Remove test warning suppressions, fix all resulting warnings

build.sbt

@@ -193,32 +193,21 @@ lazy val sharedSettings = pgpSettings ++ Seq(
     "-Xlint:infer-any",
     "-Wnonunit-statement"
   ),
-  // Disabled from tpolecat for test compilation:
-  // -Wunused:patvars triggers on for-comprehension loop vars in tests (pre-existing pattern)
-  // -Xlint:constant triggers on intentional overflow tests (e.g. Long.MaxValue + 1)
-  Test / scalacOptions --= {
-    CrossVersion.partialVersion(scalaVersion.value) match {
-      case Some((2, 13)) => Seq("-Wunused:patvars", "-Xlint:constant")
-      case Some((2, 12)) => Seq("-Ywarn-unused:patvars")
-      case _ => Seq.empty
-    }
-  },
   // Turning off fatal warnings for doc generation
   Compile / doc / tpolecatExcludeOptions ++= ScalacOptions.defaultConsoleExclude,
   // Silence everything in auto-generated files
   scalacOptions ++= {
     if (isDotty.value)
-      Seq.empty
+      Seq("-Wconf:msg=method getId in class Thread is deprecated:s")
     else
       Seq("-P:silencer:pathFilters=.*[/]src_managed[/].*")
   },
-  scalacOptions --= {
+  // Disable unused locals check in Test for Scala 3 (generated doctest files trigger false positives)
+  Test / scalacOptions ++= {
     if (isDotty.value)
-      // tpolecat uses -Werror in Scala 3; disable fatal warnings
-      // so that pre-existing value-discard and similar patterns don't break Scala 3 builds
-      Seq("-Werror")
+      Seq("-Wconf:msg=unused local definition:s")
     else
-      Seq()
+      Seq.empty
   },
   // Syntax improvements, linting, etc.
   libraryDependencies ++= {

monix-eval/shared/src/main/scala/monix/eval/Task.scala

@@ -1603,7 +1603,7 @@ sealed abstract class Task[+A] extends Serializable with TaskDeprecated.BinCompa
     *     var line: String = ""
     *     while (line != null) {
     *       line = in.readLine()
-    *       if (line != null) buffer.append(line)
+    *       if (line != null) buffer.append(line): Unit
     *     }
     *
     *     buffer.toString

monix-eval/shared/src/main/scala/monix/eval/internal/TaskConversions.scala

@@ -184,7 +184,7 @@ private[eval] object TaskConversions {
     def run(): Unit = {
       if (canCall) {
         canCall = false
-        if (conn ne null) conn.pop()
+        if (conn ne null) conn.pop(): Unit
         cb(value)
         value = null
       }

monix-eval/shared/src/main/scala/monix/eval/internal/TaskCreate.scala

@@ -219,7 +219,7 @@ private[eval] object TaskCreate {
 
     private def startExecution(): Unit = {
       // Cleanup of the current finalizer
-      if (shouldPop) ctx.connection.pop()
+      if (shouldPop) ctx.connection.pop(): Unit
       // Optimization — if the callback was called on the same thread
       // where it was created, then we are not going to fork
       // This is not safe to do when localContextPropagation enabled

monix-eval/shared/src/main/scala/monix/eval/internal/TaskFromFuture.scala

@@ -145,7 +145,7 @@ private[eval] object TaskFromFuture {
       }
 
       def run(): Unit = {
-        if (conn ne null) conn.pop()
+        if (conn ne null) conn.pop(): Unit
         val v = value
         value = null
         cb(v)

monix-eval/shared/src/test/scala/monix/eval/TaskExecuteWithOptionsSuite.scala

@@ -31,7 +31,7 @@ object TaskExecuteWithOptionsSuite extends BaseTestSuite {
     val f = task.runToFuture
     s.tick()
 
-    val Some(Success((opt1, opt2))) = f.value
+    val Some(Success((opt1, opt2))) = f.value: @unchecked
     assert(opt1.localContextPropagation, "opt1.localContextPropagation")
     assert(!opt2.localContextPropagation, "!opt2.localContextPropagation")
   }

monix-eval/shared/src/test/scala/monix/eval/TaskFlatMapSuite.scala

@@ -23,11 +23,13 @@ import monix.execution.Callback
 import monix.execution.atomic.{Atomic, AtomicInt}
 import monix.execution.exceptions.DummyException
 import monix.execution.internal.Platform
+
+import scala.annotation.unused
 import scala.util.{Failure, Random, Success, Try}
 
 object TaskFlatMapSuite extends BaseTestSuite {
   test("runAsync flatMap loop is not cancelable if autoCancelableRunLoops=false") { implicit s =>
-    implicit val opts = Task.defaultOptions.disableAutoCancelableRunLoops
+    implicit val opts: Task.Options = Task.defaultOptions.disableAutoCancelableRunLoops
     val maxCount = Platform.recommendedBatchSize * 4
 
     def loop(count: AtomicInt): Task[Unit] =
@@ -77,7 +79,7 @@ object TaskFlatMapSuite extends BaseTestSuite {
         Task.unit.flatMap(_ => loop(count))
 
     val atomic = Atomic(0)
-    var result = Option.empty[Try[Unit]]
+    @unused var result  = Option.empty[Try[Unit]]
 
     val c = loop(atomic)
       .executeWithOptions(_.enableAutoCancelableRunLoops)

monix-eval/shared/src/test/scala/monix/eval/TaskMemoizeOnSuccessSuite.scala

@@ -56,7 +56,7 @@ object TaskMemoizeOnSuccessSuite extends BaseTestSuite {
   test("Task.memoizeOnSuccess should be stack safe") { implicit s =>
     val count = if (Platform.isJVM) 50000 else 5000
     var task = Task.evalAsync(1)
-    for (i <- 0 until count) task = task.memoizeOnSuccess
+    for (_ <- 0 until count) task = task.memoizeOnSuccess
 
     val f = task.runToFuture
     assertEquals(f.value, None)
@@ -68,7 +68,7 @@ object TaskMemoizeOnSuccessSuite extends BaseTestSuite {
     val count = if (Platform.isJVM) 50000 else 5000
     var task = Task.evalAsync(1)
 
-    for (i <- 0 until count) {
+    for (_ <- 0 until count) {
       task = task.memoizeOnSuccess.flatMap(x => Task.now(x))
     }
 
@@ -81,7 +81,7 @@ object TaskMemoizeOnSuccessSuite extends BaseTestSuite {
   test("Task.flatMap.memoizeOnSuccess should be stack safe, test 2") { implicit s =>
     val count = if (Platform.isJVM) 50000 else 5000
     var task = Task.evalAsync(1)
-    for (i <- 0 until count) {
+    for (_ <- 0 until count) {
       task = task.memoizeOnSuccess.flatMap(x => Task.evalAsync(x))
     }
 
@@ -171,7 +171,7 @@ object TaskMemoizeOnSuccessSuite extends BaseTestSuite {
   test("Task.eval.memoizeOnSuccess should be stack safe") { implicit s =>
     val count = if (Platform.isJVM) 50000 else 5000
     var task = Task.eval(1)
-    for (i <- 0 until count)
+    for (_ <- 0 until count)
       task = task.memoizeOnSuccess
 
     val f = task.runToFuture; s.tick()
@@ -181,7 +181,7 @@ object TaskMemoizeOnSuccessSuite extends BaseTestSuite {
   test("Task.eval.flatMap.memoizeOnSuccess should be stack safe") { implicit s =>
     val count = if (Platform.isJVM) 50000 else 5000
     var task = Task.eval(1)
-    for (i <- 0 until count) {
+    for (_ <- 0 until count) {
       task = task.memoizeOnSuccess.flatMap(x => Task.eval(x))
     }
 
@@ -242,7 +242,7 @@ object TaskMemoizeOnSuccessSuite extends BaseTestSuite {
   test("Task.evalOnce.memoizeOnSuccess should be stack safe") { implicit s =>
     val count = if (Platform.isJVM) 50000 else 5000
     var task = Task.eval(1)
-    for (i <- 0 until count) {
+    for (_ <- 0 until count) {
       task = task.memoizeOnSuccess
     }
 
@@ -253,7 +253,7 @@ object TaskMemoizeOnSuccessSuite extends BaseTestSuite {
   test("Task.evalOnce.flatMap.memoizeOnSuccess should be stack safe") { implicit s =>
     val count = if (Platform.isJVM) 50000 else 5000
     var task = Task.eval(1)
-    for (i <- 0 until count) {
+    for (_ <- 0 until count) {
       task = task.memoizeOnSuccess.flatMap(x => Task.evalOnce(x))
     }
 
@@ -297,7 +297,7 @@ object TaskMemoizeOnSuccessSuite extends BaseTestSuite {
   test("Task.now.memoizeOnSuccess should be stack safe") { implicit s =>
     val count = if (Platform.isJVM) 50000 else 5000
     var task = Task.now(1)
-    for (i <- 0 until count) {
+    for (_ <- 0 until count) {
       task = task.memoizeOnSuccess
     }
 
@@ -308,7 +308,7 @@ object TaskMemoizeOnSuccessSuite extends BaseTestSuite {
   test("Task.now.flatMap.memoizeOnSuccess should be stack safe") { implicit s =>
     val count = if (Platform.isJVM) 50000 else 5000
     var task = Task.now(1)
-    for (i <- 0 until count) {
+    for (_ <- 0 until count) {
       task = task.memoizeOnSuccess.flatMap(x => Task.now(x))
     }
 
@@ -321,7 +321,7 @@ object TaskMemoizeOnSuccessSuite extends BaseTestSuite {
   test("Task.suspend.memoizeOnSuccess should be stack safe") { implicit s =>
     val count = if (Platform.isJVM) 50000 else 5000
     var task = Task.defer(Task.now(1))
-    for (i <- 0 until count) {
+    for (_ <- 0 until count) {
       task = task.memoizeOnSuccess.map(x => x)
     }
 

monix-execution/jvm/src/main/scala/monix/execution/schedulers/AdaptedThreadPoolExecutor.scala

@@ -33,7 +33,7 @@ private[schedulers] abstract class AdaptedThreadPoolExecutor(corePoolSize: Int,
     if ((exception eq null) && r.isInstanceOf[Future[_]]) {
       try {
         val future = r.asInstanceOf[Future[_]]
-        if (future.isDone) future.get()
+        if (future.isDone) future.get(): Unit
       } catch {
         case ex: ExecutionException =>
           exception = ex.getCause

monix-execution/jvm/src/test/scala/monix/execution/FutureUtilsJVMSuite.scala

@@ -19,13 +19,13 @@ package monix.execution
 
 import java.util.concurrent.Executors
 import java.util.concurrent.atomic.AtomicLong
-
 import minitest.TestSuite
 import monix.execution.FutureUtils.extensions._
 import monix.execution.schedulers.TestScheduler
 
 import scala.concurrent.Future
 import scala.concurrent.duration._
+import scala.reflect.ClassTag
 
 object FutureUtilsJVMSuite extends TestSuite[TestScheduler] {
 
@@ -40,6 +40,10 @@ object FutureUtilsJVMSuite extends TestSuite[TestScheduler] {
 
     case class TestException() extends RuntimeException
 
+    object TestException {
+      val ct: ClassTag[TestException] = implicitly[ClassTag[TestException]]
+    }
+
     val total = new AtomicLong(0)
     val sideEffect = new AtomicLong(0)
     val error = new AtomicLong(0)
@@ -64,7 +68,7 @@ object FutureUtilsJVMSuite extends TestSuite[TestScheduler] {
         success.incrementAndGet()
         ()
       }.recover {
-        case _: TestException =>
+        case TestException.ct(_) =>
           error.incrementAndGet()
           ()
       }

monix-execution/jvm/src/test/scala/monix/execution/atomic/ConcurrentAtomicNumberSuite.scala

@@ -39,8 +39,8 @@ abstract class ConcurrentAtomicNumberSuite[A, R <: AtomicNumber[A]](
 
   test("should perform concurrent compareAndSet") {
     val r = Atomic(ev.zero)
-    val futures = for (i <- 0 until 5) yield Future {
-      for (j <- 0 until 100)
+    val futures = for (_ <- 0 until 5) yield Future {
+      for (_ <- 0 until 100)
         r.increment()
     }
 
@@ -51,7 +51,7 @@ abstract class ConcurrentAtomicNumberSuite[A, R <: AtomicNumber[A]](
 
   test("should perform concurrent getAndSet") {
     val r = Atomic(ev.zero)
-    val futures = for (i <- 0 until 5) yield Future {
+    val futures = for (_ <- 0 until 5) yield Future {
       for (j <- 0 until 100)
         r.getAndSet(ev.fromInt(j + 1))
     }
@@ -63,8 +63,8 @@ abstract class ConcurrentAtomicNumberSuite[A, R <: AtomicNumber[A]](
 
   test("should perform concurrent increment") {
     val r = Atomic(ev.zero)
-    val futures = for (i <- 0 until 5) yield Future {
-      for (j <- 0 until 100)
+    val futures = for (_ <- 0 until 5) yield Future {
+      for (_ <- 0 until 100)
         r.increment()
     }
 
@@ -75,8 +75,8 @@ abstract class ConcurrentAtomicNumberSuite[A, R <: AtomicNumber[A]](
 
   test("should perform concurrent incrementAndGet") {
     val r = Atomic(ev.zero)
-    val futures = for (i <- 0 until 5) yield Future {
-      for (j <- 0 until 100)
+    val futures = for (_ <- 0 until 5) yield Future {
+      for (_ <- 0 until 100)
         r.incrementAndGet()
     }
 
@@ -87,8 +87,8 @@ abstract class ConcurrentAtomicNumberSuite[A, R <: AtomicNumber[A]](
 
   test("should perform concurrent getAndIncrement") {
     val r = Atomic(ev.zero)
-    val futures = for (i <- 0 until 5) yield Future {
-      for (j <- 0 until 100)
+    val futures = for (_ <- 0 until 5) yield Future {
+      for (_ <- 0 until 100)
         r.getAndIncrement()
     }
 

monix-execution/jvm/src/test/scala/monix/execution/atomic/ConcurrentAtomicSuite.scala

@@ -38,8 +38,8 @@ abstract class ConcurrentAtomicSuite[A, R <: Atomic[A]](
 
   test("should perform concurrent compareAndSet") {
     val r = Atomic(zero)
-    val futures = for (i <- 0 until 5) yield Future {
-      for (j <- 0 until 100)
+    val futures = for (_ <- 0 until 5) yield Future {
+      for (_ <- 0 until 100)
         r.transform(x => valueFromInt(valueToInt(x) + 1))
     }
 
@@ -50,7 +50,7 @@ abstract class ConcurrentAtomicSuite[A, R <: Atomic[A]](
 
   test("should perform concurrent getAndSet") {
     val r = Atomic(zero)
-    val futures = for (i <- 0 until 5) yield Future {
+    val futures = for (_ <- 0 until 5) yield Future {
       for (j <- 0 until 100)
         r.getAndSet(valueFromInt(j))
     }

monix-execution/shared/src/main/scala/monix/execution/Ack.scala

@@ -213,11 +213,11 @@ object Ack {
       */
     def syncOnContinueFollow[A](p: Promise[A], value: A): Self = {
       if (source eq Continue)
-        p.trySuccess(value)
+        p.trySuccess(value): Unit
       else if (source ne Stop)
         source.onComplete { r =>
           if (r.isSuccess && (r.get eq Continue))
-            p.trySuccess(value)
+            p.trySuccess(value): Unit
         }(immediate)
       source
     }
@@ -227,11 +227,11 @@ object Ack {
       */
     def syncOnStopFollow[A](p: Promise[A], value: A): Self = {
       if (source eq Stop)
-        p.trySuccess(value)
+        p.trySuccess(value): Unit
       else if (source ne Continue)
         source.onComplete { r =>
           if (r.isSuccess && (r.get eq Stop))
-            p.trySuccess(value)
+            p.trySuccess(value): Unit
         }(immediate)
       source
     }

monix-execution/shared/src/main/scala/monix/execution/CancelableFuture.scala

@@ -128,7 +128,7 @@ sealed abstract class CancelableFuture[+A] extends Future[A] with Cancelable { s
   override final def andThen[U](pf: PartialFunction[Try[A], U])(implicit
     executor: ExecutionContext): CancelableFuture[A] =
     transformWith { r =>
-      if (pf.isDefinedAt(r)) pf(r)
+      if (pf.isDefinedAt(r)) pf(r): Unit
       this
     }
 

monix-execution/shared/src/main/scala/monix/execution/CancelablePromise.scala

@@ -242,7 +242,7 @@ object CancelablePromise {
             }
             if (errors ne null) {
               // Throws all errors as a composite
-              val x :: xs = errors.toList
+              val x :: xs = errors.toList: @unchecked
               throw Platform.composeErrors(x, xs: _*)
             }
             true

monix-execution/shared/src/test/scala/monix/execution/CancelableSuite.scala

@@ -79,7 +79,7 @@ object CancelableSuite extends SimpleTestSuite {
           assertEquals(e, dummy1)
           assertEquals(e.getSuppressed.toList, List(dummy2))
         } else {
-          val CompositeException(errors) = e
+          val CompositeException(errors) = e: @unchecked
           assertEquals(errors.toList, List(dummy1, dummy2))
         }
     }
@@ -121,7 +121,7 @@ object CancelableSuite extends SimpleTestSuite {
       assertEquals(e, dummy1)
       assertEquals(e.getSuppressed.toList, List(dummy2))
     } else {
-      val CompositeException(errors) = sc.state.lastReportedError
+      val CompositeException(errors) = sc.state.lastReportedError: @unchecked
       assertEquals(errors.toList, List(dummy1, dummy2))
     }
   }

monix-execution/shared/src/test/scala/monix/execution/cancelables/OrderedCancelableSuite.scala

@@ -107,11 +107,11 @@ object OrderedCancelableSuite extends SimpleTestSuite {
     val c2 = Cancelable { () =>
       effect = 2
     }
-    mc.orderedUpdate(c2, Long.MaxValue + 1)
+    mc.orderedUpdate(c2, Long.MinValue)
     val c3 = Cancelable { () =>
       effect = 3
     }
-    mc.orderedUpdate(c3, Long.MaxValue + 2)
+    mc.orderedUpdate(c3, Long.MinValue + 1)
     val c4 = Cancelable { () =>
       effect = 4
     }