depend on Zeitwerk 2.1.0

4 files changed, 20 insertions, 14 deletions

diff --git a/activesupport/CHANGELOG.md b/activesupport/CHANGELOG.md
index cf72673dbb..57e03b5e12 100644
--- a/activesupport/CHANGELOG.md
+++ b/activesupport/CHANGELOG.md
@@ -1,3 +1,11 @@
+*   The Zeitwerk compatibility interface for `ActiveSupport::Dependencies` no
+    longer implements `autoloaded_constants` or `autoloaded?` (undocumented,
+    anyway). Experience shows introspection does not have many use cases, and
+    troubleshooting is done by logging. With this design trade-off we are able
+    to use even less memory in all environments.
+
+    *Xavier Noria*
+
 *   Depends on Zeitwerk 2, which stores less metadata if reloading is disabled
     and hence uses less memory when `config.cache_classes` is `true`, a standard
     setup in production.
diff --git a/activesupport/activesupport.gemspec b/activesupport/activesupport.gemspec
index e719fc6176..546cc1797a 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",        "~> 2.0"
+  s.add_dependency "zeitwerk",        "~> 2.1"
 end
diff --git a/activesupport/lib/active_support/dependencies/zeitwerk_integration.rb b/activesupport/lib/active_support/dependencies/zeitwerk_integration.rb
index faf9edef27..b0f7a3f9cc 100644
--- a/activesupport/lib/active_support/dependencies/zeitwerk_integration.rb
+++ b/activesupport/lib/active_support/dependencies/zeitwerk_integration.rb
@@ -21,17 +21,8 @@ module ActiveSupport
           ActiveSupport::Inflector.safe_constantize(cpath)
         end
 
-        def autoloaded_constants
-          cpaths = []
-          Rails.autoloaders.each do |autoloader|
-            cpaths.concat(autoloader.loaded_cpaths.to_a)
-          end
-          cpaths
-        end
-
-        def autoloaded?(object)
-          cpath = object.is_a?(Module) ? object.name : object.to_s
-          Rails.autoloaders.any? { |autoloader| autoloader.loaded?(cpath) }
+        def to_unload?(cpath)
+          Rails.autoloaders.main.to_unload?(cpath)
         end
 
         def verbose=(verbose)
diff --git a/activesupport/lib/active_support/descendants_tracker.rb b/activesupport/lib/active_support/descendants_tracker.rb
index 2dca990712..fe0c6991aa 100644
--- a/activesupport/lib/active_support/descendants_tracker.rb
+++ b/activesupport/lib/active_support/descendants_tracker.rb
@@ -22,11 +22,18 @@ 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 ActiveSupport::Dependencies.autoloaded?(klass)
+            if to_unload[klass]
               @@direct_descendants.delete(klass)
             else
-              descendants.reject! { |v| ActiveSupport::Dependencies.autoloaded?(v) }
+              descendants.reject! { |v| to_unload[v] }
             end
           end
         else