Continue including Rails::ConsoleMethods to IRB's internal

Due to some users/libs relying on Rails::ConsoleMethod to extend Rails
console, we need to keep including it to IRB's internal.

But to prevent also adding `app` and `helper` methods to the console,
which are already registered to IRB through its API, we need to remove
them from the Rails::ConsoleMethods. Additionally, we should raise
deprecation warning when users try to use Rails::ConsoleMethods in this
way.

This commit:
- Removes all methods from Rails::ConsoleMethods that are already
  registered to IRB. So it's now essentially empty.
- Raises a deprecation warning when modules are included to Rails::ConsoleMethods
  or methods are added to it.
- Adds a test to ensure that the deprecation warning is raised and the
  methods are available in the console.

railties/lib/rails/commands/console/irb_console.rb

@@ -14,7 +14,7 @@ class ControllerHelper < RailsHelperBase
 
       # This method assumes an +ApplicationController+ exists, and that it extends ActionController::Base.
       def execute
-        helper
+        ApplicationController.helpers
       end
     end
 
@@ -23,23 +23,31 @@ class ControllerInstance < RailsHelperBase
 
       # This method assumes an +ApplicationController+ exists, and that it extends ActionController::Base.
       def execute
-        controller
+        @controller ||= ApplicationController.new
       end
     end
 
     class NewSession < RailsHelperBase
       description "Create a new session. If a block is given, the new session will be yielded to the block before being returned."
 
-      def execute
-        new_session
+      def execute(*)
+        app = Rails.application
+        session = ActionDispatch::Integration::Session.new(app)
+
+        # This makes app.url_for and app.foo_path available in the console
+        session.extend(app.routes.url_helpers)
+        session.extend(app.routes.mounted_helpers)
+
+        session
       end
     end
 
-    class AppInstance < RailsHelperBase
+    class AppInstance < NewSession
       description "Reference the global 'app' instance, created on demand. To recreate the instance, pass a non-false value as the parameter."
 
       def execute(create = false)
-        app(create)
+        @app_integration_instance = nil if create
+        @app_integration_instance ||= super
       end
     end
 
@@ -50,7 +58,8 @@ class Reloader < IRB::Command::Base
       description "Reloads the environment."
 
       def execute(*)
-        reload!
+        puts "Reloading..."
+        Rails.application.reloader.reload!
       end
     end
 
@@ -101,6 +110,10 @@ def start
           end
         end
 
+        # Because some users/libs use Rails::ConsoleMethods to extend Rails console,
+        # we still include it for backward compatibility.
+        IRB::ExtendCommandBundle.include ConsoleMethods
+
         # Respect user's choice of prompt mode.
         IRB.conf[:PROMPT_MODE] = :RAILS_PROMPT if IRB.conf[:PROMPT_MODE] == :DEFAULT
         IRB::Irb.new.run(IRB.conf)

railties/lib/rails/console/methods.rb

@@ -0,0 +1,23 @@
+# frozen_string_literal: true
+
+module Rails
+  module ConsoleMethods
+    def self.include(_mod, ...)
+      raise_deprecation_warning
+      super
+    end
+
+    def self.method_added(_method_name)
+      raise_deprecation_warning
+      super
+    end
+
+    def self.raise_deprecation_warning
+      ActiveSupport::Deprecation.new.warn(<<~MSG, caller_locations(1..1))
+        Extending Rails console through `Rails::ConsoleMethods` is deprecated and will be removed in Rails 7.3.
+        Please directly use IRB's extension API to add new commands or helpers to the console.
+        For more details, please visit: https://github.com/ruby/irb/blob/master/EXTEND_IRB.md
+      MSG
+    end
+  end
+end

railties/lib/rails/engine.rb

@@ -451,8 +451,7 @@ def initialize
     # Load console and invoke the registered hooks.
     # Check Rails::Railtie.console for more info.
     def load_console(app = self)
-      require "rails/console/app"
-      require "rails/console/helpers"
+      require "rails/console/methods"
       run_console_blocks(app)
       self
     end

railties/test/application/console_test.rb

@@ -184,6 +184,42 @@ def test_reload_command_fires_preparation_and_cleanup_callbacks
     write_prompt "c", "=> 3"
   end
 
+  def test_rails_console_methods_patch_backward_compatibility_with_module_inclusion
+    add_to_config <<-RUBY
+      module MyConsole
+        def foo
+          "this is foo"
+        end
+      end
+
+      console do
+        ::Rails::ConsoleMethods.include(MyConsole)
+      end
+    RUBY
+
+    spawn_console("-e development", wait_for_prompt: false)
+
+    assert_output "Extending Rails console through `Rails::ConsoleMethods` is deprecated", @primary, 30
+    write_prompt "foo", "=> \"this is foo\""
+  end
+
+  def test_rails_console_methods_patch_backward_compatibility_with_module_reopening
+    add_to_config <<-RUBY
+      console do
+        ::Rails::ConsoleMethods.module_eval do
+          def foo
+            "this is foo"
+          end
+        end
+      end
+    RUBY
+
+    spawn_console("-e development", wait_for_prompt: false)
+
+    assert_output "Extending Rails console through `Rails::ConsoleMethods` is deprecated", @primary, 30
+    write_prompt "foo", "=> \"this is foo\""
+  end
+
   def test_reload_command_reload_constants
     app_file "app/models/user.rb", <<-MODEL
       class User

railties/test/commands/console_test.rb

@@ -159,8 +159,7 @@ def config
         end
 
         def load_console
-          require "rails/console/app"
-          require "rails/console/helpers"
+          require "rails/console/methods"
         end
       end
       mocked_app.new(console)