Replace undef with prepended modules

Library/Homebrew/cli/args.rb

@@ -19,9 +19,6 @@ module Homebrew
       sig { returns(T::Array[String]) }
       attr_reader :options_only, :flags_only
 
-      # undefine tap to allow --tap argument
-      undef tap
-
       sig { void }
       def initialize
         require "cli/named_args"

Library/Homebrew/extend/os/linux/cleanup.rb

@@ -2,8 +2,10 @@
 # frozen_string_literal: true
 
 module Homebrew
-  class Cleanup
-    undef use_system_ruby?
+  module CleanupLinux
+    extend T::Helpers
+
+    requires_ancestor { Cleanup }
 
     sig { returns(T::Boolean) }
     def use_system_ruby?
@@ -21,3 +23,5 @@ module Homebrew
     end
   end
 end
+
+Homebrew::Cleanup.prepend(Homebrew::CleanupLinux)

Library/Homebrew/extend/os/linux/formula.rb

@@ -1,12 +1,10 @@
 # typed: true # rubocop:disable Sorbet/StrictSigil
 # frozen_string_literal: true
 
-class Formula
-  undef shared_library
-  undef loader_path
-  undef deuniversalize_machos
-  undef add_global_deps_to_spec
-  undef valid_platform?
+module FormulaLinux
+  extend T::Helpers
+
+  requires_ancestor { Formula }
 
   sig { params(name: String, version: T.nilable(T.any(String, Integer))).returns(String) }
   def shared_library(name, version = nil)
@@ -50,3 +48,5 @@ class Formula
     requirements.none?(MacOSRequirement)
   end
 end
+
+Formula.prepend(FormulaLinux)

Library/Homebrew/extend/os/linux/parser.rb

@@ -1,16 +1,19 @@
-# typed: strict
+# typed: true # rubocop:todo Sorbet/StrictSigil
 # frozen_string_literal: true
 
 module Homebrew
   module CLI
-    class Parser
-      undef set_default_options
-      undef validate_options
+    module ParserLinux
+      extend T::Helpers
 
+      requires_ancestor { Homebrew::CLI::Parser }
+
+      sig { void }
       def set_default_options
         @args["formula?"] = true if @args.respond_to?(:formula?)
       end
 
+      sig { void }
       def validate_options
         return unless @args.respond_to?(:cask?)
         return unless @args.cask?
@@ -22,3 +25,5 @@ module Homebrew
     end
   end
 end
+
+Homebrew::CLI::Parser.prepend(Homebrew::CLI::ParserLinux)

Library/Homebrew/extend/os/mac/cleaner.rb

@@ -1,13 +1,13 @@
 # typed: strict
 # frozen_string_literal: true
 
-class Cleaner
+module CleanerMac
   private
 
-  undef executable_path?
-
   sig { params(path: Pathname).returns(T::Boolean) }
   def executable_path?(path)
     path.mach_o_executable? || path.text_executable?
   end
 end
+
+Cleaner.prepend(CleanerMac)

Library/Homebrew/extend/os/mac/cleanup.rb

@@ -2,9 +2,7 @@
 # frozen_string_literal: true
 
 module Homebrew
-  class Cleanup
-    undef use_system_ruby?
-
+  module CleanupMac
     sig { returns(T::Boolean) }
     def use_system_ruby?
       return false if Homebrew::EnvConfig.force_vendor_ruby?
@@ -13,3 +11,5 @@ module Homebrew
     end
   end
 end
+
+Homebrew::Cleanup.prepend(Homebrew::CleanupMac)

Library/Homebrew/extend/os/mac/dev-cmd/bottle.rb

@@ -3,9 +3,7 @@
 
 module Homebrew
   module DevCmd
-    class Bottle < AbstractCommand
-      undef tar_args
-
+    module BottleMac
       sig { returns(T::Array[String]) }
       def tar_args
         if MacOS.version >= :catalina
@@ -15,8 +13,6 @@ module Homebrew
         end
       end
 
-      undef gnu_tar
-
       sig { params(gnu_tar_formula: Formula).returns(String) }
       def gnu_tar(gnu_tar_formula)
         "#{gnu_tar_formula.opt_bin}/gtar"
@@ -24,3 +20,5 @@ module Homebrew
     end
   end
 end
+
+Homebrew::DevCmd::Bottle.prepend(Homebrew::DevCmd::BottleMac)

Library/Homebrew/extend/os/mac/formula.rb

@@ -1,9 +1,10 @@
 # typed: strict
 # frozen_string_literal: true
 
-class Formula
-  undef valid_platform?
-  undef std_cmake_args
+module FormulaMac
+  extend T::Helpers
+
+  requires_ancestor { Formula }
 
   sig { returns(T::Boolean) }
   def valid_platform?
@@ -31,3 +32,5 @@ class Formula
     args
   end
 end
+
+Formula.prepend(FormulaMac)

Library/Homebrew/extend/os/mac/formula_installer.rb

@@ -1,8 +1,10 @@
 # typed: strict
 # frozen_string_literal: true
 
-class FormulaInstaller
-  undef fresh_install?
+module FormulaInstallerMac
+  extend T::Helpers
+
+  requires_ancestor { FormulaInstaller }
 
   sig { params(formula: Formula).returns(T.nilable(T::Boolean)) }
   def fresh_install?(formula)
@@ -10,3 +12,5 @@ class FormulaInstaller
       (!installed_as_dependency? || !formula.any_version_installed?)
   end
 end
+
+FormulaInstaller.prepend(FormulaInstallerMac)

Library/Homebrew/extend/os/mac/linkage_checker.rb

@@ -1,9 +1,7 @@
 # typed: strict
 # frozen_string_literal: true
 
-class LinkageChecker
-  undef system_libraries_exist_in_cache?
-
+module LinkageCheckerMac
   private
 
   sig { returns(T::Boolean) }
@@ -12,3 +10,5 @@ class LinkageChecker
     MacOS.version >= :big_sur
   end
 end
+
+LinkageChecker.prepend(LinkageCheckerMac)

Library/Homebrew/extend/os/mac/readall.rb

@@ -1,10 +1,12 @@
 # typed: strict
 # frozen_string_literal: true
 
-module Readall
-  class << self
-    undef valid_casks?
+module ReadallMac
+  extend T::Helpers
 
+  requires_ancestor { Kernel }
+
+  sig { params(tap: Tap, os_name: T.nilable(Symbol), arch: T.nilable(Symbol)).returns(T::Boolean) }
   def valid_casks?(tap, os_name: nil, arch: Hardware::CPU.type)
     return true if os_name == :linux
 
@@ -36,4 +38,5 @@ module Readall
     success
   end
 end
-end
+
+Readall.singleton_class.prepend(ReadallMac)

Library/Homebrew/extend/os/mac/simulate_system.rb

@@ -2,20 +2,17 @@
 # frozen_string_literal: true
 
 module Homebrew
-  class SimulateSystem
-    class << self
-      undef simulating_or_running_on_macos?
-      undef current_os
-
+  module SimulateSystemMac
     sig { returns(T::Boolean) }
     def simulating_or_running_on_macos?
-        os.blank? || [:macos, *MacOSVersion::SYMBOLS.keys].include?(os)
+      SimulateSystem.os.blank? || [:macos, *MacOSVersion::SYMBOLS.keys].include?(SimulateSystem.os)
     end
 
     sig { returns(Symbol) }
     def current_os
-        os || MacOS.version.to_sym
-      end
+      SimulateSystem.os || MacOS.version.to_sym
     end
   end
 end
+
+Homebrew::SimulateSystem.singleton_class.prepend(Homebrew::SimulateSystemMac)