Introduce 'ActiveSupport::Notifications::Fanout::Subscribers::MonotonicTimed' and 'ActiveSupport::Notifications::monotonic_subscribe'

Also, change the signature of ‘ActiveSupport::Notifications::Fanout#subscribe’ to accept optional ‘monotonic’ boolean argument. Then initialize either a ‘Timed’ or ‘MonotonicTimed’ subscriber based on the value of ‘monotonic’ parameter.

Introduce ‘ActiveSupport::Notifications::monotonic_subscribe’ method

Also, provision ‘ActiveSupport::Notifications::subscribed’ to optionally accept ‘monotonic’ boolean argument.

Update documentation for ActiveSupport::Notifications

Add tests

Update guides documentation under the 'Active Support Instrumentation' chapter

Incorporate feedback: use optional keyword argument to specify optional 'monotonic' option to 'subscribed' method

Fix a typo

1 files changed, 68 insertions, 1 deletions

diff --git a/activesupport/test/notifications_test.rb b/activesupport/test/notifications_test.rb
index d3c660a014..3b98749f1b 100644
--- a/activesupport/test/notifications_test.rb
+++ b/activesupport/test/notifications_test.rb
@@ -62,6 +62,38 @@ module Notifications
     end
   end
 
+  class TimedAndMonotonicTimedSubscriberTest < TestCase
+    def test_subscribe
+      event_name = "foo"
+      class_of_started = nil
+      class_of_finished = nil
+
+      ActiveSupport::Notifications.subscribe(event_name) do |name, started, finished, unique_id, data|
+        class_of_started = started.class
+        class_of_finished = finished.class
+      end
+
+      ActiveSupport::Notifications.instrument(event_name)
+
+      assert_equal [Time, Time], [class_of_started, class_of_finished]
+    end
+
+    def test_monotonic_subscribe
+      event_name = "foo"
+      class_of_started = nil
+      class_of_finished = nil
+
+      ActiveSupport::Notifications.monotonic_subscribe(event_name) do |name, started, finished, unique_id, data|
+        class_of_started = started.class
+        class_of_finished = finished.class
+      end
+
+      ActiveSupport::Notifications.instrument(event_name)
+
+      assert_equal [Float, Float], [class_of_started, class_of_finished]
+    end
+  end
+
   class SubscribedTest < TestCase
     def test_subscribed
       name     = "foo"
@@ -95,6 +127,42 @@ module Notifications
     ensure
       ActiveSupport::Notifications.notifier = old_notifier
     end
+
+    def test_timed_subscribed
+      event_name = "foo"
+      class_of_started = nil
+      class_of_finished = nil
+      callback = lambda do |name, started, finished, unique_id, data|
+        class_of_started = started.class
+        class_of_finished = finished.class
+      end
+
+      ActiveSupport::Notifications.subscribed(callback, event_name) do
+        ActiveSupport::Notifications.instrument(event_name)
+      end
+
+      ActiveSupport::Notifications.instrument(event_name)
+
+      assert_equal [Time, Time], [class_of_started, class_of_finished]
+    end
+
+    def test_monotonic_timed_subscribed
+      event_name = "foo"
+      class_of_started = nil
+      class_of_finished = nil
+      callback = lambda do |name, started, finished, unique_id, data|
+        class_of_started = started.class
+        class_of_finished = finished.class
+      end
+
+      ActiveSupport::Notifications.subscribed(callback, event_name, monotonic: true) do
+        ActiveSupport::Notifications.instrument(event_name)
+      end
+
+      ActiveSupport::Notifications.instrument(event_name)
+
+      assert_equal [Float, Float], [class_of_started, class_of_finished]
+    end
   end
 
   class UnsubscribeTest < TestCase
@@ -317,7 +385,6 @@ module Notifications
       assert_equal 0, event.cpu_time
     end
 
-
     def test_events_consumes_information_given_as_payload
       event = event(:foo, Concurrent.monotonic_time, Concurrent.monotonic_time + 1, random_id, payload: :bar)
       assert_equal Hash[payload: :bar], event.payload