1 files changed, 137 insertions, 0 deletions
diff --git a/chromium/third_party/nearby/src/connections/implementation/mediums/lost_entity_tracker_test.cc b/chromium/third_party/nearby/src/connections/implementation/mediums/lost_entity_tracker_test.cc
new file mode 100644
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+++ b/chromium/third_party/nearby/src/connections/implementation/mediums/lost_entity_tracker_test.cc
@@ -0,0 +1,137 @@
+// Copyright 2020 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "connections/implementation/mediums/lost_entity_tracker.h"
+
+#include "gtest/gtest.h"
+
+namespace location {
+namespace nearby {
+namespace connections {
+namespace mediums {
+namespace {
+
+struct TestEntity {
+  int id;
+
+  template <typename H>
+  friend H AbslHashValue(H h, const TestEntity& test_entity) {
+    return H::combine(std::move(h), test_entity.id);
+  }
+
+  bool operator==(const TestEntity& other) const { return id == other.id; }
+  bool operator<(const TestEntity& other) const { return id < other.id; }
+};
+
+TEST(LostEntityTrackerTest, NoEntitiesLost) {
+  LostEntityTracker<TestEntity> lost_entity_tracker;
+  TestEntity entity_1{1};
+  TestEntity entity_2{2};
+  TestEntity entity_3{3};
+
+  // Discover some entities.
+  lost_entity_tracker.RecordFoundEntity(entity_1);
+  lost_entity_tracker.RecordFoundEntity(entity_2);
+  lost_entity_tracker.RecordFoundEntity(entity_3);
+
+  // Make sure none are lost on the first round.
+  ASSERT_TRUE(lost_entity_tracker.ComputeLostEntities().empty());
+
+  // Rediscover the same entities.
+  lost_entity_tracker.RecordFoundEntity(entity_1);
+  lost_entity_tracker.RecordFoundEntity(entity_2);
+  lost_entity_tracker.RecordFoundEntity(entity_3);
+
+  // Make sure we still didn't lose any entities.
+  EXPECT_TRUE(lost_entity_tracker.ComputeLostEntities().empty());
+}
+
+TEST(LostEntityTrackerTest, AllEntitiesLost) {
+  LostEntityTracker<TestEntity> lost_entity_tracker;
+  TestEntity entity_1{1};
+  TestEntity entity_2{2};
+  TestEntity entity_3{3};
+
+  // Discover some entities.
+  lost_entity_tracker.RecordFoundEntity(entity_1);
+  lost_entity_tracker.RecordFoundEntity(entity_2);
+  lost_entity_tracker.RecordFoundEntity(entity_3);
+
+  // Make sure none are lost on the first round.
+  EXPECT_TRUE(lost_entity_tracker.ComputeLostEntities().empty());
+
+  // Go through a round without rediscovering any entities.
+  typename LostEntityTracker<TestEntity>::EntitySet lost_entities =
+      lost_entity_tracker.ComputeLostEntities();
+  EXPECT_TRUE(lost_entities.find(entity_1) != lost_entities.end());
+  EXPECT_TRUE(lost_entities.find(entity_2) != lost_entities.end());
+  EXPECT_TRUE(lost_entities.find(entity_3) != lost_entities.end());
+}
+
+TEST(LostEntityTrackerTest, SomeEntitiesLost) {
+  LostEntityTracker<TestEntity> lost_entity_tracker;
+  TestEntity entity_1{1};
+  TestEntity entity_2{2};
+  TestEntity entity_3{3};
+
+  // Discover some entities.
+  lost_entity_tracker.RecordFoundEntity(entity_1);
+  lost_entity_tracker.RecordFoundEntity(entity_2);
+
+  // Make sure none are lost on the first round.
+  EXPECT_TRUE(lost_entity_tracker.ComputeLostEntities().empty());
+
+  // Go through the next round only rediscovering one of our entities and
+  // discovering an additional entity as well. Then, verify that only one entity
+  // was lost after the check.
+  lost_entity_tracker.RecordFoundEntity(entity_1);
+  lost_entity_tracker.RecordFoundEntity(entity_3);
+  typename LostEntityTracker<TestEntity>::EntitySet lost_entities =
+      lost_entity_tracker.ComputeLostEntities();
+  EXPECT_TRUE(lost_entities.find(entity_1) == lost_entities.end());
+  EXPECT_TRUE(lost_entities.find(entity_2) != lost_entities.end());
+  EXPECT_TRUE(lost_entities.find(entity_3) == lost_entities.end());
+}
+
+TEST(LostEntityTrackerTest, SameEntityMultipleCopies) {
+  LostEntityTracker<TestEntity> lost_entity_tracker;
+  TestEntity entity_1{1};
+  TestEntity entity_1_copy{1};
+
+  // Discover an entity.
+  lost_entity_tracker.RecordFoundEntity(entity_1);
+
+  // Make sure none are lost on the first round.
+  EXPECT_TRUE(lost_entity_tracker.ComputeLostEntities().empty());
+
+  // Rediscover the same entity, but through a copy of it.
+  lost_entity_tracker.RecordFoundEntity(entity_1_copy);
+
+  // Make sure none are lost on the second round.
+  EXPECT_TRUE(lost_entity_tracker.ComputeLostEntities().empty());
+
+  // Go through a round without rediscovering any entities and verify that we
+  // lost an entity equivalent to both copies of it.
+  typename LostEntityTracker<TestEntity>::EntitySet lost_entities =
+      lost_entity_tracker.ComputeLostEntities();
+  EXPECT_EQ(lost_entities.size(), 1);
+  EXPECT_TRUE(lost_entities.find(entity_1) != lost_entities.end());
+  EXPECT_TRUE(lost_entities.find(entity_1_copy) != lost_entities.end());
+}
+
+}  // namespace
+}  // namespace mediums
+}  // namespace connections
+}  // namespace nearby
+}  // namespace location