Rack 2 should not use to_ary.

lib/protocol/rack/adapter.rb

@@ -3,7 +3,7 @@
 # Released under the MIT License.
 # Copyright, 2022-2026, by Samuel Williams.
 
-require "rack"
+require_relative "adapter/version"
 
 module Protocol
 	module Rack
@@ -16,9 +16,6 @@ module Rack
 		# response = adapter.call(request)
 		# ```
 		module Adapter
-			# The version of Rack being used. Can be overridden using the PROTOCOL_RACK_ADAPTER_VERSION environment variable.
-			VERSION = ENV.fetch("PROTOCOL_RACK_ADAPTER_VERSION", ::Rack.release)
-
 			if VERSION >= "3.1"
 				require_relative "adapter/rack31"
 				IMPLEMENTATION = Rack31

lib/protocol/rack/adapter/version.rb

@@ -0,0 +1,15 @@
+# frozen_string_literal: true
+
+# Released under the MIT License.
+# Copyright, 2022-2026, by Samuel Williams.
+
+require "rack"
+
+module Protocol
+	module Rack
+		module Adapter
+			# The version of Rack being used. Can be overridden using the PROTOCOL_RACK_ADAPTER_VERSION environment variable.
+			VERSION = ENV.fetch("PROTOCOL_RACK_ADAPTER_VERSION", ::Rack.release)
+		end
+	end
+end

lib/protocol/rack/body/enumerable.rb

@@ -7,6 +7,8 @@
 require "protocol/http/body/buffered"
 require "protocol/http/body/file"
 
+require_relative "../adapter/version"
+
 module Protocol
 	module Rack
 		module Body
@@ -17,18 +19,30 @@ class Enumerable < ::Protocol::HTTP::Body::Readable
 				# The content-length header key.
 				CONTENT_LENGTH = "content-length".freeze
 
-				# Wraps a Rack response body into an {Enumerable} instance.
-				# If the body is an Array, its total size is calculated automatically.
-				# 
-				# @parameter body [Object] The Rack response body that responds to `each`.
-				# @parameter length [Integer] Optional content length of the response body.
-				# @returns [Enumerable] A new enumerable body instance.
-				def self.wrap(body, length = nil)
-					if body.respond_to?(:to_ary)
-						# This avoids allocating an enumerator, which is more efficient:
-						return ::Protocol::HTTP::Body::Buffered.new(body.to_ary, length)
-					else
-						return self.new(body, length)
+				if Adapter::VERSION >= "3"
+					# Wraps a Rack response body into an {Enumerable} instance.
+					# If the body is an Array, its total size is calculated automatically.
+					# 
+					# @parameter body [Object] The Rack response body that responds to `each`.
+					# @parameter length [Integer] Optional content length of the response body.
+					# @returns [Enumerable] A new enumerable body instance.
+					def self.wrap(body, length = nil)
+						if body.respond_to?(:to_ary)
+							# This avoids allocating an enumerator, which is more efficient:
+							return ::Protocol::HTTP::Body::Buffered.new(body.to_ary, length)
+						else
+							return self.new(body, length)
+						end
+					end
+				else
+					def self.wrap(body, length = nil)
+						# Rack 2 does not specify or implement `to_ary` behaviour correctly, so the best we can do is check if it's an Array directly:
+						if body.is_a?(Array)
+							# This avoids allocating an enumerator, which is more efficient:
+							return ::Protocol::HTTP::Body::Buffered.new(body, length)
+						else
+							return self.new(body, length)
+						end
 					end
 				end
 

test/protocol/rack/body/enumerable.rb

@@ -77,4 +77,37 @@
 			end.to raise_exception(RuntimeError, message: be =~ /Bad Callable/)
 		end
 	end
+
+	with ".wrap with Rack::BodyProxy", if: defined?(Rack::BodyProxy) do
+		it "calls close on the body proxy" do
+			closed = false
+			rack_body = Rack::BodyProxy.new(["Hello", "World"]) do
+				closed = true
+			end
+
+			wrapped = subject.wrap(rack_body)
+
+			# Consume the body
+			chunks = []
+			wrapped.each{|chunk| chunks << chunk}
+
+			# The close callback should have been called
+			expect(closed).to be == true
+		end
+
+		it "calls close even when reading the body" do
+			closed = false
+			rack_body = Rack::BodyProxy.new(["Hello", "World"]) do
+				closed = true
+			end
+
+			wrapped = subject.wrap(rack_body)
+
+			# Read all chunks
+			wrapped.join
+
+			# The close callback should have been called
+			expect(closed).to be == true
+		end
+	end
 end