1 files changed, 64 insertions, 0 deletions
diff --git a/kamon-core-tests/src/test/scala/kamon/trace/SpanMetrics.scala b/kamon-core-tests/src/test/scala/kamon/trace/SpanMetrics.scala
new file mode 100644
index 00000000..9ecffb24
--- /dev/null
+++ b/kamon-core-tests/src/test/scala/kamon/trace/SpanMetrics.scala
@@ -0,0 +1,64 @@
+package kamon.trace
+
+import kamon.Kamon
+import kamon.Kamon.buildSpan
+import kamon.metric._
+import org.scalatest.{Matchers, WordSpecLike}
+
+class SpanMetrics extends WordSpecLike with Matchers {
+  import SpanMetricsTestHelper._
+
+  val errorTag = "error" -> "true"
+  val histogramMetric: HistogramMetric = Kamon.histogram("span.elapsed-time")
+
+  "Span Metrics" should {
+    "be recorded for successeful execution" in {
+      val operation = "span-success"
+      val operationTag = "operation" -> operation
+
+      buildSpan(operation)
+        .start()
+        .finish()
+
+      val histogram = histogramMetric.refine(operationTag)
+      histogram.distribution().count === 1
+
+      val errorHistogram = histogramMetric.refine(Map(operationTag, errorTag)).distribution()
+      errorHistogram.count === 0
+
+    }
+
+    "record correctly error latency and count" in {
+      val operation = "span-failure"
+      val operationTag = "operation" -> operation
+
+      buildSpan(operation)
+        .start()
+        .addSpanTag("error", true)
+        .finish()
+
+      val histogram = histogramMetric.refine(operationTag)
+      histogram.distribution().count === 0
+
+      val errorHistogram = histogramMetric.refine(operationTag, errorTag).distribution()
+      errorHistogram.count === 1
+
+    }
+  }
+
+}
+
+object SpanMetricsTestHelper {
+
+  implicit class HistogramMetricSyntax(histogram: Histogram) {
+    def distribution(resetState: Boolean = true): Distribution =
+      histogram match {
+        case hm: HistogramMetric    => hm.refine(Map.empty[String, String]).distribution(resetState)
+        case h: AtomicHdrHistogram  => h.snapshot(resetState).distribution
+        case h: HdrHistogram        => h.snapshot(resetState).distribution
+      }
+  }
+}
+
+
+