allow metric filtering when adding a metrics reporter

1 files changed, 114 insertions, 0 deletions

diff --git a/kamon-core-tests/src/test/scala/kamon/ReporterRegistrySpec.scala b/kamon-core-tests/src/test/scala/kamon/ReporterRegistrySpec.scala
new file mode 100644
index 00000000..d17c0f09
--- /dev/null
+++ b/kamon-core-tests/src/test/scala/kamon/ReporterRegistrySpec.scala
@@ -0,0 +1,114 @@
+package kamon
+
+import com.typesafe.config.Config
+import kamon.metric.PeriodSnapshot
+import kamon.testkit.Reconfigure
+import org.scalatest.concurrent.Eventually
+import org.scalatest.{BeforeAndAfterAll, Matchers, WordSpec}
+
+class ReporterRegistrySpec extends WordSpec with Matchers with Reconfigure with Eventually with BeforeAndAfterAll  {
+  "The ReporterRegistry" when {
+    "working with metrics reporters" should {
+      "report all metrics if no filters are applied" in {
+        Kamon.counter("test.hello").increment()
+        Kamon.counter("test.world").increment()
+        Kamon.counter("other.hello").increment()
+
+        val reporter = new SeenMetricsReporter()
+        val subscription = Kamon.addReporter(reporter, "reporter-registry-spec")
+
+        eventually {
+          reporter.snapshotCount() should be >= 1
+          reporter.metrics() should contain allOf(
+            "test.hello",
+            "test.world",
+            "other.hello"
+          )
+        }
+
+        subscription.cancel()
+      }
+
+      "default to deny all metrics if a provided filter name doesn't exist" in {
+        Kamon.counter("test.hello").increment()
+        Kamon.counter("test.world").increment()
+        Kamon.counter("other.hello").increment()
+
+        val reporter = new SeenMetricsReporter()
+        val subscription = Kamon.addReporter(reporter, "reporter-registry-spec", "does-not-exist")
+
+        eventually {
+          reporter.snapshotCount() should be >= 1
+          reporter.metrics() shouldBe empty
+        }
+
+        subscription.cancel()
+      }
+
+      "apply existent filters" in {
+        Kamon.counter("test.hello").increment()
+        Kamon.counter("test.world").increment()
+        Kamon.counter("other.hello").increment()
+
+        val reporter = new SeenMetricsReporter()
+        val subscription = Kamon.addReporter(reporter, "reporter-registry-spec", "real-filter")
+
+        eventually {
+          reporter.snapshotCount() should be >= 1
+          reporter.metrics() should contain allOf(
+            "test.hello",
+            "test.world"
+          )
+        }
+
+        subscription.cancel()
+      }
+    }
+  }
+
+
+  override protected def beforeAll(): Unit = {
+    applyConfig(
+      """
+        |kamon {
+        |  metric.tick-interval = 10 millis
+        |
+        |  util.filters {
+        |    real-filter {
+        |      includes = [ "test**" ]
+        |    }
+        |  }
+        |}
+        |
+    """.stripMargin
+    )
+  }
+
+
+  override protected def afterAll(): Unit = {
+    resetConfig()
+  }
+
+  abstract class DummyReporter extends MetricReporter {
+    override def start(): Unit = {}
+    override def stop(): Unit = {}
+    override def reconfigure(config: Config): Unit = {}
+  }
+
+  class SeenMetricsReporter extends DummyReporter {
+    @volatile private var count = 0
+    @volatile private var seenMetrics = Seq.empty[String]
+
+    override def reportPeriodSnapshot(snapshot: PeriodSnapshot): Unit = {
+      import snapshot.metrics._
+      count += 1
+      seenMetrics = counters.map(_.name) ++ histograms.map(_.name) ++ gauges.map(_.name) ++ rangeSamplers.map(_.name)
+    }
+
+    def metrics(): Seq[String] =
+      seenMetrics
+
+    def snapshotCount(): Int =
+      count
+  }
+}