Remove channels from default app/ structure (rails#52344)

* Remove channels from default app/ structure

Now that Hotwire is the default, the majority of apps won't need custom
channels. And those that do can get the files back via the generator.

* Remove trailing space

* Remove additional needless elements

* No longer to be generated

* No longer generated

Author: dhh

guides/source/action_cable_overview.md

@@ -183,7 +183,8 @@ unsubscribing, or performing an action:
 
 A *channel* encapsulates a logical unit of work, similar to what a controller does in a
 typical MVC setup. By default, Rails creates a parent `ApplicationCable::Channel` class
-(which extends [`ActionCable::Channel::Base`][]) for encapsulating shared logic between your channels.
+(which extends [`ActionCable::Channel::Base`][]) for encapsulating shared logic between your channels,
+when you use the channel generator for the first time.
 
 #### Parent Channel Setup
 
@@ -195,8 +196,7 @@ module ApplicationCable
 end
 ```
 
-Then you would create your own channel classes. For example, you could have a
-`ChatChannel` and an `AppearanceChannel`:
+Your own channel classes could then look like these examples:
 
 ```ruby
 # app/channels/chat_channel.rb

railties/lib/rails/generators/rails/app/app_generator.rb

@@ -244,7 +244,6 @@ def test
       empty_directory_with_keep_file "test/helpers"
       empty_directory_with_keep_file "test/integration"
 
-      template "test/channels/application_cable/connection_test.rb"
       template "test/test_helper.rb"
     end
 
@@ -546,8 +545,6 @@ def delete_action_mailer_files_skipping_action_mailer
       def delete_action_cable_files_skipping_action_cable
         if options[:skip_action_cable]
           remove_dir "app/javascript/channels"
-          remove_dir "app/channels"
-          remove_dir "test/channels"
         end
       end
 

railties/lib/rails/generators/rails/app/templates/app/channels/application_cable/channel.rb.tt

@@ -71,7 +71,6 @@ def test_generator_if_skip_action_cable_is_given
     run_generator [destination_root, "--api", "--skip-action-cable"]
     assert_file "config/application.rb", /#\s+require\s+["']action_cable\/engine["']/
     assert_no_file "config/cable.yml"
-    assert_no_file "app/channels"
     assert_file "Gemfile" do |content|
       assert_no_match(/"redis"/, content)
     end
@@ -136,7 +135,6 @@ def default_files
         Rakefile
         Dockerfile
         config.ru
-        app/channels
         app/controllers
         app/mailers
         app/models

railties/lib/rails/generators/rails/app/templates/app/channels/application_cable/connection.rb.tt

@@ -19,8 +19,6 @@
   Rakefile
   app/assets/images/.keep
   app/assets/stylesheets/application.css
-  app/channels/application_cable/channel.rb
-  app/channels/application_cable/connection.rb
   app/controllers/application_controller.rb
   app/controllers/concerns/.keep
   app/helpers/application_helper.rb
@@ -72,7 +70,6 @@
   script/.keep
   storage/.keep
   test/application_system_test_case.rb
-  test/channels/application_cable/connection_test.rb
   test/controllers/.keep
   test/fixtures/files/.keep
   test/helpers/.keep
@@ -244,7 +241,6 @@ def test_app_update_does_not_generate_action_cable_contents_when_skip_action_cab
     assert_file "config/environments/production.rb" do |content|
       assert_no_match(/config\.action_cable/, content)
     end
-    assert_no_file "test/channels/application_cable/connection_test.rb"
   end
 
   def test_app_update_does_not_generate_bootsnap_contents_when_skip_bootsnap_is_given

railties/lib/rails/generators/rails/app/templates/test/channels/application_cable/connection_test.rb.tt

@@ -27,8 +27,6 @@
   test/dummy/Rakefile
   test/dummy/app/assets/images/.keep
   test/dummy/app/assets/stylesheets/application.css
-  test/dummy/app/channels/application_cable/channel.rb
-  test/dummy/app/channels/application_cable/connection.rb
   test/dummy/app/controllers/application_controller.rb
   test/dummy/app/controllers/concerns/.keep
   test/dummy/app/helpers/application_helper.rb

railties/test/generators/api_app_generator_test.rb

@@ -334,9 +334,6 @@ def test_generator_if_skip_action_cable_is_given
     run_generator [destination_root, "--skip-action-cable", "--webpack"]
     assert_file "#{application_path}/config/application.rb", /#\s+require\s+["']action_cable\/engine["']/
     assert_no_file "#{application_path}/config/cable.yml"
-    assert_no_file "#{application_path}/app/javascript/consumer.js"
-    assert_no_directory "#{application_path}/app/javascript/channels"
-    assert_no_directory "#{application_path}/app/channels"
     assert_file "Gemfile" do |content|
       assert_no_match(/"redis"/, content)
     end