Deprecate ActiveSupport::TimeWithZone.name

In c00f2d2 the `name` method was overridden to return 'Time' instead of
the real class name 'ActiveSupport::TimeWithZone'. The reasoning for
this is unclear and it can cause confusion for developers assuming that
name is returning the real class name. Since we don't know why this
was added, we're deprecating the method first to give developers a
chance to provide us with feedback and look to fix any issues that arise.

activesupport/CHANGELOG.md

@@ -1,3 +1,7 @@
+*   Deprecate `ActiveSupport::TimeWithZone.name` so that from Rails 7.1 it will use the default implementation.
+
+    *Andrew White*
+
 *   Tests parallelization is now disabled when running individual files to prevent the setup overhead.
 
     It can still be enforced if the environment variable `PARALLEL_WORKERS` is present and set to a value greater than 1.

activesupport/lib/active_support/time_with_zone.rb

@@ -40,6 +40,11 @@ module ActiveSupport
   class TimeWithZone
     # Report class name as 'Time' to thwart type checking.
     def self.name
+      ActiveSupport::Deprecation.warn(<<~EOM)
+        ActiveSupport::TimeWithZone.name has been deprecated and
+        from Rails 7.1 will use the default Ruby implementation.
+      EOM
+
       "Time"
     end
 

activesupport/test/core_ext/hash_ext_test.rb

@@ -585,12 +585,15 @@ class HashToXmlTest < ActiveSupport::TestCase
   end
 
   def test_timezoned_attributes
-    xml = {
-      created_at: Time.utc(1999, 2, 2),
-      local_created_at: Time.utc(1999, 2, 2).in_time_zone("Eastern Time (US & Canada)")
-    }.to_xml(@xml_options)
-    assert_match %r{<created-at type="dateTime">1999-02-02T00:00:00Z</created-at>}, xml
-    assert_match %r{<local-created-at type="dateTime">1999-02-01T19:00:00-05:00</local-created-at>}, xml
+    assert_deprecated("ActiveSupport::TimeWithZone.name has been deprecated") do
+      xml = {
+        created_at: Time.utc(1999, 2, 2),
+        local_created_at: Time.utc(1999, 2, 2).in_time_zone("Eastern Time (US & Canada)")
+      }.to_xml(@xml_options)
+
+      assert_match %r{<created-at type="dateTime">1999-02-02T00:00:00Z</created-at>}, xml
+      assert_match %r{<local-created-at type="dateTime">1999-02-01T19:00:00-05:00</local-created-at>}, xml
+    end
   end
 
   def test_multiple_records_from_xml_with_attributes_other_than_type_ignores_them_without_exploding

activesupport/test/core_ext/time_with_zone_test.rb

@@ -186,7 +186,9 @@ class TimeWithZoneTest < ActiveSupport::TestCase
       time: 1999-12-31 19:00:00.000000000 Z
     EOF
 
-    assert_equal(yaml, @twz.to_yaml)
+    assert_deprecated("ActiveSupport::TimeWithZone.name has been deprecated") do
+      assert_equal(yaml, @twz.to_yaml)
+    end
   end
 
   def test_ruby_to_yaml
@@ -199,7 +201,9 @@ class TimeWithZoneTest < ActiveSupport::TestCase
         time: 1999-12-31 19:00:00.000000000 Z
     EOF
 
-    assert_equal(yaml, { "twz" => @twz }.to_yaml)
+    assert_deprecated("ActiveSupport::TimeWithZone.name has been deprecated") do
+      assert_equal(yaml, { "twz" => @twz }.to_yaml)
+    end
   end
 
   def test_yaml_load
@@ -567,7 +571,9 @@ class TimeWithZoneTest < ActiveSupport::TestCase
   end
 
   def test_class_name
-    assert_equal "Time", ActiveSupport::TimeWithZone.name
+    assert_deprecated("ActiveSupport::TimeWithZone.name has been deprecated") do
+      assert_equal "Time", ActiveSupport::TimeWithZone.name
+    end
   end
 
   def test_method_missing_with_time_return_value