test: 补齐短时间可测验收并修复建群下行卡住

test/accept/mqtt.go

@@ -33,15 +33,27 @@ type AppResp struct {
 	Raw   map[string]any
 }
 
+// MQTTLoginOpts 控制握手参数。
+type MQTTLoginOpts struct {
+	// MaxReceiveBytes 非 nil 时写入 hello.max_receive_bytes。
+	MaxReceiveBytes *int
+}
+
 // MQTTLogin 用密码连上 /mqtt、订阅 down、完成 hello。
 func MQTTLogin(t *testing.T, httpBase, endpointID, password string) *MQTTSession {
 	t.Helper()
-	mc, err := harness.DialMQTTWebSocket(httpBase, 10*time.Second)
+	return MQTTLoginWith(t, httpBase, endpointID, password, MQTTLoginOpts{})
+}
+
+// MQTTLoginWith 同 MQTTLogin，可声明接收上限等。
+func MQTTLoginWith(t *testing.T, httpBase, endpointID, password string, opts MQTTLoginOpts) *MQTTSession {
+	t.Helper()
+	mc, err := harness.DialMQTTWebSocket(httpBase, 15*time.Second)
 	if err != nil {
 		t.Fatalf("dial mqtt: %v", err)
 	}
 	s := &MQTTSession{t: t, mc: mc, EndpointID: endpointID, pktID: 10, done: make(chan struct{})}
-	s.connectSubscribeHello(password)
+	s.connectSubscribeHello(password, opts)
 	go s.readLoop()
 	return s
 }
@@ -70,7 +82,7 @@ func (s *MQTTSession) nextPkt() uint16 {
 	return s.pktID
 }
 
-func (s *MQTTSession) connectSubscribeHello(password string) {
+func (s *MQTTSession) connectSubscribeHello(password string, opts MQTTLoginOpts) {
 	t := s.t
 	pk := packets.Packet{
 		FixedHeader:     packets.FixedHeader{Type: packets.Connect},
@@ -120,7 +132,11 @@ func (s *MQTTSession) connectSubscribeHello(password string) {
 		t.Fatal(err)
 	}
 
-	hello, _ := protocol.Marshal(protocol.Hello{V: protocol.Version, Type: protocol.TypeHello, RID: "h0"})
+	helloFrame := protocol.Hello{V: protocol.Version, Type: protocol.TypeHello, RID: "h0"}
+	if opts.MaxReceiveBytes != nil {
+		helloFrame.MaxReceiveBytes = opts.MaxReceiveBytes
+	}
+	hello, _ := protocol.Marshal(helloFrame)
 	s.publishRaw(hello)
 	deadline := time.Now().Add(10 * time.Second)
 	for time.Now().Before(deadline) {