upgrades Zeitwerk to 2.1.4

This commit more or less undoes 9b5401f, restores autoloaded? not to
touch the descendants tracker, and autoloaded_constants because it is
documented in the guide.

3 files changed, 10 insertions, 12 deletions

diff --git a/activesupport/activesupport.gemspec b/activesupport/activesupport.gemspec
index dd2340cdd3..7ecbafc911 100644
--- a/activesupport/activesupport.gemspec
+++ b/activesupport/activesupport.gemspec
@@ -34,5 +34,5 @@ Gem::Specification.new do |s|
   s.add_dependency "tzinfo",          "~> 1.1"
   s.add_dependency "minitest",        "~> 5.1"
   s.add_dependency "concurrent-ruby", "~> 1.0", ">= 1.0.2"
-  s.add_dependency "zeitwerk",        "~> 2.1", ">= 2.1.2"
+  s.add_dependency "zeitwerk",        "~> 2.1", ">= 2.1.4"
 end
diff --git a/activesupport/lib/active_support/dependencies/zeitwerk_integration.rb b/activesupport/lib/active_support/dependencies/zeitwerk_integration.rb
index d5dc7c2ff4..fd39ad6e55 100644
--- a/activesupport/lib/active_support/dependencies/zeitwerk_integration.rb
+++ b/activesupport/lib/active_support/dependencies/zeitwerk_integration.rb
@@ -23,8 +23,13 @@ module ActiveSupport
           ActiveSupport::Inflector.safe_constantize(cpath)
         end
 
-        def to_unload?(cpath)
-          Rails.autoloaders.main.to_unload?(cpath)
+        def autoloaded_constants
+          Rails.autoloaders.main.unloadable_cpaths
+        end
+
+        def autoloaded?(object)
+          cpath = object.is_a?(Module) ? object.name : object.to_s
+          Rails.autoloaders.main.unloadable_cpath?(cpath)
         end
 
         def verbose=(verbose)
diff --git a/activesupport/lib/active_support/descendants_tracker.rb b/activesupport/lib/active_support/descendants_tracker.rb
index fe0c6991aa..21565138a7 100644
--- a/activesupport/lib/active_support/descendants_tracker.rb
+++ b/activesupport/lib/active_support/descendants_tracker.rb
@@ -22,18 +22,11 @@ module ActiveSupport
 
       def clear
         if defined? ActiveSupport::Dependencies
-          # to_unload? is only defined in Zeitwerk mode.
-          to_unload = if Dependencies.respond_to?(:to_unload?)
-            ->(klass) { Dependencies.to_unload?(klass.name) }
-          else
-            ->(klass) { Dependencies.autoloaded?(klass) }
-          end
-
           @@direct_descendants.each do |klass, descendants|
-            if to_unload[klass]
+            if Dependencies.autoloaded?(klass)
               @@direct_descendants.delete(klass)
             else
-              descendants.reject! { |v| to_unload[v] }
+              descendants.reject! { |v| Dependencies.autoloaded?(v) }
             end
           end
         else