fix: reject CMPP daily limit synchronously

gateway/internal/inbound/server_test.go

@@ -12,6 +12,7 @@ import (
 	"reflect"
 	"strings"
 	"sync"
+	"sync/atomic"
 	"testing"
 	"time"
 
@@ -310,6 +311,61 @@ func TestSubmitResponsePrecedesQueuedFailureReceipt(t *testing.T) {
 	}
 }
 
+func TestDailyLimitRejectsSubmitSynchronouslyWithoutPendingReceipt(t *testing.T) {
+	resetDownstreamRegistry()
+	defer resetDownstreamRegistry()
+	account := "100001"
+	password := "secret-hash"
+	var pendingCalls atomic.Int32
+
+	api := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		switch r.URL.Path {
+		case "/api/gateway/events/inbound/authenticate":
+			_ = json.NewEncoder(w).Encode(authResponse{PasswordCipher: password, Account: account, EnterpriseCode: account})
+		case "/api/gateway/events/inbound/submit":
+			_ = json.NewEncoder(w).Encode(submitResponse{Accepted: false, Result: 8, MessageID: "MSG-LIMIT"})
+		case "/api/gateway/events/downstream/pending":
+			pendingCalls.Add(1)
+			_ = json.NewEncoder(w).Encode([]pendingDelivery{})
+		case "/api/gateway/events/inbound/connection":
+			w.WriteHeader(http.StatusOK)
+		default:
+			t.Fatalf("unexpected api path: %s", r.URL.Path)
+		}
+	}))
+	defer api.Close()
+
+	addr := reserveTCPAddr(t)
+	go func() { _ = (Server{Addr: addr, APIBaseURL: api.URL + "/api"}).ListenAndServe() }()
+	time.Sleep(300 * time.Millisecond)
+
+	client := cmpp.NewClient(cmpp.V20)
+	defer client.Disconnect()
+	if err := client.Connect(addr, account, password, 2*time.Second); err != nil {
+		t.Fatalf("connect CMPP2 inbound: %v", err)
+	}
+	time.Sleep(100 * time.Millisecond)
+	pendingCallsAfterBind := pendingCalls.Load()
+	content, _ := cmpputils.Utf8ToUcs2("日限额拒绝")
+	if _, err := client.SendReqPkt(&cmpp.Cmpp2SubmitReqPkt{
+		PkTotal: 1, PkNumber: 1, RegisteredDelivery: 1, MsgLevel: 1,
+		ServiceId: "cmpp", FeeUserType: 2, FeeTerminalId: "13500002696",
+		MsgFmt: 8, MsgSrc: account, FeeType: "02", FeeCode: "0", SrcId: "10690000",
+		DestUsrTl: 1, DestTerminalId: []string{"13500002696"}, MsgLength: uint8(len(content)), MsgContent: content,
+	}); err != nil {
+		t.Fatalf("send submit: %v", err)
+	}
+
+	rsp := recvSubmitRsp20(t, client)
+	if rsp.Result != 8 || rsp.MsgId != 0 {
+		t.Fatalf("expected synchronous daily-limit result=8 without Msg_Id, got %+v", rsp)
+	}
+	time.Sleep(100 * time.Millisecond)
+	if pendingCalls.Load() != pendingCallsAfterBind {
+		t.Fatalf("daily-limit rejection must not add downstream receipt polling, before=%d after=%d", pendingCallsAfterBind, pendingCalls.Load())
+	}
+}
+
 func TestReceiptWithoutOriginalSequenceIsUnrecoverable(t *testing.T) {
 	resetDownstreamRegistry()
 	defer resetDownstreamRegistry()