Stop monkey-patching core classes

lib/tapioca/compilers/dsl/action_controller_helpers.rb

@@ -125,7 +125,7 @@ def decorate(root, constant)
 
         sig { override.returns(T::Enumerable[Module]) }
         def gather_constants
-          ::ActionController::Base.descendants.reject(&:abstract?).select(&:name)
+          descendants_of(::ActionController::Base).reject(&:abstract?).select(&:name)
         end
 
         private

lib/tapioca/compilers/dsl/action_mailer.rb

@@ -54,7 +54,7 @@ def decorate(root, constant)
 
         sig { override.returns(T::Enumerable[Module]) }
         def gather_constants
-          ::ActionMailer::Base.descendants.reject(&:abstract?)
+          descendants_of(::ActionMailer::Base).reject(&:abstract?)
         end
       end
     end

lib/tapioca/compilers/dsl/active_job.rb

@@ -67,7 +67,7 @@ def decorate(root, constant)
 
         sig { override.returns(T::Enumerable[Module]) }
         def gather_constants
-          ::ActiveJob::Base.descendants
+          descendants_of(::ActiveJob::Base)
         end
       end
     end

lib/tapioca/compilers/dsl/active_record_associations.rb

@@ -122,7 +122,7 @@ def decorate(root, constant)
 
         sig { override.returns(T::Enumerable[Module]) }
         def gather_constants
-          ActiveRecord::Base.descendants.reject(&:abstract_class?)
+          descendants_of(::ActiveRecord::Base).reject(&:abstract_class?)
         end
 
         private

lib/tapioca/compilers/dsl/active_record_columns.rb

@@ -127,7 +127,7 @@ def decorate(root, constant)
 
         sig { override.returns(T::Enumerable[Module]) }
         def gather_constants
-          ActiveRecord::Base.descendants.reject(&:abstract_class?)
+          descendants_of(::ActiveRecord::Base).reject(&:abstract_class?)
         end
 
         private

lib/tapioca/compilers/dsl/active_record_enum.rb

@@ -80,7 +80,7 @@ def decorate(root, constant)
 
         sig { override.returns(T::Enumerable[Module]) }
         def gather_constants
-          ::ActiveRecord::Base.descendants.reject(&:abstract_class?)
+          descendants_of(::ActiveRecord::Base).reject(&:abstract_class?)
         end
 
         private

lib/tapioca/compilers/dsl/active_record_scope.rb

@@ -68,7 +68,7 @@ def decorate(root, constant)
 
         sig { override.returns(T::Enumerable[Module]) }
         def gather_constants
-          ::ActiveRecord::Base.descendants.reject(&:abstract_class?)
+          descendants_of(::ActiveRecord::Base).reject(&:abstract_class?)
         end
 
         private

lib/tapioca/compilers/dsl/active_record_typed_store.rb

@@ -1,8 +1,6 @@
 # typed: strict
 # frozen_string_literal: true
 
-require "tapioca/core_ext/class"
-
 begin
   require "activerecord-typedstore"
 rescue LoadError
@@ -115,7 +113,7 @@ def decorate(root, constant)
 
         sig { override.returns(T::Enumerable[Module]) }
         def gather_constants
-          ::ActiveRecord::Base.descendants.select do |klass|
+          descendants_of(::ActiveRecord::Base).select do |klass|
             klass.include?(ActiveRecord::TypedStore::Behavior)
           end
         end

lib/tapioca/compilers/dsl/active_resource.rb

@@ -74,7 +74,7 @@ def decorate(root, constant)
 
         sig { override.returns(T::Enumerable[Module]) }
         def gather_constants
-          ::ActiveResource::Base.descendants
+          descendants_of(::ActiveResource::Base)
         end
 
         private

lib/tapioca/compilers/dsl/active_storage.rb

@@ -72,7 +72,7 @@ def decorate(root, constant)
 
         sig { override.returns(T::Enumerable[Module]) }
         def gather_constants
-          ActiveRecord::Base.descendants
+          descendants_of(::ActiveRecord::Base)
             .reject(&:abstract_class?)
             .grep(::ActiveStorage::Reflection::ActiveRecordExtensions::ClassMethods)
         end

lib/tapioca/compilers/dsl/active_support_current_attributes.rb

@@ -95,7 +95,7 @@ def decorate(root, constant)
 
         sig { override.returns(T::Enumerable[Module]) }
         def gather_constants
-          ::ActiveSupport::CurrentAttributes.descendants
+          descendants_of(::ActiveSupport::CurrentAttributes)
         end
 
         private

lib/tapioca/compilers/dsl/frozen_record.rb

@@ -86,7 +86,7 @@ def decorate(root, constant)
 
         sig { override.returns(T::Enumerable[Module]) }
         def gather_constants
-          ::FrozenRecord::Base.descendants.reject(&:abstract_class?)
+          descendants_of(::FrozenRecord::Base).reject(&:abstract_class?)
         end
       end
     end

lib/tapioca/compilers/dsl/identity_cache.rb

@@ -99,7 +99,7 @@ def decorate(root, constant)
 
         sig { override.returns(T::Enumerable[Module]) }
         def gather_constants
-          ::ActiveRecord::Base.descendants.select do |klass|
+          descendants_of(::ActiveRecord::Base).select do |klass|
             klass < ::IdentityCache::WithoutPrimaryIndex
           end
         end

lib/tapioca/compilers/dsl/state_machines.rb

@@ -1,8 +1,6 @@
 # typed: strict
 # frozen_string_literal: true
 
-require "tapioca/core_ext/class"
-
 begin
   require "state_machines"
 rescue LoadError

lib/tapioca/compilers/dsl_compiler.rb

@@ -62,12 +62,12 @@ def run(&blk)
         ).returns(T::Enumerable[Dsl::Base])
       end
       def gather_generators(requested_generators, excluded_generators)
-        generator_klasses = Dsl::Base.descendants.select do |klass|
+        generator_klasses = ::Tapioca::Reflection.descendants_of(Dsl::Base).select do |klass|
           (requested_generators.empty? || requested_generators.include?(klass)) &&
             !excluded_generators.include?(klass)
         end.sort_by { |klass| T.must(klass.name) }
 
-        T.cast(generator_klasses.map(&:new), T::Enumerable[Dsl::Base])
+        generator_klasses.map(&:new)
       end
 
       sig { params(requested_constants: T::Array[Module]).returns(T::Set[Module]) }

lib/tapioca/compilers/symbol_table/symbol_generator.rb

@@ -54,8 +54,8 @@ def symbols
         def engine_symbols(symbols)
           return Set.new unless Object.const_defined?("Rails::Engine")
 
-          engine = Object.const_get("Rails::Engine")
-            .descendants.reject(&:abstract_railtie?)
+          engine = descendants_of(Object.const_get("Rails::Engine"))
+            .reject(&:abstract_railtie?)
             .find do |klass|
               name = name_of(klass)
               !name.nil? && symbols.include?(name)

lib/tapioca/generator.rb

@@ -4,7 +4,6 @@
 require "pathname"
 require "thor"
 require "rake"
-require "tapioca/core_ext/string"
 
 module Tapioca
   class Generator < ::Thor::Shell::Color
@@ -372,7 +371,7 @@ def expected_rbis
 
     sig { params(constant_name: String).returns(Pathname) }
     def dsl_rbi_filename(constant_name)
-      config.outpath / "#{constant_name.underscore}.rbi"
+      config.outpath / "#{underscore(constant_name)}.rbi"
     end
 
     sig { params(gem_name: String, version: String).returns(Pathname) }
@@ -568,7 +567,7 @@ def compile_gem_rbi(gem)
     def compile_dsl_rbi(constant_name, contents, outpath: config.outpath, quiet: false)
       return if contents.nil?
 
-      rbi_name = constant_name.underscore + ".rbi"
+      rbi_name = underscore(constant_name) + ".rbi"
       filename = outpath / rbi_name
 
       out = String.new
@@ -702,5 +701,17 @@ def abort_if_pending_migrations!
       Rails.application.load_tasks
       Rake::Task["db:abort_if_pending_migrations"].invoke if Rake::Task.task_defined?("db:abort_if_pending_migrations")
     end
+
+    sig { params(class_name: String).returns(String) }
+    def underscore(class_name)
+      return class_name unless /[A-Z-]|::/.match?(class_name)
+
+      word = class_name.to_s.gsub("::", "/")
+      word.gsub!(/([A-Z\d]+)([A-Z][a-z])/, '\1_\2')
+      word.gsub!(/([a-z\d])([A-Z])/, '\1_\2')
+      word.tr!("-", "_")
+      word.downcase!
+      word
+    end
   end
 end

lib/tapioca/loader.rb

@@ -1,8 +1,6 @@
 # typed: strict
 # frozen_string_literal: true
 
-require "tapioca/core_ext/class"
-
 module Tapioca
   class Loader
     extend(T::Sig)
@@ -50,6 +48,7 @@ def require_helper(file)
     def rails_engines
       return [] unless Object.const_defined?("Rails::Engine")
 
+      # We can use `Class#descendants` here, since we know Rails is loaded
       Object.const_get("Rails::Engine").descendants.reject(&:abstract_railtie?)
     end
 

lib/tapioca/reflection.rb

@@ -105,5 +105,27 @@ def signature_of(method)
     def name_of_type(type)
       type.to_s.gsub(/\bAttachedClass\b/, "T.attached_class")
     end
+
+    # Returns an array with all classes that are < than the supplied class.
+    #
+    #   class C; end
+    #   descendants_of(C) # => []
+    #
+    #   class B < C; end
+    #   descendants_of(C) # => [B]
+    #
+    #   class A < B; end
+    #   descendants_of(C) # => [B, A]
+    #
+    #   class D < C; end
+    #   descendants_of(C) # => [B, A, D]
+    sig { type_parameters(:U).params(klass: T.type_parameter(:U)).returns(T::Array[T.type_parameter(:U)]) }
+    def descendants_of(klass)
+      result = ObjectSpace.each_object(klass.singleton_class).reject do |k|
+        T.cast(k, Module).singleton_class? || T.unsafe(k) == klass
+      end
+
+      T.unsafe(result)
+    end
   end
 end

spec/dsl_spec.rb

@@ -6,7 +6,6 @@
 require "content_helper"
 require "template_helper"
 require "isolation_helper"
-require "tapioca/core_ext/string"
 
 class DslSpec < Minitest::Spec
   extend T::Sig
@@ -46,7 +45,19 @@ def target_class_name
 
   sig { returns(String) }
   def target_class_file
-    target_class_name.underscore
+    underscore(target_class_name)
+  end
+
+  sig { params(class_name: String).returns(String) }
+  def underscore(class_name)
+    return class_name unless /[A-Z-]|::/.match?(class_name)
+
+    word = class_name.to_s.gsub("::", "/")
+    word.gsub!(/([A-Z\d]+)([A-Z][a-z])/, '\1_\2')
+    word.gsub!(/([a-z\d])([A-Z])/, '\1_\2')
+    word.tr!("-", "_")
+    word.downcase!
+    word
   end
 
   sig { params(str: String, indent: Integer).returns(String) }

tasks/generator_documentation.rake

@@ -2,7 +2,6 @@
 
 require "yard"
 require "tapioca"
-require "tapioca/core_ext/class"
 
 YARD::Rake::YardocTask.new(:yard_for_generate_documentation) do |task|
   task.files = ["lib/tapioca/compilers/dsl/**/*.rb"]