From 1a079458611f4428fe5d195dd850e7868d49757d Mon Sep 17 00:00:00 2001
From: xuwei-k <6b656e6a69@gmail.com>
Date: Sun, 10 Sep 2023 11:02:41 +0900
Subject: [PATCH 1/2] add explicit type

---
 .../src/main/scala/cats/effect/IOFiber.scala   |  3 ++-
 .../main/scala/cats/effect/kernel/Async.scala  | 10 +++++-----
 .../main/scala/cats/effect/kernel/Clock.scala  | 18 ++++++++++--------
 .../scala/cats/effect/kernel/GenTemporal.scala | 10 +++++-----
 .../scala/cats/effect/kernel/Resource.scala    |  8 ++++----
 .../main/scala/cats/effect/kernel/Sync.scala   | 14 +++++++-------
 .../scala/cats/effect/laws/AsyncTests.scala    |  5 +++--
 .../scala/cats/effect/laws/ClockTests.scala    |  4 ++--
 .../scala/cats/effect/laws/GenSpawnTests.scala |  5 +++--
 .../cats/effect/laws/GenTemporalTests.scala    |  5 +++--
 .../cats/effect/laws/MonadCancelTests.scala    |  3 ++-
 .../scala/cats/effect/laws/SyncTests.scala     |  3 ++-
 .../scala/cats/effect/laws/UniqueTests.scala   |  4 ++--
 .../cats/effect/IOPlatformSpecification.scala  |  2 +-
 .../cats/effect/std/DeferredJVMSpec.scala      |  4 ++--
 .../src/test/scala/cats/effect/IOSpec.scala    |  6 ++++--
 16 files changed, 57 insertions(+), 47 deletions(-)

diff --git a/core/shared/src/main/scala/cats/effect/IOFiber.scala b/core/shared/src/main/scala/cats/effect/IOFiber.scala
index 039f73c3cb..f574b0894d 100644
--- a/core/shared/src/main/scala/cats/effect/IOFiber.scala
+++ b/core/shared/src/main/scala/cats/effect/IOFiber.scala
@@ -527,7 +527,8 @@ private final class IOFiber[A](
           masks += 1
           val id = masks
           val poll = new Poll[IO] {
-            def apply[B](ioa: IO[B]) = IO.Uncancelable.UnmaskRunLoop(ioa, id, IOFiber.this)
+            def apply[B](ioa: IO[B]): IO[B] =
+              IO.Uncancelable.UnmaskRunLoop(ioa, id, IOFiber.this)
           }
 
           val next =
diff --git a/kernel/shared/src/main/scala/cats/effect/kernel/Async.scala b/kernel/shared/src/main/scala/cats/effect/kernel/Async.scala
index 25a1599928..32be6cddeb 100644
--- a/kernel/shared/src/main/scala/cats/effect/kernel/Async.scala
+++ b/kernel/shared/src/main/scala/cats/effect/kernel/Async.scala
@@ -406,7 +406,7 @@ object Async {
     implicit protected def F: Async[F]
 
     override protected final def delegate = super.delegate
-    override protected final def C = F
+    override protected final def C: Clock[F] = F
 
     override def unique: OptionT[F, Unique.Token] =
       delay(new Unique.Token())
@@ -477,7 +477,7 @@ object Async {
     implicit protected def F: Async[F]
 
     override protected final def delegate = super.delegate
-    override protected final def C = F
+    override protected final def C: Clock[F] = F
 
     override def unique: EitherT[F, E, Unique.Token] =
       delay(new Unique.Token())
@@ -549,7 +549,7 @@ object Async {
     implicit protected def F: Async[F]
 
     override protected final def delegate = super.delegate
-    override protected final def C = F
+    override protected final def C: Clock[F] = F
 
     override def unique: IorT[F, L, Unique.Token] =
       delay(new Unique.Token())
@@ -620,7 +620,7 @@ object Async {
     implicit protected def F: Async[F]
 
     override protected final def delegate = super.delegate
-    override protected final def C = F
+    override protected final def C: Clock[F] = F
 
     override def unique: WriterT[F, L, Unique.Token] =
       delay(new Unique.Token())
@@ -688,7 +688,7 @@ object Async {
     implicit protected def F: Async[F]
 
     override protected final def delegate = super.delegate
-    override protected final def C = F
+    override protected final def C: Clock[F] = F
 
     override def unique: Kleisli[F, R, Unique.Token] =
       delay(new Unique.Token())
diff --git a/kernel/shared/src/main/scala/cats/effect/kernel/Clock.scala b/kernel/shared/src/main/scala/cats/effect/kernel/Clock.scala
index a77ad08ba3..2fdef6645b 100644
--- a/kernel/shared/src/main/scala/cats/effect/kernel/Clock.scala
+++ b/kernel/shared/src/main/scala/cats/effect/kernel/Clock.scala
@@ -64,7 +64,7 @@ object Clock {
       implicit F0: Monad[F],
       C0: Clock[F]): Clock[OptionT[F, *]] =
     new OptionTClock[F] {
-      def applicative = OptionT.catsDataMonadForOptionT(F)
+      def applicative: Applicative[OptionT[F, *]] = OptionT.catsDataMonadForOptionT(F)
       implicit override def F: Monad[F] = F0
       implicit override def C: Clock[F] = C0
     }
@@ -73,7 +73,7 @@ object Clock {
       implicit F0: Monad[F],
       C0: Clock[F]): Clock[EitherT[F, E, *]] =
     new EitherTClock[F, E] {
-      def applicative = EitherT.catsDataMonadErrorForEitherT(F)
+      def applicative: Applicative[EitherT[F, E, *]] = EitherT.catsDataMonadErrorForEitherT(F)
       implicit override def F: Monad[F] = F0
       implicit override def C: Clock[F] = C0
     }
@@ -82,7 +82,8 @@ object Clock {
       implicit F0: Monad[F],
       C0: Clock[F]): Clock[StateT[F, S, *]] =
     new StateTClock[F, S] {
-      def applicative = IndexedStateT.catsDataMonadForIndexedStateT(F)
+      def applicative: Applicative[IndexedStateT[F, S, S, *]] =
+        IndexedStateT.catsDataMonadForIndexedStateT(F)
       implicit override def F: Monad[F] = F0
       implicit override def C: Clock[F] = C0
     }
@@ -92,7 +93,7 @@ object Clock {
       C0: Clock[F],
       L0: Monoid[L]): Clock[WriterT[F, L, *]] =
     new WriterTClock[F, L] {
-      def applicative = WriterT.catsDataMonadForWriterT(F, L)
+      def applicative: Applicative[WriterT[F, L, *]] = WriterT.catsDataMonadForWriterT(F, L)
       implicit override def F: Monad[F] = F0
       implicit override def C: Clock[F] = C0
 
@@ -105,7 +106,7 @@ object Clock {
       C0: Clock[F],
       L0: Semigroup[L]): Clock[IorT[F, L, *]] =
     new IorTClock[F, L] {
-      def applicative = IorT.catsDataMonadErrorForIorT(F, L)
+      def applicative: Applicative[IorT[F, L, *]] = IorT.catsDataMonadErrorForIorT(F, L)
       implicit override def F: Monad[F] = F0
       implicit override def C: Clock[F] = C0
 
@@ -116,7 +117,7 @@ object Clock {
       implicit F0: Monad[F],
       C0: Clock[F]): Clock[Kleisli[F, R, *]] =
     new KleisliClock[F, R] {
-      def applicative = Kleisli.catsDataMonadForKleisli(F)
+      def applicative: Applicative[Kleisli[F, R, *]] = Kleisli.catsDataMonadForKleisli(F)
       implicit override def F: Monad[F] = F0
       implicit override def C: Clock[F] = C0
     }
@@ -126,7 +127,7 @@ object Clock {
       C0: Clock[F],
       D0: Defer[F]): Clock[ContT[F, R, *]] =
     new ContTClock[F, R] {
-      def applicative = ContT.catsDataContTMonad(D)
+      def applicative: Applicative[ContT[F, R, *]] = ContT.catsDataContTMonad(D)
       implicit override def F: Monad[F] = F0
       implicit override def C: Clock[F] = C0
       implicit override def D: Defer[F] = D0
@@ -137,7 +138,8 @@ object Clock {
       C0: Clock[F],
       L0: Monoid[L]): Clock[ReaderWriterStateT[F, R, L, S, *]] =
     new ReaderWriterStateTClock[F, R, L, S] {
-      def applicative = IndexedReaderWriterStateT.catsDataMonadForRWST(F, L)
+      def applicative: Applicative[ReaderWriterStateT[F, R, L, S, *]] =
+        IndexedReaderWriterStateT.catsDataMonadForRWST(F, L)
       implicit override def F: Monad[F] = F0
       implicit override def C: Clock[F] = C0
 
diff --git a/kernel/shared/src/main/scala/cats/effect/kernel/GenTemporal.scala b/kernel/shared/src/main/scala/cats/effect/kernel/GenTemporal.scala
index 305cf8ece2..27cdacbf68 100644
--- a/kernel/shared/src/main/scala/cats/effect/kernel/GenTemporal.scala
+++ b/kernel/shared/src/main/scala/cats/effect/kernel/GenTemporal.scala
@@ -310,7 +310,7 @@ object GenTemporal {
       with Clock.OptionTClock[F] {
 
     implicit protected def F: GenTemporal[F, E]
-    protected def C = F
+    protected def C: Clock[F] = F
 
     override protected def delegate: MonadError[OptionT[F, *], E] =
       OptionT.catsDataMonadErrorForOptionT[F, E]
@@ -325,7 +325,7 @@ object GenTemporal {
       with Clock.EitherTClock[F, E0] {
 
     implicit protected def F: GenTemporal[F, E]
-    protected def C = F
+    protected def C: Clock[F] = F
 
     override protected def delegate: MonadError[EitherT[F, E0, *], E] =
       EitherT.catsDataMonadErrorFForEitherT[F, E, E0]
@@ -339,7 +339,7 @@ object GenTemporal {
       with Clock.IorTClock[F, L] {
 
     implicit protected def F: GenTemporal[F, E]
-    protected def C = F
+    protected def C: Clock[F] = F
 
     override protected def delegate: MonadError[IorT[F, L, *], E] =
       IorT.catsDataMonadErrorFForIorT[F, L, E]
@@ -353,7 +353,7 @@ object GenTemporal {
       with Clock.WriterTClock[F, L] {
 
     implicit protected def F: GenTemporal[F, E]
-    protected def C = F
+    protected def C: Clock[F] = F
 
     implicit protected def L: Monoid[L]
 
@@ -369,7 +369,7 @@ object GenTemporal {
       with Clock.KleisliClock[F, R] {
 
     implicit protected def F: GenTemporal[F, E]
-    protected def C = F
+    protected def C: Clock[F] = F
 
     override protected def delegate: MonadError[Kleisli[F, R, *], E] =
       Kleisli.catsDataMonadErrorForKleisli[F, R, E]
diff --git a/kernel/shared/src/main/scala/cats/effect/kernel/Resource.scala b/kernel/shared/src/main/scala/cats/effect/kernel/Resource.scala
index 36dfeb07d4..b93f73cce5 100644
--- a/kernel/shared/src/main/scala/cats/effect/kernel/Resource.scala
+++ b/kernel/shared/src/main/scala/cats/effect/kernel/Resource.scala
@@ -1223,7 +1223,7 @@ private[effect] trait ResourceHOInstances0 extends ResourceHOInstances1 {
   implicit def catsEffectAsyncForResource[F[_]](implicit F0: Async[F]): Async[Resource[F, *]] =
     new ResourceAsync[F] {
       def F = F0
-      override def applicative = this
+      override def applicative: ResourceAsync[F] = this
     }
 
   implicit def catsEffectSemigroupKForResource[F[_], A](
@@ -1242,7 +1242,7 @@ private[effect] trait ResourceHOInstances1 extends ResourceHOInstances2 {
       implicit F0: Temporal[F]): Temporal[Resource[F, *]] =
     new ResourceTemporal[F] {
       def F = F0
-      override def applicative = this
+      override def applicative: Applicative[Resource[F, *]] = this
     }
 
   implicit def catsEffectSyncForResource[F[_]](implicit F0: Sync[F]): Sync[Resource[F, *]] =
@@ -1257,7 +1257,7 @@ private[effect] trait ResourceHOInstances2 extends ResourceHOInstances3 {
       implicit F0: Concurrent[F]): Concurrent[Resource[F, *]] =
     new ResourceConcurrent[F] {
       def F = F0
-      override def applicative = this
+      override def applicative: ResourceConcurrent[F] = this
     }
 
   implicit def catsEffectClockForResource[F[_]](
@@ -1430,7 +1430,7 @@ abstract private[effect] class ResourceAsync[F[_]]
     with Async[Resource[F, *]] { self =>
   implicit protected def F: Async[F]
 
-  override def applicative = this
+  override def applicative: ResourceAsync[F] = this
 
   override def unique: Resource[F, Unique.Token] =
     Resource.unique
diff --git a/kernel/shared/src/main/scala/cats/effect/kernel/Sync.scala b/kernel/shared/src/main/scala/cats/effect/kernel/Sync.scala
index 68ad11ef65..dc63120be7 100644
--- a/kernel/shared/src/main/scala/cats/effect/kernel/Sync.scala
+++ b/kernel/shared/src/main/scala/cats/effect/kernel/Sync.scala
@@ -214,7 +214,7 @@ object Sync {
       with Clock.OptionTClock[F] {
 
     implicit protected def F: Sync[F]
-    protected def C = F
+    protected def C: Clock[F] = F
 
     def suspend[A](hint: Type)(thunk: => A): OptionT[F, A] =
       OptionT.liftF(F.suspend(hint)(thunk))
@@ -225,7 +225,7 @@ object Sync {
       with MonadCancel.EitherTMonadCancel[F, E, Throwable]
       with Clock.EitherTClock[F, E] {
     implicit protected def F: Sync[F]
-    protected def C = F
+    protected def C: Clock[F] = F
 
     def suspend[A](hint: Type)(thunk: => A): EitherT[F, E, A] =
       EitherT.liftF(F.suspend(hint)(thunk))
@@ -236,7 +236,7 @@ object Sync {
       with MonadCancel.StateTMonadCancel[F, S, Throwable]
       with Clock.StateTClock[F, S] {
     implicit protected def F: Sync[F]
-    protected def C = F
+    protected def C: Clock[F] = F
 
     def suspend[A](hint: Type)(thunk: => A): StateT[F, S, A] =
       StateT.liftF(F.suspend(hint)(thunk))
@@ -247,7 +247,7 @@ object Sync {
       with MonadCancel.WriterTMonadCancel[F, S, Throwable]
       with Clock.WriterTClock[F, S] {
     implicit protected def F: Sync[F]
-    protected def C = F
+    protected def C: Clock[F] = F
 
     def suspend[A](hint: Type)(thunk: => A): WriterT[F, S, A] =
       WriterT.liftF(F.suspend(hint)(thunk))
@@ -258,7 +258,7 @@ object Sync {
       with MonadCancel.IorTMonadCancel[F, L, Throwable]
       with Clock.IorTClock[F, L] {
     implicit protected def F: Sync[F]
-    protected def C = F
+    protected def C: Clock[F] = F
 
     def suspend[A](hint: Type)(thunk: => A): IorT[F, L, A] =
       IorT.liftF(F.suspend(hint)(thunk))
@@ -269,7 +269,7 @@ object Sync {
       with MonadCancel.KleisliMonadCancel[F, R, Throwable]
       with Clock.KleisliClock[F, R] {
     implicit protected def F: Sync[F]
-    protected def C = F
+    protected def C: Clock[F] = F
 
     def suspend[A](hint: Type)(thunk: => A): Kleisli[F, R, A] =
       Kleisli.liftF(F.suspend(hint)(thunk))
@@ -280,7 +280,7 @@ object Sync {
       with MonadCancel.ReaderWriterStateTMonadCancel[F, R, L, S, Throwable]
       with Clock.ReaderWriterStateTClock[F, R, L, S] {
     implicit protected def F: Sync[F]
-    protected def C = F
+    protected def C: Clock[F] = F
 
     def suspend[A](hint: Type)(thunk: => A): ReaderWriterStateT[F, R, L, S, A] =
       ReaderWriterStateT.liftF(F.suspend(hint)(thunk))
diff --git a/laws/shared/src/main/scala/cats/effect/laws/AsyncTests.scala b/laws/shared/src/main/scala/cats/effect/laws/AsyncTests.scala
index 45bbedd57f..7b1bbd7de1 100644
--- a/laws/shared/src/main/scala/cats/effect/laws/AsyncTests.scala
+++ b/laws/shared/src/main/scala/cats/effect/laws/AsyncTests.scala
@@ -24,6 +24,7 @@ import cats.laws.discipline.SemigroupalTests.Isomorphisms
 import org.scalacheck._
 import org.scalacheck.Prop.forAll
 import org.scalacheck.util.Pretty
+import org.typelevel.discipline.Laws
 
 import scala.concurrent.ExecutionContext
 import scala.concurrent.duration.FiniteDuration
@@ -84,7 +85,7 @@ trait AsyncTests[F[_]] extends GenTemporalTests[F, Throwable] with SyncTests[F]
 
     new RuleSet {
       val name = "async"
-      val bases = Nil
+      val bases: Seq[(String, Laws#RuleSet)] = Nil
       val parents = Seq(
         temporal[A, B, C](
           tolerance,
@@ -194,7 +195,7 @@ trait AsyncTests[F[_]] extends GenTemporalTests[F, Throwable] with SyncTests[F]
 
     new RuleSet {
       val name = "async"
-      val bases = Nil
+      val bases: Seq[(String, Laws#RuleSet)] = Nil
       val parents = Seq(
         temporal[A, B, C](tolerance)(
           implicitly[Arbitrary[A]],
diff --git a/laws/shared/src/main/scala/cats/effect/laws/ClockTests.scala b/laws/shared/src/main/scala/cats/effect/laws/ClockTests.scala
index c58871f53e..dc5178c8ba 100644
--- a/laws/shared/src/main/scala/cats/effect/laws/ClockTests.scala
+++ b/laws/shared/src/main/scala/cats/effect/laws/ClockTests.scala
@@ -29,8 +29,8 @@ trait ClockTests[F[_]] extends Laws {
   def clock(implicit exec: F[Boolean] => Prop): RuleSet = {
     new RuleSet {
       val name = "clock"
-      val bases = Nil
-      val parents = Seq()
+      val bases: Seq[(String, Laws#RuleSet)] = Nil
+      val parents: Seq[RuleSet] = Seq()
 
       val props = Seq("monotonicity" -> exec(laws.monotonicity))
     }
diff --git a/laws/shared/src/main/scala/cats/effect/laws/GenSpawnTests.scala b/laws/shared/src/main/scala/cats/effect/laws/GenSpawnTests.scala
index 44aac420e6..8ab1a64495 100644
--- a/laws/shared/src/main/scala/cats/effect/laws/GenSpawnTests.scala
+++ b/laws/shared/src/main/scala/cats/effect/laws/GenSpawnTests.scala
@@ -24,6 +24,7 @@ import cats.laws.discipline.SemigroupalTests.Isomorphisms
 import org.scalacheck._
 import org.scalacheck.Prop.forAll
 import org.scalacheck.util.Pretty
+import org.typelevel.discipline.Laws
 
 trait GenSpawnTests[F[_], E] extends MonadCancelTests[F, E] with UniqueTests[F] {
 
@@ -68,7 +69,7 @@ trait GenSpawnTests[F[_], E] extends MonadCancelTests[F, E] with UniqueTests[F]
     // these are the OLD LAWS retained only for bincompat
     new RuleSet {
       val name = "concurrent"
-      val bases = Nil
+      val bases: Seq[(String, Laws#RuleSet)] = Nil
       val parents = Seq(
         monadCancel[A, B, C](
           implicitly[Arbitrary[A]],
@@ -159,7 +160,7 @@ trait GenSpawnTests[F[_], E] extends MonadCancelTests[F, E] with UniqueTests[F]
 
     new RuleSet {
       val name = "concurrent"
-      val bases = Nil
+      val bases: Seq[(String, Laws#RuleSet)] = Nil
       val parents = Seq(
         monadCancel[A, B, C](
           implicitly[Arbitrary[A]],
diff --git a/laws/shared/src/main/scala/cats/effect/laws/GenTemporalTests.scala b/laws/shared/src/main/scala/cats/effect/laws/GenTemporalTests.scala
index 83127ae52e..c63579943c 100644
--- a/laws/shared/src/main/scala/cats/effect/laws/GenTemporalTests.scala
+++ b/laws/shared/src/main/scala/cats/effect/laws/GenTemporalTests.scala
@@ -24,6 +24,7 @@ import cats.laws.discipline.SemigroupalTests.Isomorphisms
 import org.scalacheck._
 import org.scalacheck.Prop.forAll
 import org.scalacheck.util.Pretty
+import org.typelevel.discipline.Laws
 
 import scala.concurrent.duration.FiniteDuration
 
@@ -84,7 +85,7 @@ trait GenTemporalTests[F[_], E] extends GenSpawnTests[F, E] with ClockTests[F] {
 
     new RuleSet {
       val name = "temporal"
-      val bases = Nil
+      val bases: Seq[(String, Laws#RuleSet)] = Nil
       val parents = Seq(
         spawn[A, B, C](
           implicitly[Arbitrary[A]],
@@ -177,7 +178,7 @@ trait GenTemporalTests[F[_], E] extends GenSpawnTests[F, E] with ClockTests[F] {
 
     new RuleSet {
       val name = "temporal"
-      val bases = Nil
+      val bases: Seq[(String, Laws#RuleSet)] = Nil
       val parents = Seq(
         spawn[A, B, C](
           implicitly[Arbitrary[A]],
diff --git a/laws/shared/src/main/scala/cats/effect/laws/MonadCancelTests.scala b/laws/shared/src/main/scala/cats/effect/laws/MonadCancelTests.scala
index 870815de69..f91ebfa3d5 100644
--- a/laws/shared/src/main/scala/cats/effect/laws/MonadCancelTests.scala
+++ b/laws/shared/src/main/scala/cats/effect/laws/MonadCancelTests.scala
@@ -25,6 +25,7 @@ import cats.laws.discipline.SemigroupalTests.Isomorphisms
 import org.scalacheck._
 import org.scalacheck.Prop.forAll
 import org.scalacheck.util.Pretty
+import org.typelevel.discipline.Laws
 
 trait MonadCancelTests[F[_], E] extends MonadErrorTests[F, E] {
 
@@ -111,7 +112,7 @@ trait MonadCancelTests[F[_], E] extends MonadErrorTests[F, E] {
 
     new RuleSet {
       val name = "monadCancel"
-      val bases = Nil
+      val bases: Seq[(String, Laws#RuleSet)] = Nil
       val parents = Seq(monadError[A, B, C])
 
       val props = {
diff --git a/laws/shared/src/main/scala/cats/effect/laws/SyncTests.scala b/laws/shared/src/main/scala/cats/effect/laws/SyncTests.scala
index 78af874d09..269a40a995 100644
--- a/laws/shared/src/main/scala/cats/effect/laws/SyncTests.scala
+++ b/laws/shared/src/main/scala/cats/effect/laws/SyncTests.scala
@@ -23,6 +23,7 @@ import cats.laws.discipline.SemigroupalTests.Isomorphisms
 
 import org.scalacheck._
 import org.scalacheck.Prop.forAll
+import org.typelevel.discipline.Laws
 
 trait SyncTests[F[_]]
     extends MonadCancelTests[F, Throwable]
@@ -58,7 +59,7 @@ trait SyncTests[F[_]]
 
     new RuleSet {
       val name = "sync"
-      val bases = Nil
+      val bases: Seq[(String, Laws#RuleSet)] = Nil
       val parents = Seq(
         monadCancel[A, B, C](
           implicitly[Arbitrary[A]],
diff --git a/laws/shared/src/main/scala/cats/effect/laws/UniqueTests.scala b/laws/shared/src/main/scala/cats/effect/laws/UniqueTests.scala
index 32f111a1fa..f44b470ef6 100644
--- a/laws/shared/src/main/scala/cats/effect/laws/UniqueTests.scala
+++ b/laws/shared/src/main/scala/cats/effect/laws/UniqueTests.scala
@@ -29,8 +29,8 @@ trait UniqueTests[F[_]] extends Laws {
   def unique(implicit exec: F[Boolean] => Prop): RuleSet = {
     new RuleSet {
       val name = "unique"
-      val bases = Nil
-      val parents = Seq()
+      val bases: Seq[(String, Laws#RuleSet)] = Nil
+      val parents: Seq[RuleSet] = Seq()
 
       val props = Seq("uniqueness" -> exec(laws.uniqueness))
     }
diff --git a/tests/jvm/src/test/scala/cats/effect/IOPlatformSpecification.scala b/tests/jvm/src/test/scala/cats/effect/IOPlatformSpecification.scala
index 5d095460b6..9e69674c6f 100644
--- a/tests/jvm/src/test/scala/cats/effect/IOPlatformSpecification.scala
+++ b/tests/jvm/src/test/scala/cats/effect/IOPlatformSpecification.scala
@@ -501,7 +501,7 @@ trait IOPlatformSpecification { self: BaseSpec with ScalaCheck =>
             }
           }
 
-          def makeApi(register: (Poller => Unit) => Unit) =
+          def makeApi(register: (Poller => Unit) => Unit): DummySystem.Api =
             new DummyPoller {
               def poll = IO.async_[Unit] { cb =>
                 register { poller =>
diff --git a/tests/jvm/src/test/scala/cats/effect/std/DeferredJVMSpec.scala b/tests/jvm/src/test/scala/cats/effect/std/DeferredJVMSpec.scala
index 9aa628f984..6d045b6822 100644
--- a/tests/jvm/src/test/scala/cats/effect/std/DeferredJVMSpec.scala
+++ b/tests/jvm/src/test/scala/cats/effect/std/DeferredJVMSpec.scala
@@ -47,7 +47,7 @@ abstract class BaseDeferredJVMTests(parallelism: Int)
 
   implicit val runtime: IORuntime = IORuntime.global
 
-  def before =
+  def before: Any =
     service = Executors.newFixedThreadPool(
       parallelism,
       new ThreadFactory {
@@ -61,7 +61,7 @@ abstract class BaseDeferredJVMTests(parallelism: Int)
       }
     )
 
-  def after = {
+  def after: Any = {
     service.shutdown()
     assert(service.awaitTermination(60, TimeUnit.SECONDS), "has active threads")
   }
diff --git a/tests/shared/src/test/scala/cats/effect/IOSpec.scala b/tests/shared/src/test/scala/cats/effect/IOSpec.scala
index d8152ccc81..34134247a0 100644
--- a/tests/shared/src/test/scala/cats/effect/IOSpec.scala
+++ b/tests/shared/src/test/scala/cats/effect/IOSpec.scala
@@ -24,6 +24,7 @@ import cats.kernel.laws.discipline.MonoidTests
 import cats.laws.discipline.{AlignTests, SemigroupKTests}
 import cats.laws.discipline.arbitrary._
 import cats.syntax.all._
+import cats.~>
 
 import org.scalacheck.Prop
 import org.typelevel.discipline.specs2.mutable.Discipline
@@ -1325,8 +1326,9 @@ class IOSpec extends BaseSpec with Discipline with IOPlatformSpecification {
 
       "catch exceptions in cont" in ticked { implicit ticker =>
         IO.cont[Unit, Unit](new Cont[IO, Unit, Unit] {
-          override def apply[F[_]](implicit F: MonadCancel[F, Throwable]) = { (_, _, _) =>
-            throw new Exception
+          override def apply[F[_]](implicit F: MonadCancel[F, Throwable])
+              : (Either[Throwable, Unit] => Unit, F[Unit], cats.effect.IO ~> F) => F[Unit] = {
+            (_, _, _) => throw new Exception
           }
         }).voidError must completeAs(())
       }

From 560deb0c726f781626794d130c27d232c569242a Mon Sep 17 00:00:00 2001
From: Arman Bilge <armanbilge@gmail.com>
Date: Sun, 10 Sep 2023 19:23:24 +0000
Subject: [PATCH 2/2] Remove unneeded overrides

---
 .../shared/src/main/scala/cats/effect/kernel/Resource.scala  | 5 -----
 1 file changed, 5 deletions(-)

diff --git a/kernel/shared/src/main/scala/cats/effect/kernel/Resource.scala b/kernel/shared/src/main/scala/cats/effect/kernel/Resource.scala
index b93f73cce5..6169d4ee3a 100644
--- a/kernel/shared/src/main/scala/cats/effect/kernel/Resource.scala
+++ b/kernel/shared/src/main/scala/cats/effect/kernel/Resource.scala
@@ -1223,7 +1223,6 @@ private[effect] trait ResourceHOInstances0 extends ResourceHOInstances1 {
   implicit def catsEffectAsyncForResource[F[_]](implicit F0: Async[F]): Async[Resource[F, *]] =
     new ResourceAsync[F] {
       def F = F0
-      override def applicative: ResourceAsync[F] = this
     }
 
   implicit def catsEffectSemigroupKForResource[F[_], A](
@@ -1242,7 +1241,6 @@ private[effect] trait ResourceHOInstances1 extends ResourceHOInstances2 {
       implicit F0: Temporal[F]): Temporal[Resource[F, *]] =
     new ResourceTemporal[F] {
       def F = F0
-      override def applicative: Applicative[Resource[F, *]] = this
     }
 
   implicit def catsEffectSyncForResource[F[_]](implicit F0: Sync[F]): Sync[Resource[F, *]] =
@@ -1257,7 +1255,6 @@ private[effect] trait ResourceHOInstances2 extends ResourceHOInstances3 {
       implicit F0: Concurrent[F]): Concurrent[Resource[F, *]] =
     new ResourceConcurrent[F] {
       def F = F0
-      override def applicative: ResourceConcurrent[F] = this
     }
 
   implicit def catsEffectClockForResource[F[_]](
@@ -1430,8 +1427,6 @@ abstract private[effect] class ResourceAsync[F[_]]
     with Async[Resource[F, *]] { self =>
   implicit protected def F: Async[F]
 
-  override def applicative: ResourceAsync[F] = this
-
   override def unique: Resource[F, Unique.Token] =
     Resource.unique