close.go: Drop support for Go 1.13

close.go

@@ -8,6 +8,7 @@ import (
 	"encoding/binary"
 	"errors"
 	"fmt"
+	"net"
 	"time"
 
 	"nhooyr.io/websocket/internal/errd"
@@ -107,7 +108,7 @@ func (c *Conn) CloseNow() (err error) {
 	defer errd.Wrap(&err, "failed to close WebSocket")
 
 	if c.isClosed() {
-		return errClosed
+		return net.ErrClosed
 	}
 
 	c.close(nil)
@@ -124,7 +125,7 @@ func (c *Conn) closeHandshake(code StatusCode, reason string) (err error) {
 		return writeErr
 	}
 
-	if CloseStatus(closeHandshakeErr) == -1 && !errors.Is(errClosed, closeHandshakeErr) {
+	if CloseStatus(closeHandshakeErr) == -1 && !errors.Is(net.ErrClosed, closeHandshakeErr) {
 		return closeHandshakeErr
 	}
 
@@ -137,7 +138,7 @@ func (c *Conn) writeClose(code StatusCode, reason string) error {
 	c.wroteClose = true
 	c.closeMu.Unlock()
 	if wroteClose {
-		return errClosed
+		return net.ErrClosed
 	}
 
 	ce := CloseError{

close_go113.go

-//go:build !go1.16 && !js
-
-package websocket
-
-import (
-	"errors"
-)
-
-var errClosed = errors.New("use of closed network connection")

close_go116.go

-//go:build go1.16 && !js
-
-package websocket
-
-import (
-	"net"
-)
-
-var errClosed = net.ErrClosed

conn.go

@@ -9,6 +9,7 @@ import (
 	"errors"
 	"fmt"
 	"io"
+	"net"
 	"runtime"
 	"strconv"
 	"sync"
@@ -228,7 +229,7 @@ func (c *Conn) ping(ctx context.Context, p string) error {
 
 	select {
 	case <-c.closed:
-		return errClosed
+		return net.ErrClosed
 	case <-ctx.Done():
 		err := fmt.Errorf("failed to wait for pong: %w", ctx.Err())
 		c.close(err)
@@ -266,7 +267,7 @@ func (m *mu) tryLock() bool {
 func (m *mu) lock(ctx context.Context) error {
 	select {
 	case <-m.c.closed:
-		return errClosed
+		return net.ErrClosed
 	case <-ctx.Done():
 		err := fmt.Errorf("failed to acquire lock: %w", ctx.Err())
 		m.c.close(err)
@@ -279,7 +280,7 @@ func (m *mu) lock(ctx context.Context) error {
 		case <-m.c.closed:
 			// Make sure to release.
 			m.unlock()
-			return errClosed
+			return net.ErrClosed
 		default:
 		}
 		return nil

export_test.go

@@ -3,7 +3,11 @@
 
 package websocket
 
-import "nhooyr.io/websocket/internal/util"
+import (
+	"net"
+
+	"nhooyr.io/websocket/internal/util"
+)
 
 func (c *Conn) RecordBytesWritten() *int {
 	var bytesWritten int
@@ -24,7 +28,7 @@ func (c *Conn) RecordBytesRead() *int {
 	return &bytesRead
 }
 
-var ErrClosed = errClosed
+var ErrClosed = net.ErrClosed
 
 var ExportedDial = dial
 var SecWebSocketAccept = secWebSocketAccept

read.go

@@ -9,6 +9,7 @@ import (
 	"errors"
 	"fmt"
 	"io"
+	"net"
 	"strings"
 	"time"
 
@@ -206,7 +207,7 @@ func (c *Conn) readLoop(ctx context.Context) (header, error) {
 func (c *Conn) readFrameHeader(ctx context.Context) (header, error) {
 	select {
 	case <-c.closed:
-		return header{}, errClosed
+		return header{}, net.ErrClosed
 	case c.readTimeout <- ctx:
 	}
 
@@ -214,7 +215,7 @@ func (c *Conn) readFrameHeader(ctx context.Context) (header, error) {
 	if err != nil {
 		select {
 		case <-c.closed:
-			return header{}, errClosed
+			return header{}, net.ErrClosed
 		case <-ctx.Done():
 			return header{}, ctx.Err()
 		default:
@@ -225,7 +226,7 @@ func (c *Conn) readFrameHeader(ctx context.Context) (header, error) {
 
 	select {
 	case <-c.closed:
-		return header{}, errClosed
+		return header{}, net.ErrClosed
 	case c.readTimeout <- context.Background():
 	}
 
@@ -235,7 +236,7 @@ func (c *Conn) readFrameHeader(ctx context.Context) (header, error) {
 func (c *Conn) readFramePayload(ctx context.Context, p []byte) (int, error) {
 	select {
 	case <-c.closed:
-		return 0, errClosed
+		return 0, net.ErrClosed
 	case c.readTimeout <- ctx:
 	}
 
@@ -243,7 +244,7 @@ func (c *Conn) readFramePayload(ctx context.Context, p []byte) (int, error) {
 	if err != nil {
 		select {
 		case <-c.closed:
-			return n, errClosed
+			return n, net.ErrClosed
 		case <-ctx.Done():
 			return n, ctx.Err()
 		default:
@@ -255,7 +256,7 @@ func (c *Conn) readFramePayload(ctx context.Context, p []byte) (int, error) {
 
 	select {
 	case <-c.closed:
-		return n, errClosed
+		return n, net.ErrClosed
 	case c.readTimeout <- context.Background():
 	}
 

write.go

@@ -11,6 +11,7 @@ import (
 	"errors"
 	"fmt"
 	"io"
+	"net"
 	"time"
 
 	"compress/flate"
@@ -262,14 +263,14 @@ func (c *Conn) writeFrame(ctx context.Context, fin bool, flate bool, opcode opco
 		case <-ctx.Done():
 			return 0, ctx.Err()
 		case <-c.closed:
-			return 0, errClosed
+			return 0, net.ErrClosed
 		}
 	}
 	defer c.writeFrameMu.unlock()
 
 	select {
 	case <-c.closed:
-		return 0, errClosed
+		return 0, net.ErrClosed
 	case c.writeTimeout <- ctx:
 	}
 
@@ -277,7 +278,7 @@ func (c *Conn) writeFrame(ctx context.Context, fin bool, flate bool, opcode opco
 		if err != nil {
 			select {
 			case <-c.closed:
-				err = errClosed
+				err = net.ErrClosed
 			case <-ctx.Done():
 				err = ctx.Err()
 			default:
@@ -327,7 +328,7 @@ func (c *Conn) writeFrame(ctx context.Context, fin bool, flate bool, opcode opco
 		if opcode == opClose {
 			return n, nil
 		}
-		return n, errClosed
+		return n, net.ErrClosed
 	case c.writeTimeout <- context.Background():
 	}
 

ws_js.go

@@ -6,6 +6,7 @@ import (
 	"errors"
 	"fmt"
 	"io"
+	"net"
 	"net/http"
 	"reflect"
 	"runtime"
@@ -151,7 +152,7 @@ func (c *Conn) read(ctx context.Context) (MessageType, []byte, error) {
 		return 0, nil, ctx.Err()
 	case <-c.readSignal:
 	case <-c.closed:
-		return 0, nil, errClosed
+		return 0, nil, net.ErrClosed
 	}
 
 	c.readBufMu.Lock()
@@ -205,7 +206,7 @@ func (c *Conn) Write(ctx context.Context, typ MessageType, p []byte) error {
 
 func (c *Conn) write(ctx context.Context, typ MessageType, p []byte) error {
 	if c.isClosed() {
-		return errClosed
+		return net.ErrClosed
 	}
 	switch typ {
 	case MessageBinary:
@@ -243,7 +244,7 @@ func (c *Conn) exportedClose(code StatusCode, reason string) error {
 	defer c.closingMu.Unlock()
 
 	if c.isClosed() {
-		return errClosed
+		return net.ErrClosed
 	}
 
 	ce := fmt.Errorf("sent close: %w", CloseError{
@@ -321,7 +322,7 @@ func dial(ctx context.Context, url string, opts *DialOptions) (*Conn, *http.Resp
 			StatusCode: http.StatusSwitchingProtocols,
 		}, nil
 	case <-c.closed:
-		return nil, nil, errClosed
+		return nil, nil, net.ErrClosed
 	}
 }