CE3: Use twitter-util Time and Stopwatch for Clock implementation.

Allows using the twitter-util testing facilities.

Author: dangerousben

effect3/src/main/scala/io/catbird/util/effect/RerunnableInstances.scala

@@ -2,12 +2,11 @@ package io.catbird.util.effect
 
 import cats.effect.Clock
 import cats.effect.kernel.{ MonadCancel, Outcome, Sync }
-import com.twitter.util.{ Future, Monitor }
+import com.twitter.util.{ Future, Monitor, Stopwatch, Time }
 import io.catbird.util.{ Rerunnable, RerunnableMonadError }
 
 import java.lang.Throwable
 import java.util.concurrent.TimeUnit
-import java.lang.System
 
 import scala.Unit
 import scala.concurrent.duration.FiniteDuration
@@ -24,10 +23,10 @@ trait RerunnableInstances {
         Rerunnable(thunk)
 
       final override def realTime: Rerunnable[FiniteDuration] =
-        Rerunnable(FiniteDuration(System.currentTimeMillis(), TimeUnit.MILLISECONDS))
+        Rerunnable(FiniteDuration(Time.nowNanoPrecision.inNanoseconds, TimeUnit.NANOSECONDS))
 
       final override def monotonic: Rerunnable[FiniteDuration] =
-        Rerunnable(FiniteDuration(System.nanoTime(), TimeUnit.NANOSECONDS))
+        Rerunnable(FiniteDuration(Stopwatch.timeNanos(), TimeUnit.NANOSECONDS))
 
       final override def forceR[A, B](fa: Rerunnable[A])(fb: Rerunnable[B]): Rerunnable[B] =
         fa.liftToTry.flatMap { resultA =>

effect3/src/test/scala/io/catbird/util/effect/RerunnableClockSuite.scala

@@ -1,21 +1,37 @@
 package io.catbird.util.effect
 
-import cats.effect.MonadCancel
+import cats.effect.kernel.{ Clock, MonadCancel, Outcome }
 import cats.effect.kernel.testkit.SyncTypeGenerators
 import cats.effect.laws.SyncTests
 import cats.instances.either._
 import cats.instances.int._
 import cats.instances.tuple._
 import cats.instances.unit._
 import cats.laws.discipline.arbitrary._
-import com.twitter.util.{ Await, Monitor, Throw }
+import com.twitter.util.{ Await, Monitor, Throw, Time }
 import io.catbird.util.Rerunnable
 
 class RerunnableSuite extends BaseLawSuite with SyncTypeGenerators with Runners {
 
   // This includes tests for Clock, MonadCancel, and MonadError
   checkAll("Rerunnable[Int]", SyncTests[Rerunnable].sync[Int, Int, Int])
 
+  test("Retrieval of real time") {
+    val nanos = 123456789L
+    val result = Time.withTimeAt(Time.fromNanoseconds(nanos)) { _ =>
+      unsafeRun(Clock[Rerunnable].realTime.map(_.toNanos))
+    }
+    assert(result == Outcome.succeeded(Some(nanos)))
+  }
+
+  test("Retrieval of monotonic time") {
+    val nanos = 123456789L
+    val result = Time.withTimeAt(Time.fromNanoseconds(nanos)) { _ =>
+      unsafeRun(Clock[Rerunnable].monotonic.map(_.toNanos))
+    }
+    assert(result == Outcome.succeeded(Some(nanos)))
+  }
+
   test("Exceptions thrown by release are handled by Monitor") {
     val useException = new Exception("thrown by use")
     val releaseException = new Exception("thrown by release")