[KQP] empty plan test plan crash (#17727)

Author: pashandor789

ydb/core/kqp/ut/common/kqp_ut_common.cpp

@@ -1543,6 +1543,10 @@ void WaitForCompaction(Tests::TServer* server, const TString& path, bool compact
 }
 
 NJson::TJsonValue SimplifyPlan(NJson::TJsonValue& opt, const TGetPlanParams& params) {
+    Cout << opt.GetStringRobust() << Endl;
+    if (!opt.IsMap()) {
+        return {};
+    }
     const auto& [_, nodeType] = *opt.GetMapSafe().find("Node Type");
     bool isShuffle = nodeType.GetStringSafe().find("HashShuffle") != TString::npos;
 
@@ -1574,8 +1578,12 @@ NJson::TJsonValue SimplifyPlan(NJson::TJsonValue& opt, const TGetPlanParams& par
         }
     }
 
-    auto firstPlan = opt.GetMapSafe().at("Plans").GetArraySafe()[0];
-    return SimplifyPlan(firstPlan, params);
+    if (opt.IsMap() && opt.GetMapSafe().contains("Plans")) {
+        auto firstPlan = opt.GetMapSafe().at("Plans").GetArraySafe()[0];
+        return SimplifyPlan(firstPlan, params);
+    }
+
+    return {};
 }
 
 bool JoinOrderAndAlgosMatch(const NJson::TJsonValue& opt, const NJson::TJsonValue& ref) {
@@ -1653,6 +1661,10 @@ NJson::TJsonValue GetDetailedJoinOrder(const TString& deserializedPlan, const TG
 }
 
 NJson::TJsonValue GetJoinOrderImpl(const NJson::TJsonValue& opt) {
+    if (!opt.IsMap()) {
+        return {};
+    }
+
     if (!opt.GetMapSafe().contains("Plans")) {
         auto op = opt.GetMapSafe().at("Operators").GetArraySafe()[0];
         return op.GetMapSafe().at("Table").GetStringSafe();
@@ -1676,6 +1688,10 @@ NJson::TJsonValue GetJoinOrder(const TString& deserializedPlan) {
 }
 
 NJson::TJsonValue GetJoinOrderFromDetailedJoinOrderImpl(const NJson::TJsonValue& opt) {
+    if (!opt.IsMap()) {
+        return {};
+    }
+    
     if (!opt.GetMapSafe().contains("table")) {
         NJson::TJsonValue res;
         auto args = opt.GetMapSafe().at("args").GetArraySafe();