Always subscribe to event objects via `AS::Notifications.subscribe`

We don't need to have a special subscribe method for objects.  The
regular `subscribe` method is more expensive than a specialized method,
but `subscribe` should not be called frequently.  If that turns out to
be a hotspot, we can introduce a specialized method.  :)

1 files changed, 16 insertions, 9 deletions

diff --git a/activesupport/test/notifications_test.rb b/activesupport/test/notifications_test.rb
index 119062d5bf..62817a839a 100644
--- a/activesupport/test/notifications_test.rb
+++ b/activesupport/test/notifications_test.rb
@@ -29,7 +29,7 @@ module Notifications
   class SubscribeEventObjects < TestCase
     def test_subscribe_events
       events = []
-      @notifier.subscribe_event do |event|
+      @notifier.subscribe do |event|
         events << event
       end
 
@@ -42,16 +42,23 @@ module Notifications
       assert_operator event.duration, :>, 0
     end
 
-    def test_subscribe_via_subscribe_method
-      events = []
-      @notifier.subscribe do |event|
-        events << event
+    def test_subscribe_via_top_level_api
+      old_notifier = ActiveSupport::Notifications.notifier
+      ActiveSupport::Notifications.notifier = ActiveSupport::Notifications::Fanout.new
+
+      event = nil
+      ActiveSupport::Notifications.subscribe("foo") do |e|
+        event = e
       end
 
-      ActiveSupport::Notifications.instrument("foo")
-      event = events.first
-      assert event, "should have an event"
-      assert_operator event.allocations, :>, 0
+      ActiveSupport::Notifications.instrument("foo") do
+        100.times { Object.new } # allocate at least 100 objects
+      end
+
+      assert event
+      assert_operator event.allocations, :>=, 100
+    ensure
+      ActiveSupport::Notifications.notifier = old_notifier
     end
   end