update websocket lib, fix race on close (#33)

go.mod

@@ -3,7 +3,7 @@ module github.com/ccbrown/api-fu
 go 1.12
 
 require (
-	github.com/gorilla/websocket v1.4.0
+	github.com/gorilla/websocket v1.4.2
 	github.com/json-iterator/go v1.1.7
 	github.com/niemeyer/pretty v0.0.0-20200227124842-a10e7caefd8e // indirect
 	github.com/pkg/errors v0.8.1

go.sum

@@ -7,6 +7,8 @@ github.com/golang/protobuf v1.3.1/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5y
 github.com/google/gofuzz v1.0.0/go.mod h1:dBl0BpW6vV/+mYPU4Po3pmUjxk6FQPldtuIdl/M65Eg=
 github.com/gorilla/websocket v1.4.0 h1:WDFjx/TMzVgy9VdMMQi2K2Emtwi2QcUQsztZ/zLaH/Q=
 github.com/gorilla/websocket v1.4.0/go.mod h1:E7qHFY5m1UJ88s3WnNqhKjPHQ0heANvMoAMk2YaljkQ=
+github.com/gorilla/websocket v1.4.2 h1:+/TMaTYc4QFitKJxsQ7Yye35DkWvkdLcvGKqM+x0Ufc=
+github.com/gorilla/websocket v1.4.2/go.mod h1:YR8l580nyteQvAITg2hZ9XVh4b55+EU/adAjf1fMHhE=
 github.com/json-iterator/go v1.1.7 h1:KfgG9LzI+pYjr4xvmz/5H4FXjokeP+rlHLhv3iH62Fo=
 github.com/json-iterator/go v1.1.7/go.mod h1:KdQUCv79m/52Kvf8AW2vK1V8akMuk1QjK/uOdHXbAo4=
 github.com/konsorten/go-windows-terminal-sequences v1.0.1 h1:mweAR1A6xJ3oS2pRaGiHgQ4OO8tzTaLawm8vnODuwDk=

graphqlws/connection.go

@@ -244,14 +244,28 @@ func (c *Connection) writeLoop() {
 	for {
 		var msg *websocket.PreparedMessage
 		select {
-		case outgoing, ok := <-c.outgoing:
-			if !ok {
-				return
-			}
+		case outgoing := <-c.outgoing:
 			msg = outgoing
 		case <-keepAliveTicker.C:
 			msg = keepAlivePreparedMessage
 		case msg := <-c.closeMessage:
+			// make sure we send any outgoing messages before closing (e.g. to make sure we send
+			// back the error after a bad init)
+			for done := false; !done; {
+				select {
+				case msg := <-c.outgoing:
+					c.conn.SetWriteDeadline(time.Now().Add(time.Second))
+					if err := c.conn.WritePreparedMessage(msg); err != nil {
+						if !websocket.IsCloseError(err, websocket.CloseAbnormalClosure, websocket.CloseGoingAway) && err != websocket.ErrCloseSent {
+							c.Logger.Error(errors.Wrap(err, "websocket write error"))
+						}
+						done = true
+					}
+				default:
+					done = true
+				}
+			}
+
 			// initiate the close handshake
 			if err := c.conn.WriteMessage(websocket.CloseMessage, msg); err != nil {
 				c.Logger.Error(errors.Wrap(err, "websocket control write error"))