Fix a build for Scala 2.12

Author: rtar

.scalafmt.conf

@@ -1,2 +1,8 @@
 version = "3.8.6"
-runner.dialect = scala213
+runner.dialect = scala213
+
+fileOverride {
+  "glob:**/src/main/scala-3/**" {
+    runner.dialect = scala3
+  }
+}

build.sbt

@@ -1,23 +1,21 @@
 import Dependencies._
 
 name := "random"
-
 organization := "com.evolution"
-
 homepage := Some(url("https://github.com/evolution-gaming/random"))
-
 startYear := Some(2019)
-
 organizationName := "Evolution"
-
 organizationHomepage := Some(url("https://evolution.com"))
 
 scalaVersion := crossScalaVersions.value.head
-
 crossScalaVersions := Seq("2.13.11", "2.12.18", "3.3.5")
-
 versionPolicyIntention := Compatibility.BinaryCompatible
 
+scalacOptions += {
+  if (scalaVersion.value startsWith "2.12") "-Ywarn-unused-import"
+  else "-Wunused:imports"
+}
+
 Compile / unmanagedSourceDirectories += {
   if (scalaVersion.value startsWith "2")
     sourceDirectory.value / "main" / "scala-2"

src/main/scala-3/com/evolutiongaming/random/Random.scala

@@ -18,7 +18,7 @@ object Random {
 
   def apply[F[_]](using F: Random[F]): Random[F] = F
 
-  extension [F[_]](self: Random[F]){
+  extension [F[_]](self: Random[F]) {
     def mapK[G[_]](f: F ~> G): Random[G] = new Random[G] {
       def int = f(self.int)
       def long = f(self.long)
@@ -27,7 +27,6 @@ object Random {
     }
   }
 
-
   type SeedT[A] = cats.data.StateT[Id, Seed, A]
 
   object SeedT {
@@ -41,7 +40,7 @@ object Random {
       def next(bits: Int): SeedT[Int] = {
         SeedT { seed =>
           val r = (seed >>> (48 - bits)).toInt
-          val s1 = (seed * 0x5DEECE66DL + 0xBL) & ((1L << 48) - 1)
+          val s1 = (seed * 0x5deece66dL + 0xbL) & ((1L << 48) - 1)
           (s1, r)
         }
       }
@@ -53,36 +52,32 @@ object Random {
         def long = {
           for
             a0 <- next(32)
-            a1  = a0.toLong << 32
+            a1 = a0.toLong << 32
             a2 <- next(32)
-          yield
-            a1 + a2
+          yield a1 + a2
         }
 
         def float = {
-          for
-            a <- next(24)
-          yield
-            a / floatUnit
+          for a <- next(24)
+          yield a / floatUnit
         }
 
         def double = {
           for
             a0 <- next(26)
-            a1  = a0.toLong << 27
+            a1 = a0.toLong << 27
             a2 <- next(27)
-          yield
-            (a1 + a2) * doubleUnit
+          yield (a1 + a2) * doubleUnit
         }
       }
     }
 
-
-    def apply[A](f: Seed => (Seed, A)): SeedT[A] = cats.data.StateT[Id, Seed, A] { seed => f(seed) }
+    def apply[A](f: Seed => (Seed, A)): SeedT[A] =
+      cats.data.StateT[Id, Seed, A] { seed => f(seed) }
   }
 
-
-  final case class State(seed: Seed, random: Random[SeedT] = SeedT.Random) extends Random[State.Type] {
+  final case class State(seed: Seed, random: Random[SeedT] = SeedT.Random)
+      extends Random[State.Type] {
 
     private def apply[A](stateT: SeedT[A]) = {
       val (seed1, a) = stateT.run(seed)
@@ -99,11 +94,13 @@ object Random {
 
     type Type[A] = (State, A)
 
-    def fromClock[F[_]: Clock: FlatMap](random: Random[SeedT] = SeedT.Random): F[State] = {
-      for
-        nanos <- Clock[F].nanos
+    def fromClock[F[_]: Clock: FlatMap](
+        random: Random[SeedT] = SeedT.Random
+    ): F[State] = {
+      for nanos <- Clock[F].nanos
       yield
-        val seed = (nanos ^ 3447679086515839964L ^ 0x5DEECE66DL) & ((1L << 48) - 1)
+        val seed =
+          (nanos ^ 3447679086515839964L ^ 0x5deece66dL) & ((1L << 48) - 1)
         apply(seed, random)
     }
   }