fix: reject unrouted messages without seq

server/db/mysql/group_schema_test.go

@@ -7,6 +7,7 @@ import (
 	"strings"
 	"testing"
 
+	"github.com/tinode/chat/server/store"
 	types "github.com/tinode/chat/server/store/types"
 )
 
@@ -75,6 +76,21 @@ func TestGroupMessageShardTableRejectsUnsafeMonth(t *testing.T) {
 	}
 }
 
+func TestGroupMessageShardTablesForSeqFiltersRoutes(t *testing.T) {
+	routes := []store.GroupMessageShardRoute{
+		{Month: "202608", MinSeq: 1, MaxSeq: 20},
+		{Month: "202609", MinSeq: 21, MaxSeq: 100},
+		{Month: "202613", MinSeq: 1, MaxSeq: 1000},
+	}
+	tables := groupMessageShardTablesForSeq(7, routes, 23)
+	if len(tables) != 1 || tables[0] != "im_007_group_messages_202609" {
+		t.Fatalf("unexpected shard tables for seq: %#v", tables)
+	}
+	if tables = groupMessageShardTablesForSeq(7, routes, 101); len(tables) != 0 {
+		t.Fatalf("unexpected shard tables for uncovered seq: %#v", tables)
+	}
+}
+
 func TestTenantPartitionTableNames(t *testing.T) {
 	tests := []struct {
 		tenantID types.TenantID