Add Async::Container::Generic#stopping?.

Author: samuel-williams-shopify

fixtures/async/container/a_container.rb

@@ -8,7 +8,8 @@
 module Async
 	module Container
 		AContainer = Sus::Shared("a container") do
-			let(:container) {subject.new}
+			let(:policy) {Async::Container::Policy::DEFAULT}
+			let(:container) {subject.new(policy: policy)}
 
 			with "#run" do
 				it "can run several instances concurrently" do
@@ -124,6 +125,21 @@ module Container
 			end
 
 			with "#stop" do
+				let(:policy) do
+					Class.new(Async::Container::Policy) do
+						def initialize
+							@events = []
+						end
+						
+						attr :events
+						
+						def child_exit(container, child, status, name:, key:, **options)
+							# Capture the state of `stopping?`:
+							@events << [:child_exit, container.stopping?]
+						end
+					end.new
+				end
+				
 				it "can gracefully stop the child process" do
 					container.spawn do
 						sleep(1)
@@ -132,13 +148,15 @@ module Container
 					end
 
 					expect(container).to be(:running?)
+					expect(container).not.to be(:stopping?)
 
 					# See above.
 					sleep 0.001
 
 					container.stop(true)
 
 					expect(container).not.to be(:running?)
+					expect(policy.events).to be == [[:child_exit, true]]
 				end
 
 				it "can forcefully stop the child process" do
@@ -156,6 +174,7 @@ module Container
 					container.stop(false)
 
 					expect(container).not.to be(:running?)
+					expect(policy.events).to be == [[:child_exit, true]]
 				end
 
 				it "can stop an uncooperative child process" do

lib/async/container/generic.rb

@@ -97,6 +97,12 @@ def running?
 				@group.running?
 			end
 
+			# Whether the container is currently stopping.
+			# @returns [Boolean]
+			def stopping?
+				!@running
+			end
+			
 			# Sleep until some state change occurs or the specified duration elapses.
 			#
 			# @parameter duration [Numeric] the maximum amount of time to sleep for.

releases.md

@@ -1,5 +1,9 @@
 # Releases
 
+## Unreleased
+
+  - Add `Async::Container::Generic#stopping?` so that policies can more accurately track the state of the container.
+
 ## v0.33.0
 
   - Add `Policy#make_statistics` to allow policies to customize statistics initialization.