Merge pull request #3405 from armanbilge/topic/revert-3214

Remove `IOLocal#scope`, revert #3214

build.sbt

@@ -906,8 +906,7 @@ lazy val std = crossProject(JSPlatform, JVMPlatform, NativePlatform)
         "cats.effect.std.Queue#DroppingQueue.onOfferNoCapacity"),
       // introduced by #3347
       // private stuff
-      ProblemFilters.exclude[MissingClassProblem](
-        "cats.effect.std.AtomicCell$Impl")
+      ProblemFilters.exclude[MissingClassProblem]("cats.effect.std.AtomicCell$Impl")
     )
   )
   .jsSettings(

core/shared/src/main/scala/cats/effect/IOLocal.scala

@@ -17,7 +17,6 @@
 package cats.effect
 
 import cats.data.AndThen
-import cats.syntax.functor._
 
 /**
  * [[IOLocal]] provides a handy way of manipulating a context on different scopes.
@@ -191,28 +190,6 @@ sealed trait IOLocal[A] { self =>
    */
   def getAndReset: IO[A]
 
-  /**
-   * Creates a scope with the given value. The original value is restored upon the finalization
-   * of a resource. It means all changes made inside of the resource will not be propagated to
-   * the outside.
-   *
-   * @example
-   *
-   * {{{
-   *   for {
-   *     local <- IOLocal(42)
-   *     _     <- local.get // returns 42
-   *     _     <- local.scope(current => current + 1).surround(local.getAndSet(1)) // returns 43
-   *     _     <- local.get // returns 42, even though 1 was set inside of the resource
-   *   } yield ()
-   * }}}
-   *
-   * @param f
-   *   the function to make a new scope
-   */
-  final def scope(value: A): Resource[IO, Unit] =
-    Resource.make(getAndSet(value))(p => set(p)).void
-
   /**
    * Creates a lens to a value of some type `B` from current value and two functions: getter and
    * setter.

tests/shared/src/test/scala/cats/effect/IOLocalSpec.scala

@@ -17,8 +17,6 @@
 package cats
 package effect
 
-import cats.syntax.semigroup._
-
 import scala.annotation.tailrec
 
 class IOLocalSpec extends BaseSpec {
@@ -79,7 +77,7 @@ class IOLocalSpec extends BaseSpec {
     }
   }
 
-  private def ioLocalTests[A, B: Semigroup, C: Eq: Show](
+  private def ioLocalTests[A, B, C: Eq: Show](
       name: String,
       localF: A => IO[(IOLocal[B], IOLocal[C])]
   )(
@@ -160,18 +158,6 @@ class IOLocalSpec extends BaseSpec {
       io must completeAs(checkA(initial))
     }
 
-    "do not leak internal updates outside of a scope" in ticked { implicit ticker =>
-      val io = localF(initial).flatMap {
-        case (writer, reader) =>
-          for {
-            inside <- writer.scope(update).surround(reader.get <* writer.set(update |+| update))
-            outside <- reader.get
-          } yield (inside, outside)
-      }
-
-      io must completeAs((checkB(update), checkA(initial)))
-    }
-
   }
 
 }