Move Async::Stop to lib/async/stop.rb and implement compatibility for older Ruby versions.

Author: ioquatix

lib/async/stop.rb

@@ -0,0 +1,82 @@
+# frozen_string_literal: true
+
+# Released under the MIT License.
+# Copyright, 2025, by Samuel Williams.
+
+require "fiber"
+require "console"
+
+module Async
+	# Raised when a task is explicitly stopped.
+	class Stop < Exception
+		# Represents the source of the stop operation.
+		class Cause < Exception
+			if RUBY_VERSION >= "3.4"
+				# @returns [Array(Thread::Backtrace::Location)] The backtrace of the caller.
+				def self.backtrace
+					caller_locations(2..-1)
+				end
+			else
+				# @returns [Array(String)] The backtrace of the caller.
+				def self.backtrace
+					caller(2..-1)
+				end
+			end
+			
+			# Create a new cause of the stop operation, with the given message.
+			#
+			# @parameter message [String] The error message.
+			# @returns [Cause] The cause of the stop operation.
+			def self.for(message = "Task was stopped")
+				instance = self.new(message)
+				instance.set_backtrace(self.backtrace)
+				return instance
+			end
+		end
+		
+		if RUBY_VERSION < "3.5"
+			# Create a new stop operation.
+			#
+			# This is a compatibility method for Ruby versions before 3.5 where cause is not propagated correctly when using {Fiber#raise}
+			#
+			# @parameter message [String | Hash] The error message or a hash containing the cause.
+			def initialize(message = "Task was stopped")
+				if message.is_a?(Hash)
+					@cause = message[:cause]
+					message = "Task was stopped"
+				end
+				
+				super(message)
+			end
+			
+			# @returns [Exception] The cause of the stop operation.
+			#
+			# This is a compatibility method for Ruby versions before 3.5 where cause is not propagated correctly when using {Fiber#raise}, we explicitly capture the cause here.
+			def cause
+				super || @cause
+			end
+		end
+		
+		# Used to defer stopping the current task until later.
+		class Later
+			# Create a new stop later operation.
+			#
+			# @parameter task [Task] The task to stop later.
+			# @parameter cause [Exception] The cause of the stop operation.
+			def initialize(task, cause = nil)
+				@task = task
+				@cause = cause
+			end
+			
+			# @returns [Boolean] Whether the task is alive.
+			def alive?
+				true
+			end
+			
+			# Transfer control to the operation - this will stop the task.
+			def transfer
+				@task.stop(false, cause: @cause)
+			end
+		end
+	end
+end

lib/async/task.rb

@@ -13,65 +13,11 @@
 
 require_relative "node"
 require_relative "condition"
+require_relative "stop"
 
 Fiber.attr_accessor :async_task
 
 module Async
-	# Raised when a task is explicitly stopped.
-	class Stop < Exception
-		# Represents the source of the stop operation.
-		class Cause < Exception
-			if RUBY_VERSION >= "3.4"
-				# @returns [Array(Thread::Backtrace::Location)] The backtrace of the caller.
-				def self.backtrace
-					caller_locations(2..-1)
-				end
-			else
-				# @returns [Array(String)] The backtrace of the caller.
-				def self.backtrace
-					caller(2..-1)
-				end
-			end
-			
-			# Create a new cause of the stop operation, with the given message.
-			#
-			# @parameter message [String] The error message.
-			# @returns [Cause] The cause of the stop operation.
-			def self.for(message = "Task was stopped")
-				instance = self.new(message)
-				instance.set_backtrace(self.backtrace)
-				return instance
-			end
-		end
-		
-		# Create a new stop operation.
-		def initialize(message = "Task was stopped")
-			super(message)
-		end
-		
-		# Used to defer stopping the current task until later.
-		class Later
-			# Create a new stop later operation.
-			#
-			# @parameter task [Task] The task to stop later.
-			# @parameter cause [Exception] The cause of the stop operation.
-			def initialize(task, cause = nil)
-				@task = task
-				@cause = cause
-			end
-			
-			# @returns [Boolean] Whether the task is alive.
-			def alive?
-				true
-			end
-			
-			# Transfer control to the operation - this will stop the task.
-			def transfer
-				@task.stop(false, cause: @cause)
-			end
-		end
-	end
-	
 	# Raised if a timeout occurs on a specific Fiber. Handled gracefully by `Task`.
 	# @public Since *Async v1*.
 	class TimeoutError < StandardError

test/async/task.rb

@@ -574,8 +574,6 @@
 		end
 
 		it "can stop a task from outside with a cause" do
-			skip_unless_minimum_ruby_version("3.5")
-			
 			error = nil
 
 			cause = RuntimeError.new("boom")