Constant errors

session.go

@@ -1,7 +1,6 @@
 package melody
 
 import (
-	"errors"
 	"net/http"
 	"sync"
 	"time"
@@ -23,20 +22,20 @@ type Session struct {
 
 func (s *Session) writeMessage(message *envelope) {
 	if s.closed() {
-		s.melody.errorHandler(s, errors.New("tried to write to closed a session"))
+		s.melody.errorHandler(s, ErrWriteClosed)
 		return
 	}
 
 	select {
 	case s.output <- message:
 	default:
-		s.melody.errorHandler(s, errors.New("session message buffer is full"))
+		s.melody.errorHandler(s, ErrMessageBufferFull)
 	}
 }
 
 func (s *Session) writeRaw(message *envelope) error {
 	if s.closed() {
-		return errors.New("tried to write to a closed session")
+		return ErrWriteClosed
 	}
 
 	s.conn.SetWriteDeadline(time.Now().Add(s.melody.Config.WriteWait))
@@ -144,7 +143,7 @@ func (s *Session) readPump() {
 // Write writes message to session.
 func (s *Session) Write(msg []byte) error {
 	if s.closed() {
-		return errors.New("session is closed")
+		return ErrSessionClosed
 	}
 
 	s.writeMessage(&envelope{t: websocket.TextMessage, msg: msg})
@@ -155,7 +154,7 @@ func (s *Session) Write(msg []byte) error {
 // WriteBinary writes a binary message to session.
 func (s *Session) WriteBinary(msg []byte) error {
 	if s.closed() {
-		return errors.New("session is closed")
+		return ErrSessionClosed
 	}
 
 	s.writeMessage(&envelope{t: websocket.BinaryMessage, msg: msg})
@@ -166,7 +165,7 @@ func (s *Session) WriteBinary(msg []byte) error {
 // Close closes session.
 func (s *Session) Close() error {
 	if s.closed() {
-		return errors.New("session is already closed")
+		return ErrSessionClosed
 	}
 
 	s.writeMessage(&envelope{t: websocket.CloseMessage, msg: []byte{}})
@@ -178,7 +177,7 @@ func (s *Session) Close() error {
 // Use the FormatCloseMessage function to format a proper close message payload.
 func (s *Session) CloseWithMsg(msg []byte) error {
 	if s.closed() {
-		return errors.New("session is already closed")
+		return ErrSessionClosed
 	}
 
 	s.writeMessage(&envelope{t: websocket.CloseMessage, msg: msg})