Merge pull request #170 from fthomas/topic/EqualArbitrary

Add Arbitrary instance for Equal

contrib/scalacheck/shared/src/main/scala/eu/timepit/refined/scalacheck/generic.scala

@@ -0,0 +1,17 @@
+package eu.timepit.refined
+package scalacheck
+
+import eu.timepit.refined.api.RefType
+import eu.timepit.refined.generic.Equal
+import org.scalacheck.{ Arbitrary, Gen }
+import shapeless.Witness
+
+/** Module that provides `Arbitrary` instances for generic predicates. */
+object generic {
+
+  implicit def equalArbitrary[F[_, _]: RefType, T, U <: T](
+    implicit
+    wu: Witness.Aux[U]
+  ): Arbitrary[F[T, Equal[U]]] =
+    arbitraryRefType(Gen.const(wu.value))
+}

contrib/scalacheck/shared/src/main/scala/eu/timepit/refined/scalacheck/numeric.scala

@@ -9,6 +9,10 @@ import org.scalacheck.Gen.Choose
 import shapeless.{ Nat, Witness }
 import shapeless.ops.nat.ToInt
 
+/**
+ * Module that provides `Arbitrary` instances and generators for
+ * numeric predicates.
+ */
 object numeric {
 
   /**

contrib/scalacheck/shared/src/test/scala/eu/timepit/refined/scalacheck/GenericArbitrarySpec.scala

@@ -0,0 +1,13 @@
+package eu.timepit.refined
+package scalacheck
+
+import eu.timepit.refined.api.Refined
+import eu.timepit.refined.generic.Equal
+import eu.timepit.refined.scalacheck.generic._
+import org.scalacheck.Properties
+
+class GenericArbitrarySpec extends Properties("GenericArbitrary") {
+
+  property("Equal") =
+    checkArbitraryRefType[Refined, Int, Equal[W.`100`.T]]
+}

notes/0.4.1.markdown

@@ -14,6 +14,7 @@
   val y: Int Refined Eval[W.`"(x: Int) => x > 0"`.T] = 1
   ```
   ([#153])
+* Add `Arbitrary` instance for `Equal`. ([#170])
 
 ### Updates
 
@@ -24,3 +25,4 @@
 [#155]: https://github.com/fthomas/refined/pull/155
 [#160]: https://github.com/fthomas/refined/pull/160
 [#165]: https://github.com/fthomas/refined/pull/165
+[#170]: https://github.com/fthomas/refined/pull/170