Fix subscribed with no pattern to subscribe all messages

This is a regression for #36184.

And also, add new `monotonic` argument to the last of the method
signature rather than the first.

activesupport/lib/active_support/notifications.rb

@@ -231,18 +231,16 @@ module ActiveSupport
       #   ActiveSupport::Notifications.subscribe(/render/) do |event|
       #     @event = event
       #   end
-      def subscribe(*args, &block)
-        pattern, callback = *args
-        notifier.subscribe(pattern, callback, false, &block)
+      def subscribe(pattern = nil, callback = nil, &block)
+        notifier.subscribe(pattern, callback, monotonic: false, &block)
       end
 
-      def monotonic_subscribe(*args, &block)
-        pattern, callback = *args
-        notifier.subscribe(pattern, callback, true, &block)
+      def monotonic_subscribe(pattern = nil, callback = nil, &block)
+        notifier.subscribe(pattern, callback, monotonic: true, &block)
       end
 
-      def subscribed(callback, pattern, monotonic: false, &block)
-        subscriber = notifier.subscribe(pattern, callback, monotonic)
+      def subscribed(callback, pattern = nil, monotonic: false, &block)
+        subscriber = notifier.subscribe(pattern, callback, monotonic: monotonic)
         yield
       ensure
         unsubscribe(subscriber)

activesupport/lib/active_support/notifications/fanout.rb

@@ -20,8 +20,8 @@ module ActiveSupport
         super
       end
 
-      def subscribe(pattern = nil, callable = nil, monotonic = false, &block)
-        subscriber = Subscribers.new(monotonic, pattern, callable || block)
+      def subscribe(pattern = nil, callable = nil, monotonic: false, &block)
+        subscriber = Subscribers.new(pattern, callable || block, monotonic)
         synchronize do
           if String === pattern
             @string_subscribers[pattern] << subscriber
@@ -84,7 +84,7 @@ module ActiveSupport
       end
 
       module Subscribers # :nodoc:
-        def self.new(monotonic, pattern, listener)
+        def self.new(pattern, listener, monotonic)
           subscriber_class = monotonic ? MonotonicTimed : Timed
 
           if listener.respond_to?(:start) && listener.respond_to?(:finish)

activesupport/test/notifications_test.rb

@@ -113,6 +113,24 @@ module Notifications
       assert_equal expected, events
     end
 
+    def test_subscribed_all_messages
+      name     = "foo"
+      name2    = name * 2
+      expected = [name, name2, name]
+
+      events   = []
+      callback = lambda { |*_| events << _.first }
+      ActiveSupport::Notifications.subscribed(callback) do
+        ActiveSupport::Notifications.instrument(name)
+        ActiveSupport::Notifications.instrument(name2)
+        ActiveSupport::Notifications.instrument(name)
+      end
+      assert_equal expected, events
+
+      ActiveSupport::Notifications.instrument(name)
+      assert_equal expected, events
+    end
+
     def test_subscribing_to_instrumentation_while_inside_it
       # the repro requires that there are no evented subscribers for the "foo" event,
       # so we have to duplicate some of the setup code