Merge branch 'master' into more-utils-for-optiont

# Conflicts: # tests/src/test/scala/cats/tests/OptionTSuite.scala
typelevel · Mar 12, 2020 · ff699db · ff699db
2 parents 6fa9007 + 4351ea3
commit ff699db
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diff --git a/.scalafmt.conf b/.scalafmt.conf
@@ -1,4 +1,4 @@
-version=2.3.2
+version=2.4.2
 align.openParenCallSite = true
 align.openParenDefnSite = true
 maxColumn = 120
@@ -7,3 +7,4 @@ assumeStandardLibraryStripMargin = true
 danglingParentheses = true
 rewrite.rules = [AvoidInfix, SortImports, RedundantBraces, RedundantParens, SortModifiers]
 docstrings = JavaDoc
+newlines.afterCurlyLambda = preserve
diff --git a/PROCESS.md b/PROCESS.md
@@ -18,6 +18,15 @@ When fixing typos, improving documentation or minor build fix only
 one sign-off is required (although for major edits waiting for two
  may be preferable).
 
+In some cases pull requests that don't target the master branch may be
+merged with a single sign-off from a maintainer (as long as they
+aren't also the author of the pull request). For example, backporting
+changes from master to the `scala_2.11` branch generally shouldn't
+require multiple reviews. If either the pull request author or a Cats
+maintainer thinks that a specific change should receive multiple
+approvals even though it doesn't target the master branch, their
+request should be respected.
+
 For serious emergencies or work on the build which can't easily be
 reviewed or tested, pushing directly to master may be OK (but is
 definitely not encouraged). In these cases it's best to comment in

diff --git a/alleycats-core/src/main/scala/alleycats/std/map.scala b/alleycats-core/src/main/scala/alleycats/std/map.scala
@@ -15,9 +15,9 @@ trait MapInstances {
         val gba: Eval[G[Map[K, B]]] = Always(G.pure(Map.empty))
         val gbb = Foldable
           .iterateRight(fa, gba) { (kv, lbuf) =>
-            G.map2Eval(f(kv._2), lbuf)({ (b, buf) =>
+            G.map2Eval(f(kv._2), lbuf) { (b, buf) =>
               buf + (kv._1 -> b)
-            })
+            }
           }
           .value
         G.map(gbb)(_.toMap)
@@ -67,9 +67,9 @@ trait MapInstances {
         val gba: Eval[G[Map[K, B]]] = Always(G.pure(Map.empty))
         Foldable
           .iterateRight(fa, gba) { (kv, lbuf) =>
-            G.map2Eval(f(kv._2), lbuf)({ (ob, buf) =>
+            G.map2Eval(f(kv._2), lbuf) { (ob, buf) =>
               ob.fold(buf)(b => buf + (kv._1 -> b))
-            })
+            }
           }
           .value
       }

diff --git a/alleycats-tests/js/src/test/scala/alleycats/tests/TestSettings.scala b/alleycats-tests/js/src/test/scala/alleycats/tests/TestSettings.scala
@@ -1,5 +1,4 @@
-package alleycats
-package tests
+package alleycats.tests
 
 import org.scalactic.anyvals.{PosInt, PosZDouble, PosZInt}
 import org.scalatest.matchers.should.Matchers

diff --git a/alleycats-tests/jvm/src/test/scala/alleycats/tests/TestSettings.scala b/alleycats-tests/jvm/src/test/scala/alleycats/tests/TestSettings.scala
@@ -1,5 +1,4 @@
-package alleycats
-package tests
+package alleycats.tests
 
 import org.scalactic.anyvals.{PosInt, PosZDouble, PosZInt}
 import org.scalatest.matchers.should.Matchers

diff --git a/alleycats-tests/shared/src/test/scala/alleycats/tests/AlleycatsSuite.scala b/alleycats-tests/shared/src/test/scala/alleycats/tests/AlleycatsSuite.scala
@@ -1,18 +1,15 @@
-package alleycats
-package tests
+package alleycats.tests
 
 import alleycats.std.MapInstances
 import cats._
-import cats.instances.AllInstances
-import cats.syntax.{AllSyntax, EqOps}
+import cats.instances.all._
 import cats.tests.StrictCatsEquality
 import org.scalatest.funsuite.AnyFunSuiteLike
 import org.scalatestplus.scalacheck.ScalaCheckDrivenPropertyChecks
 import org.typelevel.discipline.scalatest.FunSuiteDiscipline
 import org.scalacheck.{Arbitrary, Gen}
 import org.scalacheck.Arbitrary.arbitrary
 import org.scalatest.matchers.should.Matchers
-
 import scala.util.{Failure, Success, Try}
 
 /**
@@ -25,18 +22,12 @@ trait AlleycatsSuite
     with ScalaCheckDrivenPropertyChecks
     with FunSuiteDiscipline
     with TestSettings
-    with AllInstances
-    with AllSyntax
     with TestInstances
     with StrictCatsEquality
     with MapInstances {
   implicit override val generatorDrivenConfig: PropertyCheckConfiguration =
     checkConfiguration
 
-  // disable Eq syntax (by making `catsSyntaxEq` not implicit), since it collides
-  // with scalactic's equality
-  override def catsSyntaxEq[A: Eq](a: A): EqOps[A] = new EqOps[A](a)
-
   implicit def EqIterable[A: Eq]: Eq[Iterable[A]] = Eq.by(_.toList)
 }
 

diff --git a/alleycats-tests/shared/src/test/scala/alleycats/tests/IterableTests.scala b/alleycats-tests/shared/src/test/scala/alleycats/tests/IterableTests.scala
@@ -1,8 +1,8 @@
-package alleycats
-package tests
+package alleycats.tests
 
-import cats.{Eval, Foldable}
 import alleycats.std.all._
+import cats.{Eval, Foldable}
+import cats.instances.all._
 import cats.laws.discipline.FoldableTests
 
 class IterableTests extends AlleycatsSuite {

diff --git a/alleycats-tests/shared/src/test/scala/alleycats/tests/MapSuite.scala b/alleycats-tests/shared/src/test/scala/alleycats/tests/MapSuite.scala
@@ -1,8 +1,9 @@
 package alleycats.tests
 
-import cats.laws.discipline.arbitrary._
-import cats.laws.discipline.{SerializableTests, TraverseFilterTests}
 import cats.Traverse
+import cats.instances.all._
+import cats.laws.discipline.{SerializableTests, TraverseFilterTests}
+import cats.laws.discipline.arbitrary._
 
 class MapSuite extends AlleycatsSuite {
   checkAll("Traverse[Map[Int, *]]", SerializableTests.serializable(Traverse[Map[Int, *]]))

diff --git a/alleycats-tests/shared/src/test/scala/alleycats/tests/SetSuite.scala b/alleycats-tests/shared/src/test/scala/alleycats/tests/SetSuite.scala
@@ -1,12 +1,12 @@
 package alleycats.tests
 
 import alleycats.laws.discipline._
+import alleycats.std.all._
 import cats.Foldable
+import cats.instances.all._
 import cats.kernel.laws.discipline.SerializableTests
-import cats.laws.discipline.arbitrary._
 import cats.laws.discipline.TraverseFilterTests
-
-import alleycats.std.all._
+import cats.laws.discipline.arbitrary._
 
 class SetSuite extends AlleycatsSuite {
   checkAll("FlatMapRec[Set]", FlatMapRecTests[Set].tailRecM[Int])

diff --git a/core/src/main/scala/cats/Alternative.scala b/core/src/main/scala/cats/Alternative.scala
@@ -52,7 +52,7 @@ import simulacrum.typeclass
    * {{{
    * scala> import cats.implicits._
    * scala> val l: List[Either[String, Int]] = List(Right(1), Left("error"))
-   * scala> Alternative[List].separate(l)
+   * scala> Alternative[List].separateFoldable(l)
    * res0: (List[String], List[Int]) = (List(error),List(1))
    * }}}
    */

diff --git a/core/src/main/scala/cats/data/Cokleisli.scala b/core/src/main/scala/cats/data/Cokleisli.scala
@@ -123,14 +123,14 @@ private[data] class CokleisliMonad[F[_], A] extends Monad[Cokleisli[F, A, *]] {
     fa.map(f)
 
   def tailRecM[B, C](b: B)(fn: B => Cokleisli[F, A, Either[B, C]]): Cokleisli[F, A, C] =
-    Cokleisli({ (fa: F[A]) =>
+    Cokleisli { (fa: F[A]) =>
       @tailrec
       def loop(c: Cokleisli[F, A, Either[B, C]]): C = c.run(fa) match {
         case Right(c) => c
         case Left(bb) => loop(fn(bb))
       }
       loop(fn(b))
-    })
+    }
 
 }
 

diff --git a/core/src/main/scala/cats/data/Func.scala b/core/src/main/scala/cats/data/Func.scala
@@ -107,9 +107,9 @@ sealed abstract class AppFunc[F[_], A, B] extends Func[F, A, B] { self =>
 
   def compose[G[_], C](g: AppFunc[G, C, A]): AppFunc[Nested[G, F, *], C, B] = {
     implicit val gfApplicative: Applicative[Nested[G, F, *]] = Nested.catsDataApplicativeForNested[G, F](g.F, F)
-    Func.appFunc[Nested[G, F, *], C, B]({ (c: C) =>
+    Func.appFunc[Nested[G, F, *], C, B] { (c: C) =>
       Nested(g.F.map(g.run(c))(self.run))
-    })
+    }
   }
 
   def andThen[G[_], C](g: AppFunc[G, B, C]): AppFunc[Nested[F, G, *], A, C] =

diff --git a/core/src/main/scala/cats/data/Kleisli.scala b/core/src/main/scala/cats/data/Kleisli.scala
@@ -598,9 +598,9 @@ private[data] trait KleisliFlatMap[F[_], A] extends FlatMap[Kleisli[F, A, *]] wi
     fa.flatMap(f)
 
   def tailRecM[B, C](b: B)(f: B => Kleisli[F, A, Either[B, C]]): Kleisli[F, A, C] =
-    Kleisli[F, A, C]({ a =>
-      F.tailRecM(b) { f(_).run(a) }
-    })
+    Kleisli[F, A, C] { a =>
+      F.tailRecM(b)(f(_).run(a))
+    }
 }
 
 private[data] trait KleisliApplicative[F[_], A] extends Applicative[Kleisli[F, A, *]] with KleisliApply[F, A] {

diff --git a/core/src/main/scala/cats/data/WriterT.scala b/core/src/main/scala/cats/data/WriterT.scala
@@ -200,7 +200,7 @@ final case class WriterT[F[_], L, V](run: F[(L, V)]) {
    * }}}
    */
   def mapBoth[M, U](f: (L, V) => (M, U))(implicit functorF: Functor[F]): WriterT[F, M, U] =
-    WriterT { functorF.map(run)(f.tupled) }
+    WriterT(functorF.map(run)(f.tupled))
 
   /**
    * Example:

diff --git a/core/src/main/scala/cats/instances/either.scala b/core/src/main/scala/cats/instances/either.scala
@@ -37,6 +37,8 @@ trait EitherInstances extends cats.kernel.instances.EitherInstances {
   implicit def catsStdInstancesForEither[A]
     : MonadError[Either[A, *], A] with Traverse[Either[A, *]] with Align[Either[A, *]] =
     new MonadError[Either[A, *], A] with Traverse[Either[A, *]] with Align[Either[A, *]] {
+      override def unit: Either[A, Unit] = Either.unit
+
       def pure[B](b: B): Either[A, B] = Right(b)
 
       def flatMap[B, C](fa: Either[A, B])(f: B => Either[A, C]): Either[A, C] =

diff --git a/core/src/main/scala/cats/instances/map.scala b/core/src/main/scala/cats/instances/map.scala
@@ -28,9 +28,9 @@ trait MapInstances extends cats.kernel.instances.MapInstances {
         val gba: Eval[G[Map[K, B]]] = Always(G.pure(Map.empty))
         val gbb = Foldable
           .iterateRight(fa, gba) { (kv, lbuf) =>
-            G.map2Eval(f(kv._2), lbuf)({ (b, buf) =>
+            G.map2Eval(f(kv._2), lbuf) { (b, buf) =>
               buf + (kv._1 -> b)
-            })
+            }
           }
           .value
         G.map(gbb)(_.toMap)

diff --git a/core/src/main/scala/cats/instances/sortedMap.scala b/core/src/main/scala/cats/instances/sortedMap.scala
@@ -38,9 +38,9 @@ trait SortedMapInstances extends SortedMapInstances2 {
         val gba: Eval[G[SortedMap[K, B]]] = Always(G.pure(SortedMap.empty(Order[K].toOrdering)))
         Foldable
           .iterateRight(fa, gba) { (kv, lbuf) =>
-            G.map2Eval(f(kv._2), lbuf)({ (b, buf) =>
+            G.map2Eval(f(kv._2), lbuf) { (b, buf) =>
               buf + (kv._1 -> b)
-            })
+            }
           }
           .value
       }
@@ -186,9 +186,9 @@ private[instances] trait SortedMapInstancesBinCompat0 {
         val gba: Eval[G[SortedMap[K, B]]] = Always(G.pure(SortedMap.empty))
         Foldable
           .iterateRight(fa, gba) { (kv, lbuf) =>
-            G.map2Eval(f(kv._2), lbuf)({ (ob, buf) =>
+            G.map2Eval(f(kv._2), lbuf) { (ob, buf) =>
               ob.fold(buf)(b => buf + (kv._1 -> b))
-            })
+            }
           }
           .value
       }

diff --git a/core/src/main/scala/cats/syntax/either.scala b/core/src/main/scala/cats/syntax/either.scala
@@ -357,6 +357,9 @@ final class EitherObjectOps(private val either: Either.type) extends AnyVal { //
     case None    => left[A, B](ifNone)
     case Some(a) => right(a)
   }
+
+  /** Cached value of `Right(())` to avoid allocations for a common case. */
+  def unit[A]: Either[A, Unit] = EitherUtil.unit
 }
 
 final class LeftOps[A, B](private val left: Left[A, B]) extends AnyVal {
@@ -456,4 +459,6 @@ private[cats] object EitherUtil {
     right.asInstanceOf[Either[C, B]]
   def rightCast[A, B, C](left: Left[A, B]): Either[A, C] =
     left.asInstanceOf[Either[A, C]]
+
+  private[cats] val unit = Right(())
 }
diff --git a/core/src/main/scala/cats/syntax/monadError.scala b/core/src/main/scala/cats/syntax/monadError.scala
@@ -36,5 +36,7 @@ final class MonadErrorOps[F[_], E, A](private val fa: F[A]) extends AnyVal {
 
 final class MonadErrorRethrowOps[F[_], E, A](private val fea: F[Either[E, A]]) extends AnyVal {
   def rethrow(implicit F: MonadError[F, _ >: E]): F[A] =
-    F.flatMap(fea)(_.fold(F.raiseError, F.pure)) // dup from the type class impl, due to https://github.com/scala/bug/issues/11562. Once fixed should be able to replace with `F.rethrow(fea)`
+    F.flatMap(fea)(
+      _.fold(F.raiseError, F.pure)
+    ) // dup from the type class impl, due to https://github.com/scala/bug/issues/11562. Once fixed should be able to replace with `F.rethrow(fea)`
 }
diff --git a/free/src/test/scala/cats/free/CofreeSuite.scala b/free/src/test/scala/cats/free/CofreeSuite.scala
@@ -1,7 +1,9 @@
-package cats
-package free
+package cats.free
 
+import cats.{~>, Comonad, Eval, Id, Reducible, Traverse}
 import cats.data.{NonEmptyList, OptionT}
+import cats.instances.all._
+import cats.kernel.Eq
 import cats.laws.discipline.{ComonadTests, ReducibleTests, SerializableTests, TraverseTests}
 import cats.laws.discipline.SemigroupalTests.Isomorphisms
 import cats.syntax.list._

diff --git a/free/src/test/scala/cats/free/ContravariantCoyonedaSuite.scala b/free/src/test/scala/cats/free/ContravariantCoyonedaSuite.scala
@@ -1,10 +1,11 @@
-package cats
-package free
+package cats.free
 
+import cats.{~>, Contravariant}
 import cats.arrow.FunctionK
-import cats.tests.CatsSuite
+import cats.instances.all._
+import cats.kernel.Eq
 import cats.laws.discipline.{ContravariantTests, SerializableTests}
-
+import cats.tests.CatsSuite
 import org.scalacheck.{Arbitrary}
 
 class ContravariantCoyonedaSuite extends CatsSuite {

diff --git a/free/src/test/scala/cats/free/CoyonedaSuite.scala b/free/src/test/scala/cats/free/CoyonedaSuite.scala
@@ -1,10 +1,11 @@
-package cats
-package free
+package cats.free
 
-import cats.tests.CatsSuite
+import cats.Functor
 import cats.arrow.FunctionK
+import cats.instances.all._
+import cats.kernel.Eq
 import cats.laws.discipline.{FunctorTests, SerializableTests}
-
+import cats.tests.CatsSuite
 import org.scalacheck.Arbitrary
 
 class CoyonedaSuite extends CatsSuite {

diff --git a/free/src/test/scala/cats/free/FreeApplicativeSuite.scala b/free/src/test/scala/cats/free/FreeApplicativeSuite.scala
@@ -1,12 +1,14 @@
-package cats
-package free
+package cats.free
 
-import cats.tests.CatsSuite
+import cats.{~>, Applicative, Apply, Id}
 import cats.arrow.FunctionK
+import cats.data.State
+import cats.instances.all._
+import cats.kernel.Eq
 import cats.laws.discipline.{ApplicativeTests, SerializableTests}
 import cats.laws.discipline.SemigroupalTests.Isomorphisms
-import cats.data.State
-
+import cats.syntax.apply._
+import cats.tests.CatsSuite
 import org.scalacheck.{Arbitrary, Gen}
 
 class FreeApplicativeSuite extends CatsSuite {

diff --git a/free/src/test/scala/cats/free/FreeInvariantMonoidalSuite.scala b/free/src/test/scala/cats/free/FreeInvariantMonoidalSuite.scala
@@ -1,13 +1,17 @@
-package cats
-package tests
+package cats.free
 
+import cats.{Id, InvariantMonoidal}
 import cats.arrow.FunctionK
-import cats.free.FreeInvariantMonoidal
+import cats.kernel.Eq
+import cats.instances.all._
 import cats.laws.discipline.{InvariantMonoidalTests, MiniInt, SerializableTests}
 import cats.laws.discipline.arbitrary._
 import cats.laws.discipline.SemigroupalTests.Isomorphisms
-import org.scalacheck.{Arbitrary, Gen}
+import cats.syntax.invariant._
+import cats.syntax.semigroupal._
 import cats.tests.BinCodecInvariantMonoidalSuite._
+import cats.tests.CatsSuite
+import org.scalacheck.{Arbitrary, Gen}
 
 class FreeInvariantMonoidalSuite extends CatsSuite {
   implicit def freeInvariantMonoidalArbitrary[F[_], A](implicit F: Arbitrary[F[A]],

diff --git a/free/src/test/scala/cats/free/FreeSuite.scala b/free/src/test/scala/cats/free/FreeSuite.scala
@@ -1,15 +1,17 @@
-package cats
-package free
+package cats.free
 
+import cats.{:<:, Foldable, Functor, Id, Monad, Traverse}
 import cats.arrow.FunctionK
 import cats.data.EitherK
+import cats.instances.all._
+import cats.kernel.Eq
 import cats.laws.discipline.{DeferTests, FoldableTests, MonadTests, SerializableTests, TraverseTests}
 import cats.laws.discipline.arbitrary.catsLawsArbitraryForFn0
 import cats.laws.discipline.SemigroupalTests.Isomorphisms
+import cats.syntax.apply._
 import cats.tests.CatsSuite
-
 import org.scalacheck.{Arbitrary, Cogen, Gen}
-import Arbitrary.arbFunction1
+import org.scalacheck.Arbitrary.arbFunction1
 
 class FreeSuite extends CatsSuite {
   import FreeSuite._