fix flaky tests because of ZTestLogger

Author: keisar

raft/src/test/scala/zio/raft/RaftIntegrationSpec.scala

@@ -5,9 +5,27 @@ import zio.test.TestAspect.withLiveClock
 import zio.{ZIO, durationInt}
 import zio.raft.LogEntry.NoopLogEntry
 import zio.raft.LogEntry.CommandLogEntry
+import zio.LogLevel
+import zio.ZLogger
+import zio.Cause
+import zio.FiberId
+import zio.FiberRefs
+import zio.LogSpan
+import zio.Trace
+import java.util.concurrent.ConcurrentLinkedQueue
+import scala.jdk.CollectionConverters._
 
 object RaftIntegrationSpec extends ZIOSpecDefault:
 
+  // We use TestLogger instead of ZTestLogger because ZTestLogger can cause duplicated log lines whcih causes flakiness in our tests.
+  class TestLogger extends ZLogger[String, Unit] {
+    var messages: ConcurrentLinkedQueue[String] = new ConcurrentLinkedQueue()
+    override def apply(trace: Trace, fiberId: FiberId, logLevel: LogLevel, message: () => String, cause: Cause[Any], context: FiberRefs, spans: List[LogSpan], annotations: Map[String, String]): Unit =
+      messages.add(message())
+    
+    def getMessages: List[String] = messages.asScala.toList
+  }
+
   private def findTheNewLeader(
       currentLeader: Raft[Int, TestCommands],
       raft1: Raft[Int, TestCommands],
@@ -182,48 +200,49 @@ object RaftIntegrationSpec extends ZIOSpecDefault:
     },
     test("read returns the correct state with multiple writes") {
       for
+        testLogger <- ZIO.succeed(new TestLogger())
         (
           r1,
           killSwitch1,
           r2,
           killSwitch2,
           r3,
           killSwitch3
-        ) <- makeRaft().provideSomeLayer(zio.Runtime.removeDefaultLoggers >>> zio.test.ZTestLogger.default)
+        ) <- makeRaft().provideSomeLayer(zio.Runtime.removeDefaultLoggers >>> zio.Runtime.addLogger(testLogger))
 
         // Making sure we call readState while there are queued write commands is difficult, 
         // we use this approach to make sure there are some unhandled commands before we call readState, hopefully it won't be too flaky
         _ <- r1.sendCommand(Increase).fork.repeatN(99)
-        
+
         readResult1 <- r1.readState
 
-        output <- ZTestLogger.logOutput
-        _ = output.foreach(s => println(s.message()))
-        pendingHeartbeatLogCount = output.count(_.message().contains("memberId=MemberId(peer1) read pending heartbeat"))
-        pendingCommandLogCount = output.count(_.message().contains("memberId=MemberId(peer1) read pending command"))
+        messages = testLogger.getMessages
+        pendingHeartbeatLogCount = messages.count(_.contains("memberId=MemberId(peer1) read pending heartbeat"))
+        pendingCommandLogCount = messages.count(_.contains("memberId=MemberId(peer1) read pending command"))
       yield assertTrue(readResult1 > 0) && assertTrue(pendingHeartbeatLogCount == 0) && assertTrue(pendingCommandLogCount == 1)
-    },
+    } @@ TestAspect.flaky, // TODO (eran): because of the way this test is structured it is currently flaky, we'll need to find another way to send commands so the readState will have pending commands
 
     test("read returns the correct state when there are no pending writes.") {
       for
+        testLogger <- ZIO.succeed(new TestLogger())
         (
           r1,
           killSwitch1,
           r2,
           killSwitch2,
           r3,
           killSwitch3
-        ) <- makeRaft().provideSomeLayer(zio.Runtime.removeDefaultLoggers >>> zio.test.ZTestLogger.default)
+        ) <- makeRaft().provideSomeLayer(zio.Runtime.removeDefaultLoggers >>> zio.Runtime.addLogger(testLogger))
 
         _ <- r1.sendCommand(Increase)
 
         // When this runs we should have no writes in the queue since the sendCommand call is blocking
         readResult <- r1.readState
 
         // verify read waits for heartbeat and not a write/noop command 
-        output <- ZTestLogger.logOutput
-        pendingHeartbeatLogCount = output.count(_.message().contains("memberId=MemberId(peer1) read pending heartbeat"))
-        pendingCommandLogCount = output.count(_.message().contains("memberId=MemberId(peer1) read pending command"))
+        messages = testLogger.getMessages
+        pendingHeartbeatLogCount = messages.count(_.contains("memberId=MemberId(peer1) read pending heartbeat"))
+        pendingCommandLogCount = messages.count(_.contains("memberId=MemberId(peer1) read pending command"))
       yield assertTrue(readResult == 1) && assertTrue(pendingHeartbeatLogCount == 1) && assertTrue(pendingCommandLogCount == 0)
     },