Create AbstractCommand class

Library/Homebrew/abstract_command.rb

@@ -0,0 +1,42 @@
+# typed: strong
+# frozen_string_literal: true
+
+module Homebrew
+  class AbstractCommand
+    extend T::Helpers
+
+    abstract!
+
+    class << self
+      # registers subclasses for lookup by command name
+      sig { params(subclass: T.class_of(AbstractCommand)).void }
+      def inherited(subclass)
+        super
+        @cmds ||= T.let({}, T.nilable(T::Hash[String, T.class_of(AbstractCommand)]))
+        @cmds[subclass.command_name] = subclass
+      end
+
+      sig { params(name: String).returns(T.nilable(T.class_of(AbstractCommand))) }
+      def command(name) = @cmds&.[](name)
+
+      sig { returns(String) }
+      def command_name = T.must(name).split("::").fetch(-1).downcase
+    end
+
+    # @note because `Args` makes use `OpenStruct`, subclasses may need to use a tapioca compiler,
+    #   hash accessors, args.rbi, or other means to make this work with legacy commands:
+    sig { returns(Homebrew::CLI::Args) }
+    attr_reader :args
+
+    sig { void }
+    def initialize
+      @args = T.let(raw_args.parse, Homebrew::CLI::Args)
+    end
+
+    sig { abstract.returns(CLI::Parser) }
+    def raw_args; end
+
+    sig { abstract.void }
+    def run; end
+  end
+end

Library/Homebrew/brew.rb

@@ -59,6 +59,7 @@ begin
 
   ENV["PATH"] = path.to_s
 
+  require "abstract_command"
   require "commands"
   require "settings"
 
@@ -83,7 +84,12 @@ begin
   end
 
   if internal_cmd || Commands.external_ruby_v2_cmd_path(cmd)
-    Homebrew.send Commands.method_name(cmd)
+    cmd_class = Homebrew::AbstractCommand.command(T.must(cmd))
+    if cmd_class
+      cmd_class.new.run
+    else
+      Homebrew.public_send Commands.method_name(cmd)
+    end
   elsif (path = Commands.external_ruby_cmd_path(cmd))
     require?(path)
     exit Homebrew.failed? ? 1 : 0

Library/Homebrew/cmd/list.rb

@@ -1,6 +1,7 @@
 # typed: true
 # frozen_string_literal: true
 
+require "abstract_command"
 require "metafiles"
 require "formula"
 require "cli/parser"
@@ -8,10 +9,12 @@ require "cask/list"
 require "system_command"
 
 module Homebrew
-  extend SystemCommand::Mixin
+  module Cmd
+    class List < AbstractCommand
+      include SystemCommand::Mixin
 
-  sig { returns(CLI::Parser) }
-  def self.list_args
+      sig { override.returns(CLI::Parser) }
+      def raw_args
         Homebrew::CLI::Parser.new do
           description <<~EOS
             List all installed formulae and casks.
@@ -43,8 +46,8 @@ module Homebrew
                  description: "List formulae and/or casks in long format. " \
                               "Has no effect when a formula or cask name is passed as an argument."
           switch "-r",
-             description: "Reverse the order of the formulae and/or casks sort to list the oldest entries first. " \
-                          "Has no effect when a formula or cask name is passed as an argument."
+                 description: "Reverse the order of the formulae and/or casks sort to list the oldest entries " \
+                              "first. Has no effect when a formula or cask name is passed as an argument."
           switch "-t",
                  description: "Sort formulae and/or casks by time modified, listing most recently modified first. " \
                               "Has no effect when a formula or cask name is passed as an argument."
@@ -65,9 +68,8 @@ module Homebrew
         end
       end
 
-  def self.list
-    args = list_args.parse
-
+      sig { override.void }
+      def run
         if args.full_name?
           unless args.cask?
             formula_names = args.no_named? ? Formula.installed : args.named.to_resolved_formulae
@@ -81,23 +83,25 @@ module Homebrew
             else
               args.named.to_formulae_and_casks(only: :cask, method: :resolve)
             end
-        full_cask_names = cask_names.map(&:full_name).sort(&tap_and_name_comparison)
+            # The cast is because `Keg`` does not define `full_name`
+            full_cask_names = T.cast(cask_names, T::Array[T.any(Formula, Cask::Cask)])
+                               .map(&:full_name).sort(&tap_and_name_comparison)
             full_cask_names = Formatter.columns(full_cask_names) unless args.public_send(:"1?")
             puts full_cask_names if full_cask_names.present?
           end
-    elsif args.pinned?
+        elsif args[:pinned?]
           filtered_list(args:)
-    elsif args.versions?
+        elsif args[:versions?]
           filtered_list(args:) unless args.cask?
-      list_casks(args:) if args.cask? || (!args.formula? && !args.multiple? && args.no_named?)
+          list_casks(args:) if args.cask? || (!args.formula? && !args[:multiple?] && args.no_named?)
         elsif args.no_named?
           ENV["CLICOLOR"] = nil
 
           ls_args = []
-      ls_args << "-1" if args.public_send(:"1?")
-      ls_args << "-l" if args.l?
-      ls_args << "-r" if args.r?
-      ls_args << "-t" if args.t?
+          ls_args << "-1" if args[:"1?"]
+          ls_args << "-l" if args[:l?]
+          ls_args << "-r" if args[:r?]
+          ls_args << "-t" if args[:t?]
 
           if !args.cask? && HOMEBREW_CELLAR.exist? && HOMEBREW_CELLAR.children.any?
             ohai "Formulae" if $stdout.tty? && !args.formula?
@@ -122,7 +126,9 @@ module Homebrew
         end
       end
 
-  def self.filtered_list(args:)
+      private
+
+      def filtered_list(args:)
         names = if args.no_named?
           Formula.racks
         else
@@ -151,7 +157,7 @@ module Homebrew
         end
       end
 
-  def self.list_casks(args:)
+      def list_casks(args:)
         casks = if args.no_named?
           Cask::Caskroom.casks
         else
@@ -169,9 +175,9 @@ module Homebrew
           versions:  args.versions?,
         )
       end
-end
+    end
 
-class PrettyListing
+    class PrettyListing
       def initialize(path)
         Pathname.new(path).children.sort_by { |p| p.to_s.downcase }.each do |pn|
           case pn.basename.to_s
@@ -230,4 +236,6 @@ class PrettyListing
           puts "#{root}/ (#{files.length} #{other}files)"
         end
       end
+    end
+  end
 end

Library/Homebrew/test/cmd/list_spec.rb

@@ -1,12 +1,10 @@
 # frozen_string_literal: true
 
-require "cmd/shared_examples/args_parse"
+require "cmd/list"
 
-RSpec.describe "brew list" do
+RSpec.describe Homebrew::Cmd::List do
   let(:formulae) { %w[bar foo qux] }
 
-  it_behaves_like "parseable arguments"
-
   it "prints all installed Formulae", :integration_test do
     formulae.each do |f|
       (HOMEBREW_CELLAR/f/"1.0/somedir").mkpath