Add stubs to TestProf's RuboCop plugin, and apply in tests

Library/.rubocop.yml

@@ -8,10 +8,11 @@ plugins:
       plugin_class_name: RuboCop::RSpec::Plugin
   - rubocop-sorbet:
       plugin_class_name: RuboCop::Sorbet::Plugin
+  - test-prof:
+      plugin_class_name: RuboCop::TestProf::Plugin
 
 require:
   - ./Homebrew/rubocops.rb
-  - test_prof/rubocop
 
 inherit_mode:
   merge:

Library/Homebrew/test/spec_helper.rb

@@ -31,6 +31,10 @@ Warnings.ignore :parser_syntax do
   require "rubocop"
 end
 
+# TODO: Remove this workaround once TestProf fixes their RuboCop plugin.
+# This is needed because the RuboCop RSpec plugin attempts to load TestProf's RuboCop plugin.
+require "utils/test_prof_rubocop_stub"
+
 require "rspec/github"
 require "rspec/retry"
 require "rspec/sorbet"

Library/Homebrew/utils/rubocop.rb

@@ -9,18 +9,7 @@ Warnings.ignore :parser_syntax do
   require "rubocop"
 end
 
-# TestProf is not able to detect what version of RuboCop we're using, so we need to manually import its cops.
-# For more details, see https://github.com/test-prof/test-prof/blob/v1.5.0/lib/test_prof/rubocop.rb
-Warnings.ignore(/TestProf cops require RuboCop >= 0.51.0 to run/) do
-  # All this file does is check the RuboCop version and require the files below.
-  # If we don't require this now while the warning is ignored, we'll see the warning again later
-  # when RuboCop requires the file.
-  require "test_prof/rubocop"
-
-  # This is copied from test-prof/rubocop.rb, and is necessary because that file returns early if the RuboCop version
-  # check isn't met.
-  require "test_prof/cops/plugin"
-  require "test_prof/cops/rspec/aggregate_examples"
-end
+# TODO: Remove this workaround once TestProf fixes their RuboCop plugin.
+require_relative "test_prof_rubocop_stub"
 
 exit RuboCop::CLI.new.run

Library/Homebrew/utils/test_prof_rubocop_stub.rb

@@ -0,0 +1,43 @@
+# typed: strict
+# frozen_string_literal: true
+
+require_relative "../warnings"
+
+# TestProf's RuboCop plugin has two issues that we need to work around:
+#
+# 1. It references RuboCop::TestProf::Plugin::VERSION, which does not exist.
+#    To solve this, we define the constant ourselves, which requires creating a dummy LintRoller::Plugin class.
+#    This should be fixed in the next version of TestProf.
+#    See: https://github.com/test-prof/test-prof/commit/a151a513373563ed8fa7f8e56193138d3ee9b5e3
+#
+# 2. It checks the RuboCop version using a method that is incompatible with our RuboCop setup.
+#    To bypass this check, we need to manually require the necessary files. More details below.
+
+module LintRoller
+  # Dummy class to satisfy TestProf's reference to LintRoller::Plugin.
+  class Plugin; end # rubocop:disable Lint/EmptyClass
+end
+
+module RuboCop
+  module TestProf
+    class Plugin < LintRoller::Plugin
+      VERSION = "1.5.0"
+    end
+  end
+end
+
+# TestProf is not able to detect what version of RuboCop we're using, so we need to manually import its cops.
+# For more details, see https://github.com/test-prof/test-prof/blob/v1.5.0/lib/test_prof/rubocop.rb
+# TODO: This will change in the next version of TestProf.
+#       See: https://github.com/test-prof/test-prof/commit/a151a513373563ed8fa7f8e56193138d3ee9b5e3
+Warnings.ignore(/TestProf cops require RuboCop >= 0.51.0 to run/) do
+  # All this file does is check the RuboCop version and require the files below.
+  # If we don't require this now while the warning is ignored, we'll see the warning again later
+  # when RuboCop requires the file.
+  require "test_prof/rubocop"
+
+  # This is copied from test-prof/rubocop.rb, and is necessary because that file returns early if the RuboCop version
+  # check isn't met.
+  require "test_prof/cops/plugin"
+  require "test_prof/cops/rspec/aggregate_examples"
+end