Search subclasses instead of using registry

Library/Homebrew/abstract_command.rb

@@ -1,8 +1,6 @@
 # typed: strong
 # frozen_string_literal: true
 
-require "command_registry"
-
 module Homebrew
   # Subclass this to implement a `brew` command. This is preferred to declaring a named function in the `Homebrew`
   # module, because:
@@ -22,19 +20,16 @@ module Homebrew
       sig { returns(String) }
       def command_name = T.must(name).split("::").fetch(-1).downcase
 
+      # @return the AbstractCommand subclass associated with the brew CLI command name.
+      sig { params(name: String).returns(T.nilable(T.class_of(AbstractCommand))) }
+      def command(name) = subclasses.find { _1.command_name == name }
+
       private
 
       sig { params(block: T.nilable(T.proc.bind(CLI::Parser).void)).void }
       def cmd_args(&block)
         @parser_block = T.let(block, T.nilable(T.proc.void))
       end
-
-      # registers subclasses for lookup by command name
-      sig { params(subclass: T.class_of(AbstractCommand)).void }
-      def inherited(subclass)
-        super
-        CommandRegistry.register(subclass)
-      end
     end
 
     # @note because `Args` makes use `OpenStruct`, subclasses may need to use a tapioca compiler,

Library/Homebrew/brew.rb

@@ -84,7 +84,7 @@ begin
   end
 
   if internal_cmd || Commands.external_ruby_v2_cmd_path(cmd)
-    cmd_class = Homebrew::CommandRegistry.command(T.must(cmd))
+    cmd_class = Homebrew::AbstractCommand.command(T.must(cmd))
     if cmd_class
       cmd_class.new.run
     else

Library/Homebrew/command_registry.rb

@@ -1,19 +0,0 @@
-# typed: strong
-# frozen_string_literal: true
-
-module Homebrew
-  module CommandRegistry
-    extend T::Helpers
-
-    Cmd = T.type_alias { T.class_of(AbstractCommand) } # rubocop:disable Style/MutableConstant
-
-    sig { params(subclass: Cmd).void }
-    def self.register(subclass)
-      @cmds ||= T.let({}, T.nilable(T::Hash[String, Cmd]))
-      @cmds[subclass.command_name] = subclass
-    end
-
-    sig { params(name: String).returns(T.nilable(Cmd)) }
-    def self.command(name) = @cmds&.[](name)
-  end
-end