Make cmd_args block non-nilable

Library/Homebrew/abstract_command.rb

@@ -6,6 +6,7 @@ module Homebrew
   # module, because:
   # - Each Command lives in an isolated namespace.
   # - Each Command implements a defined interface.
+  # - `args` is available as an ivar, and thus does not need to be passed as an argument to helper methods.
   #
   # To subclass, implement a `run` method and provide a `cmd_args` block to document the command and its allowed args.
   # To generate method signatures for command args, run `brew typecheck --update`.
@@ -27,20 +28,21 @@ module Homebrew
 
       private
 
-      sig { params(block: T.nilable(T.proc.bind(CLI::Parser).void)).void }
+      sig { params(block: T.proc.bind(CLI::Parser).void).void }
       def cmd_args(&block)
         @parser = T.let(CLI::Parser.new(&block), T.nilable(CLI::Parser))
       end
     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(CLI::Args) }
     attr_reader :args
 
     sig { params(argv: T::Array[String]).void }
     def initialize(argv = ARGV.freeze)
-      @args = T.let(T.must(self.class.parser).parse(argv), CLI::Args)
+      parser = self.class.parser
+      raise "Commands must include a `cmd_args` block" if parser.nil?
+
+      @args = T.let(parser.parse(argv), CLI::Args)
     end
 
     sig { abstract.void }

Library/Homebrew/test/sorbet/tapioca/compilers/args_spec.rb

@@ -1,8 +1,7 @@
 # frozen_string_literal: true
 
-# require 'tapioca'
 require "tapioca/dsl"
-require_relative "../../../../sorbet/tapioca/compilers/args"
+require "sorbet/tapioca/compilers/args"
 
 RSpec.describe Tapioca::Compilers::Args do
   let(:compiler) { described_class.new(Tapioca::Dsl::Pipeline.new(requested_constants: []), RBI::Tree.new, Homebrew) }