brew/Library/Homebrew/cmd/leaves.rb

# typed: true
# frozen_string_literal: true

require "abstract_command"
require "formula"
require "cask_dependent"

module Homebrew
  module Cmd
    class Leaves < AbstractCommand
      cmd_args do
        description <<~EOS
          List installed formulae that are not dependencies of another installed formula or cask.
        EOS
        switch "-r", "--installed-on-request",
               description: "Only list leaves that were manually installed."
        switch "-p", "--installed-as-dependency",
               description: "Only list leaves that were installed as dependencies."

        conflicts "--installed-on-request", "--installed-as-dependency"

        named_args :none
      end

      sig { override.void }
      def run
        leaves_list = Formula.installed - Formula.installed.flat_map(&:runtime_formula_dependencies)
        casks_runtime_dependencies = Cask::Caskroom.casks.flat_map do |cask|
          CaskDependent.new(cask).runtime_dependencies.map(&:to_formula)
        end
        leaves_list -= casks_runtime_dependencies
        leaves_list.select! { installed_on_request?(_1) } if args.installed_on_request?
        leaves_list.select! { installed_as_dependency?(_1) } if args.installed_as_dependency?

        leaves_list.map(&:full_name)
                   .sort
                   .each { puts(_1) }
      end

      private

      def installed_on_request?(formula)
        Tab.for_keg(formula.any_installed_keg).installed_on_request
      end

      def installed_as_dependency?(formula)
        Tab.for_keg(formula.any_installed_keg).installed_as_dependency
      end
    end
  end
end