From eb8d352e3efdd3e95e1e0b6543b8140e9203e58a Mon Sep 17 00:00:00 2001
From: gabrielcorado <gabrielcorado@mail.com>
Date: Thu, 10 Dec 2020 10:39:50 -0300
Subject: [PATCH 1/2] refactor(acceptor): check if the header sizer is empty

---
 acceptor/tcp_acceptor.go      |  4 ++++
 acceptor/tcp_acceptor_test.go | 23 +++++++++++++++++++++++
 constants/errors.go           |  1 +
 3 files changed, 28 insertions(+)

diff --git a/acceptor/tcp_acceptor.go b/acceptor/tcp_acceptor.go
index 055efaf0..dadfeaf2 100644
--- a/acceptor/tcp_acceptor.go
+++ b/acceptor/tcp_acceptor.go
@@ -51,6 +51,10 @@ func (t *tcpPlayerConn) GetNextMessage() (b []byte, err error) {
 	if err != nil {
 		return nil, err
 	}
+	// if the header has no data, we can consider it as a closed connection
+	if len(header) == 0 {
+		return nil, constants.ErrConnectionClosed
+	}
 	msgSize, _, err := codec.ParseHeader(header)
 	if err != nil {
 		return nil, err
diff --git a/acceptor/tcp_acceptor_test.go b/acceptor/tcp_acceptor_test.go
index ff050d54..ca608aa7 100644
--- a/acceptor/tcp_acceptor_test.go
+++ b/acceptor/tcp_acceptor_test.go
@@ -242,7 +242,30 @@ func TestGetNextMessageEOF(t *testing.T) {
 
 	_, err = playerConn.GetNextMessage()
 	assert.EqualError(t, err, constants.ErrReceivedMsgSmallerThanExpected.Error())
+}
 
+func TestGetNextMessageEmptyEOF(t *testing.T) {
+	a := NewTCPAcceptor("0.0.0.0:0")
+	go a.ListenAndServe()
+	defer a.Stop()
+	c := a.GetConnChan()
+	// should be able to connect within 100 milliseconds
+	var conn net.Conn
+	var err error
+	helpers.ShouldEventuallyReturn(t, func() error {
+		conn, err = net.Dial("tcp", a.GetAddr())
+		return err
+	}, nil, 10*time.Millisecond, 100*time.Millisecond)
+
+	playerConn := helpers.ShouldEventuallyReceive(t, c, 100*time.Millisecond).(PlayerConn)
+
+	go func() {
+		time.Sleep(100 * time.Millisecond)
+		conn.Close()
+	}()
+
+	_, err = playerConn.GetNextMessage()
+	assert.EqualError(t, err, constants.ErrConnectionClosed.Error())
 }
 
 func TestGetNextMessageInParts(t *testing.T) {
diff --git a/constants/errors.go b/constants/errors.go
index 9e88fa74..b254cac0 100644
--- a/constants/errors.go
+++ b/constants/errors.go
@@ -84,4 +84,5 @@ var (
 	ErrRateLimitExceeded              = errors.New("rate limit exceeded")
 	ErrReceivedMsgSmallerThanExpected = errors.New("received less data than expected, EOF?")
 	ErrReceivedMsgBiggerThanExpected  = errors.New("received more data than expected")
+	ErrConnectionClosed               = errors.New("client connection closed")
 )

From fb0f0d0206ce6f91a66b1e68e646c6ad13d7467e Mon Sep 17 00:00:00 2001
From: gabrielcorado <gabrielcorado@mail.com>
Date: Thu, 10 Dec 2020 10:40:38 -0300
Subject: [PATCH 2/2] refactor(service): do not log message as an error what it
 is only closed

---
 service/handler.go | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/service/handler.go b/service/handler.go
index 5026bebe..0cba8932 100644
--- a/service/handler.go
+++ b/service/handler.go
@@ -183,7 +183,10 @@ func (h *HandlerService) Handle(conn acceptor.PlayerConn) {
 		msg, err := conn.GetNextMessage()
 
 		if err != nil {
-			logger.Log.Errorf("Error reading next available message: %s", err.Error())
+			if err != constants.ErrConnectionClosed {
+				logger.Log.Errorf("Error reading next available message: %s", err.Error())
+			}
+
 			return
 		}