move alignment and duration utilities to the companion object

1 files changed, 39 insertions, 0 deletions

diff --git a/kamon-core-tests/src/test/scala/kamon/util/ClockSpec.scala b/kamon-core-tests/src/test/scala/kamon/util/ClockSpec.scala
new file mode 100644
index 00000000..5f83d22c
--- /dev/null
+++ b/kamon-core-tests/src/test/scala/kamon/util/ClockSpec.scala
@@ -0,0 +1,39 @@
+package kamon.util
+
+import java.time.{Duration, Instant}
+
+import kamon.util
+import org.scalatest.{Matchers, WordSpec}
+
+class ClockSpec extends WordSpec with Matchers {
+  "the Clock" should {
+    "generate nanosecond precision Instants" in {
+      newClock().instant().getNano() % MicrosInSecond shouldNot be(0)
+    }
+
+    "turn Instants into micros" in {
+      Clock.toEpochMicros(Instant.parse("2017-12-18T08:39:59.000000000Z")) shouldBe 1513586399000000L
+      Clock.toEpochMicros(Instant.parse("2017-12-18T08:39:59.000000010Z")) shouldBe 1513586399000000L
+      Clock.toEpochMicros(Instant.parse("2017-12-18T08:39:59.987654321Z")) shouldBe 1513586399987654L
+      Clock.toEpochMicros(Instant.parse("2017-12-18T08:39:59.987000000Z")) shouldBe 1513586399987000L
+    }
+
+    "calculate nanos between two Instants" in {
+      Clock.nanosBetween(Instant.parse("2017-12-18T08:39:59.987654321Z"), Instant.parse("2017-12-18T08:39:59.987654322Z")) shouldBe 1
+      Clock.nanosBetween(Instant.parse("2017-12-18T08:39:59.987654322Z"), Instant.parse("2017-12-18T08:39:59.987654321Z")) shouldBe -1
+      Clock.nanosBetween(Instant.parse("2017-12-18T08:39:59.987Z"), Instant.parse("2017-12-18T08:39:59.988Z")) shouldBe 1000000
+      Clock.nanosBetween(Instant.parse("2017-12-18T08:39:59.987654Z"), Instant.parse("2017-12-18T08:39:59.987Z")) shouldBe -654000
+    }
+
+    "calculate ticks aligned to rounded boundaries" in {
+      Clock.nextTick(Instant.parse("2017-12-18T08:39:59.999Z"), Duration.ofSeconds(10)).toString shouldBe "2017-12-18T08:40:00Z"
+      Clock.nextTick(Instant.parse("2017-12-18T08:40:00.000Z"), Duration.ofSeconds(10)).toString shouldBe "2017-12-18T08:40:10Z"
+      Clock.nextTick(Instant.parse("2017-12-18T08:39:14.906Z"), Duration.ofSeconds(10)).toString shouldBe "2017-12-18T08:39:20Z"
+    }
+  }
+
+  val MicrosInSecond = 1000000
+
+  def newClock(): Clock =
+    new util.Clock.Default()
+}