From 4cb6a7db875e793f2cc86169c3b65815f9779d82 Mon Sep 17 00:00:00 2001
From: Samuel Williams <samuel.williams@shopify.com>
Date: Tue, 4 Aug 2026 21:06:56 +1200
Subject: [PATCH] Add IO conversion for readable bodies.

---
 lib/protocol/http/body/readable.rb  |  8 ++++++++
 lib/protocol/http/body/stream.rb    | 22 +++++++++++++---------
 releases.md                         |  5 +++++
 test/protocol/http/body/readable.rb | 16 ++++++++++++++++
 4 files changed, 42 insertions(+), 9 deletions(-)

diff --git a/lib/protocol/http/body/readable.rb b/lib/protocol/http/body/readable.rb
index 21b04b0c..aa03731b 100644
--- a/lib/protocol/http/body/readable.rb
+++ b/lib/protocol/http/body/readable.rb
@@ -4,6 +4,8 @@
 # Copyright, 2019-2024, by Samuel Williams.
 # Copyright, 2023, by Bruno Sutic.
 
+require_relative "stream"
+
 module Protocol
 	module HTTP
 		module Body
@@ -186,6 +188,12 @@ def as_json(...)
 				def to_json(...)
 					as_json.to_json(...)
 				end
+				
+				# Return an IO-compatible stream for reading this body.
+				# @returns [Stream] The IO-compatible stream adapter.
+				def to_io
+					return Stream.new(self)
+				end
 			end
 		end
 	end
diff --git a/lib/protocol/http/body/stream.rb b/lib/protocol/http/body/stream.rb
index 6e3da3d8..72ba02e9 100644
--- a/lib/protocol/http/body/stream.rb
+++ b/lib/protocol/http/body/stream.rb
@@ -5,8 +5,6 @@
 # Copyright, 2023, by Genki Takiuchi.
 # Copyright, 2025, by William T. Nelson.
 
-require_relative "buffered"
-
 module Protocol
 	module HTTP
 		module Body
@@ -17,13 +15,15 @@ class Stream
 				
 				# Initialize the stream with the given input and output.
 				#
-				# @parameter input [Readable] The input stream.
-				# @parameter output [Writable] The output stream.
-				def initialize(input = nil, output = Buffered.new)
+				# @parameter input [Readable | Nil] The input stream.
+				# @parameter output [Writable | Nil] The output stream.
+				def initialize(input = nil, output = nil)
 					@input = input
 					@output = output
 					
-					raise ArgumentError, "Non-writable output!" unless output.respond_to?(:write)
+					if @output
+						raise ArgumentError, "Non-writable output!" unless output.respond_to?(:write)
+					end
 					
 					# Will hold remaining data in `#read`.
 					@buffer = nil
@@ -32,10 +32,10 @@ def initialize(input = nil, output = Buffered.new)
 					@closed_read = false
 				end
 				
-				# @attribute [Readable] The input stream.
+				# @attribute [Readable | Nil] The input stream.
 				attr :input
 				
-				# @attribute [Writable] The output stream.
+				# @attribute [Writable | Nil] The output stream.
 				attr :output
 				
 				# This provides a read-only interface for data, which is surprisingly tricky to implement correctly.
@@ -409,7 +409,11 @@ def inspect
 				
 				# @returns [Boolean] Whether there are any output chunks remaining.
 				def empty?
-					@output.empty?
+					if @output
+						return @output.empty?
+					else
+						return true
+					end
 				end
 				
 				private
diff --git a/releases.md b/releases.md
index 3e1ae536..2b65ddf9 100644
--- a/releases.md
+++ b/releases.md
@@ -1,5 +1,10 @@
 # Releases
 
+## Unreleased
+
+  - Add `Protocol::HTTP::Body::Readable#to_io` for obtaining an IO-compatible stream adapter.
+  - Avoid creating an implicit buffered output for `Protocol::HTTP::Body::Stream`.
+
 ## v0.68.0
 
   - Add HTTP status descriptions.
diff --git a/test/protocol/http/body/readable.rb b/test/protocol/http/body/readable.rb
index 0cb4c997..f5cb9e6f 100644
--- a/test/protocol/http/body/readable.rb
+++ b/test/protocol/http/body/readable.rb
@@ -9,6 +9,22 @@
 describe Protocol::HTTP::Body::Readable do
 	let(:body) {subject.new}
 	
+	with "#to_io" do
+		let(:body) {Protocol::HTTP::Body::Buffered.new(["Hello", "World"])}
+		
+		it "returns an IO-compatible stream" do
+			stream = body.to_io
+			
+			expect(stream).to be_a(Protocol::HTTP::Body::Stream)
+			expect(stream.output).to be_nil
+			expect(body.to_io).not.to be_equal(stream)
+			expect(stream.read(5)).to be == "Hello"
+			expect(stream.read(5)).to be == "World"
+			expect(stream.read(5)).to be_nil
+			expect{stream.write("!")}.to raise_exception(IOError)
+		end
+	end
+	
 	it "might not be empty" do
 		expect(body).not.to be(:empty?)
 	end