Support Duplex(io).

Author: samuel-williams-shopify

lib/io/stream.rb

@@ -9,18 +9,6 @@
 
 # @namespace
 class IO
-	# @namespace
-	module Stream
-		# Construct a buffered duplex stream from separate input and output endpoints.
-		# @parameter input [IO] The readable endpoint.
-		# @parameter output [IO] The writable endpoint.
-		# @parameter options [Hash] Additional options passed to the buffered stream wrapper.
-		# @returns [IO::Stream::Buffered] A buffered stream wrapping a duplex transport.
-		def self.Duplex(input, output = input, **options)
-			Buffered.wrap(Duplex.new(input, output), **options)
-		end
-	end
-	
 	# Convert any IO-like object into a buffered stream.
 	# @parameter io [IO] The IO object to wrap.
 	# @returns [IO::Stream::Buffered] A buffered stream wrapper.

lib/io/stream/duplex.rb

@@ -106,4 +106,17 @@ def wait_writable(duration = @timeout)
 			@output.wait_writable(duration)
 		end
 	end
+	
+	# Construct a buffered stream from either one duplex IO-like object or two separate endpoints.
+	# @parameter input [IO] The duplex IO object, or the readable endpoint.
+	# @parameter output [IO | Nil] The writable endpoint, when distinct from the readable endpoint.
+	# @parameter options [Hash] Additional options passed to the buffered stream wrapper.
+	# @returns [IO::Stream::Buffered] A buffered stream wrapping the supplied transport.
+	def self.Duplex(input, output = nil, **options)
+		if output
+			Buffered.wrap(Duplex.new(input, output), **options)
+		else
+			::IO.Stream(input)
+		end
+	end
 end

releases.md

@@ -1,5 +1,9 @@
 # Releases
 
+## Unreleased
+
+  - `IO::Stream::Duplex(io)` is equivalent to `IO::Stream(io)`.
+
 ## v0.12.0
 
   - Introduce `IO::Stream::Duplex` as a low-level duplex transport for composing separate input and output endpoints.

test/io/stream/buffered.rb

@@ -1073,8 +1073,8 @@ def after(error = nil)
 		server.sync_close = true
 
 		[
-			Async{server.accept},
-			Async{client.connect}
+			Async {server.accept},
+			Async {client.connect}
 		].each(&:wait)
 
 		@client = IO::Stream::Buffered.wrap(client)

test/io/stream/duplex.rb

@@ -35,6 +35,15 @@ def make_pipes
 	end
 
 	with "::Duplex" do
+		it "wraps a single duplex IO directly" do
+			io = StringIO.new
+			
+			stream = IO::Stream::Duplex(io)
+			
+			expect(stream).to be_a(IO::Stream::Buffered)
+			expect(stream.io).to be_equal(io)
+		end
+		
 		it "returns a buffered stream wrapping a duplex IO" do
 			pipes = make_pipes