hats/config/environment.rb", /Rails\.application\.initialize!/
   end
 
+  def test_application_name_is_normalized_in_config
+    run_generator [File.join(destination_root, "MyWebSite"), "-d", "postgresql"]
+    assert_file "MyWebSite/app/views/layouts/application.html.erb", /<title>MyWebSite<\/title>/
+    assert_file "MyWebSite/config/database.yml", /my_web_site_production/
+  end
+
   def test_gemfile_has_no_whitespace_errors
     run_generator
     absolute = File.expand_path("Gemfile", destination_root)