More robust handling of Connection#close.

lib/protocol/websocket/connection.rb

@@ -55,12 +55,32 @@ def flush
 				@framer.flush
 			end
 
+			def open!
+				@state = :open
+
+				return self
+			end
+
+			def close!(...)
+				@state = :closed
+
+				return self
+			end
+
 			def closed?
 				@state == :closed
 			end
 
-			def close(code = Error::NO_ERROR, reason = "")
-				send_close(code, reason) unless closed?
+			def close(...)
+				unless @state == :closed
+					close!
+
+					begin
+						send_close(...)
+					rescue
+						# Ignore.
+					end
+				end
 
 				@framer.close
 			end
@@ -80,11 +100,11 @@ def read_frame
 
 				return frame
 			rescue ProtocolError => error
-				send_close(error.code, error.message)
+				close(error.code, error.message)
 
 				raise
 			rescue
-				send_close(Error::PROTOCOL_ERROR, $!.message)
+				close(Error::PROTOCOL_ERROR, $!.message)
 
 				raise
 			end
@@ -120,11 +140,13 @@ def receive_continuation(frame)
 			end
 
 			def receive_close(frame)
-				@state = :closed
-
 				code, reason = frame.unpack
 
-				send_close(code, reason)
+				# If we're already closed, then we don't need to send a close frame. Otherwise, according to the RFC, we should echo the close frame. However, it's possible it will fail to send if the connection is already closed.
+				unless @state == :closed
+					close!
+					send_close(code, reason)
+				end
 
 				if code and code != Error::NO_ERROR
 					raise ClosedError.new reason, code
@@ -142,18 +164,6 @@ def send_ping(data = "")
 				end
 			end
 
-			def open!
-				@state = :open
-
-				return self
-			end
-
-			def close!
-				@state = :closed
-
-				return self
-			end
-
 			def receive_ping(frame)
 				if @state != :closed
 					write_frame(frame.reply(mask: @mask))
@@ -198,8 +208,6 @@ def send_close(code = Error::NO_ERROR, reason = "")
 
 				self.write_frame(frame)
 				self.flush
-
-				@state = :closed
 			end
 
 			# Write a message to the connection.
@@ -237,7 +245,7 @@ def read(**options)
 					end
 				end
 			rescue ProtocolError => error
-				send_close(error.code, error.message)
+				close(error.code, error.message)
 
 				raise
 			end

test/protocol/websocket/connection.rb

@@ -15,12 +15,20 @@
 
 	let(:connection) {subject.new(server)}
 
-	it "can manipulate open/closed state" do
-		expect(connection).not.to be(:closed?)
-		connection.close!
-		expect(connection).to be(:closed?)
-		connection.open!
-		expect(connection).not.to be(:closed?)
+	with '#close!' do
+		it "can manipulate open/closed state" do
+			expect(connection).not.to be(:closed?)
+			connection.close!
+			expect(connection).to be(:closed?)
+			connection.open!
+			expect(connection).not.to be(:closed?)
+		end
+
+		it "ignores write failures" do
+			server.close
+			connection.close!
+			expect(connection).to be(:closed?)
+		end
 	end
 
 	it "doesn't generate mask by default" do
@@ -158,8 +166,8 @@
 
 			expect(connection).to be(:closed?)
 
-			# frame = client.read_frame
-			# expect(frame).to be_a(Protocol::WebSocket::CloseFrame)
+			frame = client.read_frame
+			expect(frame).to be_a(Protocol::WebSocket::CloseFrame)
 		end
 	end