test: add first-version coverage

gateway/internal/tracker/tracker_test.go

@@ -1,6 +1,10 @@
 package tracker
 
-import "testing"
+import (
+	"fmt"
+	"sync"
+	"testing"
+)
 
 func TestTrackerMapsMessageSequenceAndGatewayIDs(t *testing.T) {
 	tr := New()
@@ -34,3 +38,51 @@ func TestTrackerRejectsUnknownSubmitResp(t *testing.T) {
 		t.Fatal("expected missing mapping error")
 	}
 }
+
+func TestTrackerKeepsConcurrentSequenceAndGatewayMappingsSeparate(t *testing.T) {
+	tr := New()
+	var wg sync.WaitGroup
+
+	for i := 0; i < 100; i++ {
+		wg.Add(1)
+		go func(i int) {
+			defer wg.Done()
+			messageID := fmt.Sprintf("msg-%03d", i)
+			gatewayID := fmt.Sprintf("gw-%03d", i)
+			sequenceID := uint32(2000 + i)
+
+			tr.TrackSubmit(messageID, sequenceID)
+			mapping, err := tr.TrackSubmitResp(sequenceID, gatewayID)
+			if err != nil {
+				t.Errorf("track submit resp for %s: %v", messageID, err)
+				return
+			}
+			if mapping.MessageID != messageID || mapping.SequenceID != sequenceID || mapping.GatewayMessageID != gatewayID {
+				t.Errorf("unexpected mapping: %+v", mapping)
+			}
+		}(i)
+	}
+	wg.Wait()
+
+	for i := 0; i < 100; i++ {
+		messageID := fmt.Sprintf("msg-%03d", i)
+		gatewayID := fmt.Sprintf("gw-%03d", i)
+		sequenceID := uint32(2000 + i)
+
+		byGateway, err := tr.ByGatewayMessageID(gatewayID)
+		if err != nil {
+			t.Fatalf("lookup gateway %s: %v", gatewayID, err)
+		}
+		if byGateway.MessageID != messageID || byGateway.SequenceID != sequenceID {
+			t.Fatalf("gateway lookup crossed mappings: %+v", byGateway)
+		}
+
+		byMessage, err := tr.ByMessageID(messageID)
+		if err != nil {
+			t.Fatalf("lookup message %s: %v", messageID, err)
+		}
+		if byMessage.GatewayMessageID != gatewayID || byMessage.SequenceID != sequenceID {
+			t.Fatalf("message lookup crossed mappings: %+v", byMessage)
+		}
+	}
+}