From 741ab5b28f26a62e77af295eb94c1c556e0673ac Mon Sep 17 00:00:00 2001
From: Arkadiusz Szczepkowicz <arek.szczepkowicz@ng-analytics.com>
Date: Tue, 13 Jun 2023 17:14:28 +0200
Subject: [PATCH] #2162: Fix vt aborting when lb file dont have metadata

---
 .../vrt/collection/balance/lb_data_holder.cc  | 64 ++++++++++---------
 tests/unit/collection/test_lb_data_holder.cc  | 27 ++++++++
 2 files changed, 60 insertions(+), 31 deletions(-)

diff --git a/src/vt/vrt/collection/balance/lb_data_holder.cc b/src/vt/vrt/collection/balance/lb_data_holder.cc
index d591773d71..c2da1c2bf5 100644
--- a/src/vt/vrt/collection/balance/lb_data_holder.cc
+++ b/src/vt/vrt/collection/balance/lb_data_holder.cc
@@ -374,41 +374,43 @@ LBDataHolder::LBDataHolder(nlohmann::json const& j)
 }
 
 void LBDataHolder::readMetadata(nlohmann::json const& j) {
-  auto metadata = j["metadata"];
-  if (metadata.find("phases") != metadata.end()) {
-    auto phases = metadata["phases"];
-    // load count
-    vtAssertExpr(phases["count"].is_number());
-    count_ = phases["count"];
-    // load all skipped phases
-    auto sl = phases["skipped"]["list"];
-    if(sl.is_array()) {
-      for(PhaseType skipped : sl) {
-        skipped_phases_.insert(skipped);
+  if (j.find("metadata") != j.end()) {
+    auto metadata = j["metadata"];
+    if (metadata.find("phases") != metadata.end()) {
+      auto phases = metadata["phases"];
+      // load count
+      vtAssertExpr(phases["count"].is_number());
+      count_ = phases["count"];
+      // load all skipped phases
+      auto sl = phases["skipped"]["list"];
+      if(sl.is_array()) {
+        for(PhaseType skipped : sl) {
+          skipped_phases_.insert(skipped);
+        }
       }
-    }
-    auto sr = phases["skipped"]["range"];
-    if(sr.is_array()) {
-      for(auto const& pair : sr) {
-        vtAssertExpr(pair.is_array());
-        for(PhaseType i = pair[0]; i <= pair[1]; i++){
-          skipped_phases_.insert(i);
+      auto sr = phases["skipped"]["range"];
+      if(sr.is_array()) {
+        for(auto const& pair : sr) {
+          vtAssertExpr(pair.is_array());
+          for(PhaseType i = pair[0]; i <= pair[1]; i++){
+            skipped_phases_.insert(i);
+          }
         }
       }
-    }
-    // load all identical phases
-    auto il = phases["identical_to_previous"]["list"];
-    if(il.is_array()) {
-      for(PhaseType identical : il) {
-        identical_phases_.insert(identical);
+      // load all identical phases
+      auto il = phases["identical_to_previous"]["list"];
+      if(il.is_array()) {
+        for(PhaseType identical : il) {
+          identical_phases_.insert(identical);
+        }
       }
-    }
-    auto ir = phases["identical_to_previous"]["range"];
-    if(ir.is_array()) {
-      for(auto const& pair : ir) {
-        vtAssertExpr(pair.is_array());
-        for(PhaseType i = pair[0]; i <= pair[1]; i++){
-          identical_phases_.insert(i);
+      auto ir = phases["identical_to_previous"]["range"];
+      if(ir.is_array()) {
+        for(auto const& pair : ir) {
+          vtAssertExpr(pair.is_array());
+          for(PhaseType i = pair[0]; i <= pair[1]; i++){
+            identical_phases_.insert(i);
+          }
         }
       }
     }
diff --git a/tests/unit/collection/test_lb_data_holder.cc b/tests/unit/collection/test_lb_data_holder.cc
index 9733baa84b..9b2bec90c5 100644
--- a/tests/unit/collection/test_lb_data_holder.cc
+++ b/tests/unit/collection/test_lb_data_holder.cc
@@ -90,6 +90,33 @@ void addPhasesDataToJson(nlohmann::json& json, PhaseType amountOfPhasesToAdd, st
   json["phases"] = phases;
 }
 
+TEST_F(TestOptionalPhasesMetadata, test_no_metadata) {
+  using LBDataHolder = vt::vrt::collection::balance::LBDataHolder;
+
+  nlohmann::json json;
+  addPhasesDataToJson(json, num_phases, {});
+
+  LBDataHolder testObj(json);
+  EXPECT_EQ(testObj.count_, num_phases);
+  std::set<PhaseType> expectedSkipped = {};
+  EXPECT_EQ(testObj.skipped_phases_, expectedSkipped);
+  std::set<PhaseType> expectedIdentical = {};
+  EXPECT_EQ(testObj.identical_phases_, expectedIdentical);
+
+  auto outJsonPtr = testObj.metadataToJson();
+  ASSERT_TRUE(outJsonPtr != nullptr);
+
+  EXPECT_EQ((*outJsonPtr)["count"], num_phases);
+  std::vector<PhaseType> expectedSkippedList = {};
+  EXPECT_EQ((*outJsonPtr)["skipped"]["list"], expectedSkippedList);
+  std::vector<std::pair<PhaseType, PhaseType>> expectedSkippedRanges = {};
+  EXPECT_EQ((*outJsonPtr)["skipped"]["range"], expectedSkippedRanges);
+  std::vector<PhaseType> expectedIdenticalList = {};
+  EXPECT_EQ((*outJsonPtr)["identical_to_previous"]["list"], expectedIdenticalList);
+  std::vector<std::pair<PhaseType, PhaseType>> expectedIdenticalRanges = {};
+  EXPECT_EQ((*outJsonPtr)["identical_to_previous"]["range"], expectedIdenticalRanges);
+}
+
 TEST_F(TestOptionalPhasesMetadata, test_no_lb_phases_metadata) {
   using LBDataHolder = vt::vrt::collection::balance::LBDataHolder;