1 files changed, 92 insertions, 0 deletions
diff --git a/kamon-core/src/test/scala/kamon/metric/TraceMetricsSpec.scala b/kamon-core/src/test/scala/kamon/metric/TraceMetricsSpec.scala
new file mode 100644
index 00000000..dab9b52a
--- /dev/null
+++ b/kamon-core/src/test/scala/kamon/metric/TraceMetricsSpec.scala
@@ -0,0 +1,92 @@
+package kamon.metric
+
+import akka.actor.ActorSystem
+import akka.testkit.{ ImplicitSender, TestKitBase }
+import com.typesafe.config.ConfigFactory
+import kamon.Kamon
+import kamon.metric.TraceMetrics.TraceMetricsSnapshot
+import kamon.trace.TraceContext.SegmentIdentity
+import kamon.trace.TraceRecorder
+import org.scalatest.{ Matchers, WordSpecLike }
+
+class TraceMetricsSpec extends TestKitBase with WordSpecLike with Matchers with ImplicitSender {
+  implicit lazy val system: ActorSystem = ActorSystem("trace-metrics-spec", ConfigFactory.parseString(
+    """
+      |kamon.metrics {
+      |  tick-interval = 1 hour
+      |  filters = [
+      |    {
+      |      trace {
+      |        includes = [ "*" ]
+      |        excludes = [ "non-tracked-trace"]
+      |      }
+      |    }
+      |  ]
+      |  precision {
+      |    default-histogram-precision {
+      |      highest-trackable-value = 3600000000000
+      |      significant-value-digits = 2
+      |    }
+      |
+      |    default-min-max-counter-precision {
+      |      refresh-interval = 1 second
+      |      highest-trackable-value = 999999999
+      |      significant-value-digits = 2
+      |    }
+      |  }
+      |}
+    """.stripMargin))
+
+  "the TraceMetrics" should {
+    "record the elapsed time between a trace creation and finish" in {
+      for (repetitions ← 1 to 10) {
+        TraceRecorder.withNewTraceContext("record-elapsed-time") {
+          TraceRecorder.finish()
+        }
+      }
+
+      val snapshot = takeSnapshotOf("record-elapsed-time")
+      snapshot.elapsedTime.numberOfMeasurements should be(10)
+      snapshot.segments shouldBe empty
+    }
+
+    "record the elapsed time for segments that occur inside a given trace" in {
+      TraceRecorder.withNewTraceContext("trace-with-segments") {
+        val segmentHandle = TraceRecorder.startSegment(TraceMetricsTestSegment("test-segment"))
+        segmentHandle.get.finish()
+        TraceRecorder.finish()
+      }
+
+      val snapshot = takeSnapshotOf("trace-with-segments")
+      snapshot.elapsedTime.numberOfMeasurements should be(1)
+      snapshot.segments.size should be(1)
+      snapshot.segments(TraceMetricsTestSegment("test-segment")).numberOfMeasurements should be(1)
+    }
+
+    "record the elapsed time for segments that finish after their correspondent trace has finished" in {
+      val segmentHandle = TraceRecorder.withNewTraceContext("closing-segment-after-trace") {
+        val sh = TraceRecorder.startSegment(TraceMetricsTestSegment("test-segment"))
+        TraceRecorder.finish()
+        sh
+      }
+
+      val beforeFinishSegmentSnapshot = takeSnapshotOf("closing-segment-after-trace")
+      beforeFinishSegmentSnapshot.elapsedTime.numberOfMeasurements should be(1)
+      beforeFinishSegmentSnapshot.segments.size should be(0)
+
+      segmentHandle.get.finish()
+
+      val afterFinishSegmentSnapshot = takeSnapshotOf("closing-segment-after-trace")
+      afterFinishSegmentSnapshot.elapsedTime.numberOfMeasurements should be(0)
+      afterFinishSegmentSnapshot.segments.size should be(1)
+      afterFinishSegmentSnapshot.segments(TraceMetricsTestSegment("test-segment")).numberOfMeasurements should be(1)
+    }
+  }
+
+  case class TraceMetricsTestSegment(name: String) extends SegmentIdentity
+
+  def takeSnapshotOf(traceName: String): TraceMetricsSnapshot = {
+    val recorder = Kamon(Metrics).register(TraceMetrics(traceName), TraceMetrics.Factory)
+    recorder.get.collect(CollectionContext.default)
+  }
+}