export ErrConnectionClosed (#2152)

fasthttputil/pipeconns.go

@@ -121,7 +121,7 @@ func (c *pipeConn) Write(p []byte) (int, error) {
 	select {
 	case <-c.pc.stopCh:
 		releaseByteBuffer(b)
-		return 0, errConnectionClosed
+		return 0, ErrConnectionClosed
 	default:
 	}
 
@@ -135,7 +135,7 @@ func (c *pipeConn) Write(p []byte) (int, error) {
 			return 0, ErrTimeout
 		case <-c.pc.stopCh:
 			releaseByteBuffer(b)
-			return 0, errConnectionClosed
+			return 0, ErrConnectionClosed
 		}
 	}
 
@@ -218,10 +218,10 @@ func (c *pipeConn) readNextByteBuffer(mayBlock bool) error {
 	return nil
 }
 
-var (
-	errWouldBlock       = errors.New("would block")
-	errConnectionClosed = errors.New("connection closed")
-)
+var errWouldBlock = errors.New("would block")
+
+// ErrConnectionClosed indicates that the underlying connection is closed. It could mean that the client has disconnected.
+var ErrConnectionClosed = errors.New("connection closed")
 
 type timeoutError struct{}
 

fasthttputil/pipeconns_test.go

@@ -162,7 +162,7 @@ func testPipeConnsCloseWhileReadWrite(t *testing.T) {
 	go func() {
 		var err error
 		if _, err = io.Copy(io.Discard, c1); err != nil {
-			if err != errConnectionClosed {
+			if err != ErrConnectionClosed {
 				err = fmt.Errorf("unexpected error: %w", err)
 			} else {
 				err = nil
@@ -176,7 +176,7 @@ func testPipeConnsCloseWhileReadWrite(t *testing.T) {
 		var err error
 		for {
 			if _, err = c2.Write([]byte("foobar")); err != nil {
-				if err != errConnectionClosed {
+				if err != ErrConnectionClosed {
 					err = fmt.Errorf("unexpected error: %w", err)
 				} else {
 					err = nil