Add ConnectionError with response.

async-websocket.gemspec

@@ -26,6 +26,7 @@ Gem::Specification.new do |spec|
 	spec.required_ruby_version = ">= 3.1"
 
 	spec.add_dependency "async-http", "~> 0.54"
+	spec.add_dependency "protocol-http", ">= 0.28.1"
 	spec.add_dependency "protocol-rack", "~> 0.5"
 	spec.add_dependency "protocol-websocket", "~> 0.15"
 end

lib/async/websocket/client.rb

@@ -110,9 +110,7 @@ def connect(authority, path, scheme: @delegate.scheme, headers: nil, handler: Co
 				response = request.call(connection)
 
 				unless response.stream?
-					response.close
-
-					raise ProtocolError, "Failed to negotiate connection: #{response.status}"
+					raise ConnectionError.new("Failed to negotiate connection!", response.unwrap)
 				end
 
 				protocol = response.headers[SEC_WEBSOCKET_PROTOCOL]&.first

lib/async/websocket/connect_request.rb

@@ -28,6 +28,10 @@ def close
 					@response.close
 				end
 
+				def unwrap
+					@response.buffered!
+				end
+
 				attr_accessor :response
 				attr_accessor :stream
 

lib/async/websocket/error.rb

@@ -15,5 +15,16 @@ class Error < ::Protocol::WebSocket::Error
 
 		class UnsupportedVersionError < Error
 		end
+
+		class ConnectionError < Error
+			def initialize(message, response)
+				super(message)
+
+				@response = response
+			end
+
+			# The failed HTTP response.
+			attr :response
+		end
 	end
 end

lib/async/websocket/upgrade_request.rb

@@ -33,6 +33,10 @@ def close
 					@response.close
 				end
 
+				def unwrap
+					@response.buffered!
+				end
+
 				attr_accessor :response
 
 				def stream?

test/async/websocket/client.rb

@@ -18,6 +18,8 @@
 				end
 
 				connection.close
+			rescue Protocol::WebSocket::ClosedError
+				# Ignore this error.
 			end or Protocol::HTTP::Response[404, {}, []]
 		end
 	end
@@ -125,7 +127,24 @@
 		it "raises an error when the server doesn't support websockets" do
 			expect do
 				Async::WebSocket::Client.connect(client_endpoint) {}
-			end.to raise_exception(Async::WebSocket::ProtocolError, message: be =~ /Failed to negotiate connection/)
+			end.to raise_exception(Async::WebSocket::ConnectionError, message: be =~ /Failed to negotiate connection/)
+		end
+	end
+
+	with 'deliberate failure response' do
+		let(:app) do
+			Protocol::HTTP::Middleware.for do |request|
+				Protocol::HTTP::Response[401, {}, ["You are not allowed!"]]
+			end
+		end
+
+		it "raises a connection error when the server responds with an error" do
+			begin
+				Async::WebSocket::Client.connect(client_endpoint) {}
+			rescue Async::WebSocket::ConnectionError => error
+				expect(error.response.status).to be == 401
+				expect(error.response.read).to be == "You are not allowed!"
+			end
 		end
 	end
 end
@@ -134,7 +153,7 @@
 	it 'raises an error' do
 		expect do
 			Async::WebSocket::Client.connect(client_endpoint) {}
-		end.to raise_exception(Async::WebSocket::ProtocolError, message: be =~ /Failed to negotiate connection/)
+		end.to raise_exception(Async::WebSocket::ConnectionError, message: be =~ /Failed to negotiate connection/)
 	end
 end