Make time travel work with subclasses of Time/Date/Datetime

Closes #27614

Previously when calling `now` on a subclass of e.g. `Time` it would return an instance of `Time` instead of returning an instance of the subclass. This way, we always return the correct class.

2 files changed, 24 insertions, 5 deletions

diff --git a/activesupport/lib/active_support/testing/time_helpers.rb b/activesupport/lib/active_support/testing/time_helpers.rb
index e2f008b4b7..07c9be0604 100644
--- a/activesupport/lib/active_support/testing/time_helpers.rb
+++ b/activesupport/lib/active_support/testing/time_helpers.rb
@@ -10,7 +10,7 @@ module ActiveSupport
         @stubs = Concurrent::Map.new { |h, k| h[k] = {} }
       end
 
-      def stub_object(object, method_name, return_value)
+      def stub_object(object, method_name, &block)
         if stub = stubbing(object, method_name)
           unstub_object(stub)
         end
@@ -20,7 +20,7 @@ module ActiveSupport
         @stubs[object.object_id][method_name] = Stub.new(object, method_name, new_name)
 
         object.singleton_class.send :alias_method, new_name, method_name
-        object.define_singleton_method(method_name) { return_value }
+        object.define_singleton_method(method_name, &block)
       end
 
       def unstub_all!
@@ -134,9 +134,9 @@ module ActiveSupport
           now = date_or_time.to_time.change(usec: 0)
         end
 
-        simple_stubs.stub_object(Time, :now, now)
-        simple_stubs.stub_object(Date, :today, now.to_date)
-        simple_stubs.stub_object(DateTime, :now, now.to_datetime)
+        simple_stubs.stub_object(Time, :now) { at(now.to_i) }
+        simple_stubs.stub_object(Date, :today) { jd(now.to_date.jd) }
+        simple_stubs.stub_object(DateTime, :now) { jd(now.to_date.jd, now.hour, now.min, now.sec, Rational(now.utc_offset, 86400)) }
 
         if block_given?
           begin
diff --git a/activesupport/test/time_travel_test.rb b/activesupport/test/time_travel_test.rb
index c68be329bc..cfc6447360 100644
--- a/activesupport/test/time_travel_test.rb
+++ b/activesupport/test/time_travel_test.rb
@@ -3,6 +3,10 @@ require "active_support/core_ext/date_time"
 require "active_support/core_ext/numeric/time"
 
 class TimeTravelTest < ActiveSupport::TestCase
+  class TimeSubclass < ::Time; end
+  class DateSubclass < ::Date; end
+  class DateTimeSubclass < ::DateTime; end
+
   def test_time_helper_travel
     Time.stub(:now, Time.now) do
       begin
@@ -142,4 +146,19 @@ class TimeTravelTest < ActiveSupport::TestCase
       end
     end
   end
+
+  def test_time_helper_travel_with_time_subclass
+    assert_equal TimeSubclass, TimeSubclass.now.class
+    assert_equal DateSubclass, DateSubclass.today.class
+    assert_equal DateTimeSubclass, DateTimeSubclass.now.class
+
+    travel 1.day do
+      assert_equal TimeSubclass, TimeSubclass.now.class
+      assert_equal DateSubclass, DateSubclass.today.class
+      assert_equal DateTimeSubclass, DateTimeSubclass.now.class
+      assert_equal Time.now.to_s, TimeSubclass.now.to_s
+      assert_equal Date.today.to_s, DateSubclass.today.to_s
+      assert_equal DateTime.now.to_s, DateTimeSubclass.now.to_s
+    end
+  end
 end