Cross-build scalacheck module on scala 3

.github/workflows/ci.yml

@@ -83,7 +83,7 @@ jobs:
 
       - name: Test
         if: matrix.scala == '3'
-        run: sbt 'project ${{ matrix.project }}' '++ ${{ matrix.scala }}' shared/test test/test
+        run: sbt 'project ${{ matrix.project }}' '++ ${{ matrix.scala }}' shared/test test/test scalacheck/test
 
       - name: Check binary compatibility
         if: '!(matrix.scala == ''3'')'

build.sbt

@@ -46,7 +46,7 @@ val tensorflowMetadataVersion = "1.10.0"
 val tensorflowVersion = "0.5.0"
 
 // project
-ThisBuild / tlBaseVersion := "0.7"
+ThisBuild / tlBaseVersion := "0.8"
 ThisBuild / tlSonatypeUseLegacyHost := true
 ThisBuild / organization := "com.spotify"
 ThisBuild / organizationName := "Spotify AB"
@@ -110,7 +110,8 @@ val scala212 = "2.12.19"
 val scalaDefault = scala213
 val scala3Projects = List(
   "shared",
-  "test"
+  "test",
+  "scalacheck"
 )
 
 // github actions
@@ -267,7 +268,9 @@ val commonSettings = Seq(
         "-Yretain-trees",
         // tolerate some nested macro expansion
         "-Xmax-inlines",
-        "64"
+        "64",
+        // silence warnings. dotty doesn't have unused-imports category nor origin support yet
+        "-Wconf:msg=unused import:s"
       )
     case Some((2, 13)) =>
       Seq(
@@ -373,6 +376,7 @@ lazy val scalacheck = project
     commonSettings,
     moduleName := "magnolify-scalacheck",
     description := "Magnolia add-on for ScalaCheck",
+    crossScalaVersions := Seq(scala3, scala213, scala212),
     libraryDependencies += "org.scalacheck" %% "scalacheck" % scalacheckVersion % Provided
   )
 

docs/scalacheck.md

@@ -25,6 +25,6 @@ import org.scalacheck._
 case class Inner(int: Int, str: String)
 case class Outer(inner: Inner)
 
-val arb: Arbitrary[Outer] = ArbitraryDerivation[Outer]
-val cogen: Cogen[Outer] = CogenDerivation[Outer]
+val arb: Arbitrary[Outer] = Arbitrary.gen[Outer]
+val cogen: Cogen[Outer] = Cogen.gen[Outer]
 ```

scalacheck/src/main/scala-2/magnolify/scalacheck/ArbitraryDerivation.scala

@@ -0,0 +1,58 @@
+/*
+ * Copyright 2024 Spotify AB
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package magnolify.scalacheck
+
+import magnolia1.*
+import org.scalacheck.{Arbitrary, Gen}
+
+object ArbitraryDerivation {
+  type Typeclass[T] = Arbitrary[T]
+
+  private implicit val monadicGen: Monadic[Gen] = new Monadic[Gen] {
+    override def point[A](value: A): Gen[A] = Gen.const(value)
+    override def map[A, B](from: Gen[A])(fn: A => B): Gen[B] = from.map(fn)
+    override def flatMap[A, B](from: Gen[A])(fn: A => Gen[B]): Gen[B] = from.flatMap(fn)
+  }
+
+  def join[T](caseClass: CaseClass[Arbitrary, T]): Arbitrary[T] = Arbitrary {
+    caseClass.constructMonadic(_.typeclass.arbitrary)
+  }
+
+  def split[T](sealedTrait: SealedTrait[Arbitrary, T]): Arbitrary[T] = Arbitrary {
+    Gen.lzy {
+      Gen.sized { size =>
+        val subtypes = sealedTrait.subtypes
+        for {
+          i <-
+            if (size >= 0) {
+              // pick any subtype
+              Gen.choose(0, subtypes.size - 1)
+            } else {
+              // pick a fixed subtype to have a chance to stop recursion
+              Gen.const(subtypes.size + size)
+            }
+          subtypeGen <- Gen.resize(size - 1, subtypes(i).typeclass.arbitrary)
+        } yield subtypeGen
+      }
+    }
+  }
+
+  implicit def gen[T]: Arbitrary[T] = macro Magnolia.gen[T]
+
+  @deprecated("Use gen instead", "0.7.0")
+  def apply[T]: Arbitrary[T] = macro Magnolia.gen[T]
+}

scalacheck/src/main/scala/magnolify/scalacheck/semiauto/CogenDerivation.scala → scalacheck/src/main/scala-2/magnolify/scalacheck/CogenDerivation.scala

@@ -14,29 +14,29 @@
  * limitations under the License.
  */
 
-package magnolify.scalacheck.semiauto
+package magnolify.scalacheck
 
-import magnolia1._
+import magnolia1.*
 import org.scalacheck.Cogen
 
 object CogenDerivation {
   type Typeclass[T] = Cogen[T]
 
-  def join[T](caseClass: ReadOnlyCaseClass[Typeclass, T]): Typeclass[T] = Cogen { (seed, t) =>
-    caseClass.parameters.foldLeft(seed) { (seed, p) =>
+  def join[T](caseClass: CaseClass[Cogen, T]): Cogen[T] = Cogen { (seed, t) =>
+    caseClass.parameters.foldLeft(seed) { (s, p) =>
       // inject index to distinguish cases like `(Some(false), None)` and `(None, Some(0))`
-      val s = Cogen.cogenInt.perturb(seed, p.index)
-      p.typeclass.perturb(s, p.dereference(t))
+      p.typeclass.perturb(Cogen.perturb(s, p.index), p.dereference(t))
     }
   }
 
-  def split[T](sealedTrait: SealedTrait[Typeclass, T]): Typeclass[T] = Cogen { (seed, t: T) =>
+  def split[T](sealedTrait: SealedTrait[Cogen, T]): Cogen[T] = Cogen { (seed, t) =>
     sealedTrait.split(t) { sub =>
       // inject index to distinguish case objects instances
-      val s = Cogen.cogenInt.perturb(seed, sub.index)
-      sub.typeclass.perturb(s, sub.cast(t))
+      sub.typeclass.perturb(Cogen.perturb(seed, sub.index), sub.cast(t))
     }
   }
 
-  implicit def apply[T]: Typeclass[T] = macro Magnolia.gen[T]
+  implicit def gen[T]: Cogen[T] = macro Magnolia.gen[T]
+  @deprecated("Use gen instead", "0.7.0")
+  def apply[T]: Cogen[T] = macro Magnolia.gen[T]
 }

scalacheck/src/main/scala-2/magnolify/scalacheck/ScalacheckMacros.scala

@@ -0,0 +1,41 @@
+/*
+ * Copyright 2023 Spotify AB
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package magnolify.scalacheck
+
+import org.scalacheck.{Arbitrary, Cogen}
+
+import scala.reflect.macros.*
+object ScalaCheckMacros {
+  def derivationArbitraryMacro[T: c.WeakTypeTag](c: whitebox.Context): c.Tree = {
+    import c.universe._
+    val wtt = weakTypeTag[T]
+    q"""_root_.magnolify.scalacheck.ArbitraryDerivation.gen[$wtt]"""
+  }
+
+  def derivationCogenMacro[T: c.WeakTypeTag](c: whitebox.Context): c.Tree = {
+    import c.universe._
+    val wtt = weakTypeTag[T]
+    q"""_root_.magnolify.scalacheck.CogenDerivation.gen[$wtt]"""
+  }
+}
+
+trait AutoDerivations {
+  implicit def autoDerivationArbitrary[T]: Arbitrary[T] =
+    macro ScalaCheckMacros.derivationArbitraryMacro[T]
+  implicit def autoDerivationCogen[T]: Cogen[T] =
+    macro ScalaCheckMacros.derivationCogenMacro[T]
+}

scalacheck/src/main/scala-3/magnolify/scalacheck/ArbitraryDerivation.scala

@@ -0,0 +1,54 @@
+/*
+ * Copyright 2024 Spotify AB
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package magnolify.scalacheck
+
+import magnolia1.*
+import org.scalacheck.{Arbitrary, Gen}
+
+import scala.deriving.Mirror
+
+object ArbitraryDerivation extends Derivation[Arbitrary]:
+
+  private given Monadic[Gen] with
+    def point[A](value: A): Gen[A] = Gen.const(value)
+    def map[A, B](from: Gen[A])(fn: A => B): Gen[B] = from.map(fn)
+    def flatMap[A, B](from: Gen[A])(fn: A => Gen[B]): Gen[B] = from.flatMap(fn)
+
+  def join[T](caseClass: CaseClass[Arbitrary, T]): Arbitrary[T] = Arbitrary {
+    caseClass.constructMonadic(_.typeclass.arbitrary)
+  }
+
+  def split[T](sealedTrait: SealedTrait[Arbitrary, T]): Arbitrary[T] = Arbitrary {
+    Gen.lzy {
+      Gen.sized { size =>
+        val subtypes = sealedTrait.subtypes
+        for {
+          i <-
+            if (size >= 0) {
+              // pick any subtype
+              Gen.choose(0, subtypes.size - 1)
+            } else {
+              // pick a fixed subtype to have a chance to stop recursion
+              Gen.const(subtypes.size + size)
+            }
+          subtypeGen <- Gen.resize(size - 1, subtypes(i).typeclass.arbitrary)
+        } yield subtypeGen
+      }
+    }
+  }
+
+  inline def gen[T](using Mirror.Of[T]): Arbitrary[T] = derivedMirror[T]

scalacheck/src/main/scala-3/magnolify/scalacheck/CogenDerivation.scala

@@ -0,0 +1,40 @@
+/*
+ * Copyright 2023 Spotify AB
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package magnolify.scalacheck
+
+import magnolia1.*
+import org.scalacheck.Cogen
+
+import scala.deriving.Mirror
+
+object CogenDerivation extends Derivation[Cogen]:
+
+  def join[T](caseClass: CaseClass[Cogen, T]): Cogen[T] = Cogen[T] { (seed, t) =>
+    caseClass.params.foldLeft(seed) { (s, p) =>
+      // inject index to distinguish cases like `(Some(false), None)` and `(None, Some(0))`
+      p.typeclass.perturb(Cogen.perturb(s, p.index), p.deref(t))
+    }
+  }
+
+  def split[T](sealedTrait: SealedTrait[Cogen, T]): Cogen[T] = Cogen[T] { (seed, t) =>
+    sealedTrait.choose(t) { sub =>
+      // inject index to distinguish case objects instances
+      sub.typeclass.perturb(Cogen.perturb(seed, sub.subtype.index), sub.cast(t))
+    }
+  }
+
+  inline def gen[T](using Mirror.Of[T]): Cogen[T] = derivedMirror[T]

scalacheck/src/main/scala-3/magnolify/scalacheck/ScalacheckMacros.scala

@@ -0,0 +1,27 @@
+/*
+ * Copyright 2024 Spotify AB
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package magnolify.scalacheck
+
+import org.scalacheck.{Arbitrary, Cogen}
+
+import scala.deriving.Mirror
+
+trait AutoDerivations:
+  inline implicit def autoDerivationArbitrary[T](using Mirror.Of[T]): Arbitrary[T] =
+    ArbitraryDerivation.derivedMirror[T]
+  inline implicit def autoDerivationCogen[T](using Mirror.Of[T]): Cogen[T] =
+    CogenDerivation.derivedMirror[T]

scalacheck/src/main/scala/magnolify/scalacheck/auto/package.scala

@@ -16,23 +16,4 @@
 
 package magnolify.scalacheck
 
-import org.scalacheck._
-
-import scala.reflect.macros._
-
-package object auto {
-  def genArbitraryMacro[T: c.WeakTypeTag](c: whitebox.Context): c.Tree = {
-    import c.universe._
-    val wtt = weakTypeTag[T]
-    q"""_root_.magnolify.scalacheck.semiauto.ArbitraryDerivation.apply[$wtt]"""
-  }
-
-  def genCogenMacro[T: c.WeakTypeTag](c: whitebox.Context): c.Tree = {
-    import c.universe._
-    val wtt = weakTypeTag[T]
-    q"""_root_.magnolify.scalacheck.semiauto.CogenDerivation.apply[$wtt]"""
-  }
-
-  implicit def genArbitrary[T]: Arbitrary[T] = macro genArbitraryMacro[T]
-  implicit def genCogen[T]: Cogen[T] = macro genCogenMacro[T]
-}
+package object auto extends AutoDerivations