re-implement TestReadPacketWrongSequenceID

Author: shogo82148

connection.go

@@ -154,7 +154,7 @@ func (mc *mysqlConn) Close() error {
 func (mc *mysqlConn) closeContext(ctx context.Context) (err error) {
 	// Makes Close idempotent
 	if !mc.closed.Load() {
-		err = mc.writeCommandPacket(context.Background(), comQuit)
+		err = mc.writeCommandPacket(ctx, comQuit)
 	}
 
 	mc.cleanup()

packets.go

@@ -43,9 +43,9 @@ func (mc *mysqlConn) readPacket(ctx context.Context) ([]byte, error) {
 		pktLen := int(uint32(mc.data[0]) | uint32(mc.data[1])<<8 | uint32(mc.data[2])<<16)
 
 		// check packet sync [8 bit]
-		if mc.data[3] != mc.sequence {
+		if seq := mc.data[3]; seq != mc.sequence {
 			mc.closeContext(ctx)
-			if mc.data[3] > mc.sequence {
+			if seq > mc.sequence {
 				return nil, ErrPktSyncMul
 			}
 			return nil, ErrPktSync

packets_test.go

@@ -10,6 +10,7 @@ package mysql
 
 import (
 	"context"
+	"io"
 	"net"
 	"testing"
 )
@@ -52,37 +53,43 @@ func TestReadPacketSingleByte(t *testing.T) {
 	}
 }
 
-// func TestReadPacketWrongSequenceID(t *testing.T) {
-// 	for _, testCase := range []struct {
-// 		ClientSequenceID byte
-// 		ServerSequenceID byte
-// 		ExpectedErr      error
-// 	}{
-// 		{
-// 			ClientSequenceID: 1,
-// 			ServerSequenceID: 0,
-// 			ExpectedErr:      ErrPktSync,
-// 		},
-// 		{
-// 			ClientSequenceID: 0,
-// 			ServerSequenceID: 0x42,
-// 			ExpectedErr:      ErrPktSyncMul,
-// 		},
-// 	} {
-// 		conn, mc := newRWMockConn(testCase.ClientSequenceID)
-
-// 		conn.data = []byte{0x01, 0x00, 0x00, testCase.ServerSequenceID, 0xff}
-// 		_, err := mc.readPacket()
-// 		if err != testCase.ExpectedErr {
-// 			t.Errorf("expected %v, got %v", testCase.ExpectedErr, err)
-// 		}
-
-// 		// connection should not be returned to the pool in this state
-// 		if mc.IsValid() {
-// 			t.Errorf("expected IsValid() to be false")
-// 		}
-// 	}
-// }
+func TestReadPacketWrongSequenceID(t *testing.T) {
+	for _, testCase := range []struct {
+		ClientSequenceID byte
+		ServerSequenceID byte
+		ExpectedErr      error
+	}{
+		{
+			ClientSequenceID: 1,
+			ServerSequenceID: 0,
+			ExpectedErr:      ErrPktSync,
+		},
+		{
+			ClientSequenceID: 0,
+			ServerSequenceID: 0x42,
+			ExpectedErr:      ErrPktSyncMul,
+		},
+	} {
+		testCase := testCase
+
+		conn, mc := newRWMockConn(t, testCase.ClientSequenceID)
+		go func() {
+			io.Copy(io.Discard, conn)
+		}()
+		go func() {
+			conn.Write([]byte{0x01, 0x00, 0x00, testCase.ServerSequenceID, 0xff})
+		}()
+		_, err := mc.readPacket(context.Background())
+		if err != testCase.ExpectedErr {
+			t.Errorf(`expected "%v", got "%v"`, testCase.ExpectedErr, err)
+		}
+
+		// connection should not be returned to the pool in this state
+		if mc.IsValid() {
+			t.Errorf("expected IsValid() to be false")
+		}
+	}
+}
 
 // func TestReadPacketSplit(t *testing.T) {
 // 	conn := new(mockConn)