1 files changed, 133 insertions, 0 deletions
diff --git a/src/jaegertracing/opentelemetry-cpp/sdk/test/_metrics/gauge_aggregator_test.cc b/src/jaegertracing/opentelemetry-cpp/sdk/test/_metrics/gauge_aggregator_test.cc
new file mode 100644
index 000000000..9565e0629
--- /dev/null
+++ b/src/jaegertracing/opentelemetry-cpp/sdk/test/_metrics/gauge_aggregator_test.cc
@@ -0,0 +1,133 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+#ifdef ENABLE_METRICS_PREVIEW
+#  include <gtest/gtest.h>
+#  include <thread>
+
+#  include "opentelemetry/sdk/_metrics/aggregator/gauge_aggregator.h"
+
+using namespace opentelemetry::sdk::metrics;
+namespace metrics_api = opentelemetry::metrics;
+
+TEST(GaugeAggregator, Update)
+{
+  // This tests that the aggregator updates the maintained value correctly
+  // after a call to the update() function.
+  auto agg = new GaugeAggregator<int>(metrics_api::InstrumentKind::Counter);
+
+  // Verify default value
+  ASSERT_EQ(agg->get_values()[0], 0);
+
+  // Verify that the value updates correctly
+  agg->update(1);
+  ASSERT_EQ(agg->get_values()[0], 1);
+
+  // Verify that the value continually updates correctly
+  for (int i = 0; i < 10; ++i)
+  {
+    agg->update(i);
+  }
+  ASSERT_EQ(agg->get_values()[0], 9);
+  delete agg;
+}
+
+TEST(GaugeAggregator, Checkpoint)
+{
+  // This tests that the aggregator correctly updates the
+  // checkpoint_ value after a call to update() followed
+  // by a call to checkpoint().
+  GaugeAggregator<int> agg(metrics_api::InstrumentKind::Counter);
+
+  // Verify default checkpoint, before updates
+  ASSERT_EQ(agg.get_checkpoint()[0], 0);
+
+  agg.update(10);
+  agg.checkpoint();
+
+  // Verify that the new checkpoint contains the update value
+  ASSERT_EQ(agg.get_checkpoint()[0], 10);
+}
+
+TEST(GaugeAggregator, Merge)
+{
+  // This tests that the values_ vector is updated correctly after
+  // two aggregators are merged together.
+  GaugeAggregator<int> agg1(metrics_api::InstrumentKind::Counter);
+  GaugeAggregator<int> agg2(metrics_api::InstrumentKind::Counter);
+
+  agg1.update(1);
+  agg2.update(2);
+
+  agg1.merge(agg2);
+
+  // Verify that the aggregators merged and the value was updated correctly
+  ASSERT_EQ(agg1.get_values()[0], 2);
+}
+
+TEST(GaugeAggregator, BadMerge)
+{
+  // This verifies that we encounter and error when we try to merge
+  // two aggregators of different numeric types together.
+  GaugeAggregator<int> agg1(metrics_api::InstrumentKind::Counter);
+  GaugeAggregator<int> agg2(metrics_api::InstrumentKind::ValueRecorder);
+
+  agg1.update(1);
+  agg2.update(2);
+  agg1.merge(agg2);
+
+  // Verify that the aggregators did NOT merge
+  std::vector<int> correct{1};
+  ASSERT_EQ(agg1.get_values(), correct);
+}
+
+TEST(GaugeAggregator, Types)
+{
+  // This test verifies that we do not encounter any errors when
+  // using various numeric types.
+  GaugeAggregator<int> agg_int(metrics_api::InstrumentKind::Counter);
+  GaugeAggregator<long> agg_long(metrics_api::InstrumentKind::Counter);
+  GaugeAggregator<float> agg_float(metrics_api::InstrumentKind::Counter);
+  GaugeAggregator<double> agg_double(metrics_api::InstrumentKind::Counter);
+
+  for (int i = 1; i <= 10; ++i)
+  {
+    agg_int.update(i);
+    agg_long.update(i);
+  }
+
+  for (float i = 1.0; i <= 10.0; i += 1)
+  {
+    agg_float.update(i);
+    agg_double.update(i);
+  }
+
+  ASSERT_EQ(agg_int.get_values()[0], 10);
+  ASSERT_EQ(agg_long.get_values()[0], 10);
+  ASSERT_EQ(agg_float.get_values()[0], 10.0);
+  ASSERT_EQ(agg_double.get_values()[0], 10.0);
+}
+
+static void callback(GaugeAggregator<int> &agg)
+{
+  for (int i = 1; i <= 10000; ++i)
+  {
+    agg.update(i);
+  }
+}
+
+TEST(GaugeAggregator, Concurrency)
+{
+  // This test checks that the aggregator updates appropriately
+  // when called in a multi-threaded context.
+  GaugeAggregator<int> agg(metrics_api::InstrumentKind::Counter);
+
+  std::thread first(&callback, std::ref(agg));
+  std::thread second(&callback, std::ref(agg));
+
+  first.join();
+  second.join();
+
+  ASSERT_EQ(agg.get_values()[0], 10000);
+}
+#endif