support generic sequence to be order insenstive.

typelevel · Sep 6, 2017 · 98b2e50 · 98b2e50
1 parent 5dd5d71
commit 98b2e50
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Showing 2 changed files with 15 additions and 5 deletions.
diff --git a/core/src/main/scala/cats/sequence/sequence.scala b/core/src/main/scala/cats/sequence/sequence.scala
@@ -6,8 +6,8 @@
 package cats.sequence
 
 import shapeless._
-import cats.{Functor, Apply}
-import shapeless.ops.hlist.ZipWithKeys
+import cats.{Apply, Functor}
+import shapeless.ops.hlist.{Align, ZipWithKeys}
 import shapeless.ops.record.{Keys, Values}
 
 import scala.annotation.implicitNotFound
@@ -95,18 +95,19 @@ object GenericSequencer extends MkGenericSequencer {
 
 trait MkGenericSequencer {
 
-  implicit def mkGenericSequencer[L <: HList, T, SOut <: HList, FOut, F[_]]
+  implicit def mkGenericSequencer[L <: HList, T, SOut <: HList, FOut, LOut <: HList, F[_]]
   ( implicit
     rs: RecordSequencer.Aux[L, FOut],
-    gen: LabelledGeneric.Aux[T, SOut],
+    gen: LabelledGeneric.Aux[T, LOut],
     eqv: FOut =:= F[SOut],
+    align: Align[SOut, LOut],
     F: Functor[F]
   ): GenericSequencer.Aux[L, T, F[T]] =
     new GenericSequencer[L, T] {
       type Out = F[T]
 
       def apply(in: L): Out = {
-        F.map(rs(in))(gen.from)
+        F.map(rs(in))(l => gen.from(l.align))
       }
     }
 }

diff --git a/core/src/test/scala/cats/sequence/sequence.scala b/core/src/test/scala/cats/sequence/sequence.scala
@@ -118,6 +118,15 @@ class SequenceTests extends KittensSuite {
     }
   })
 
+  test("sequence gen with different sort")(check {
+    forAll { (x: Option[Int], y: Option[String], z: Option[Float]) =>
+      val myGen = sequenceGeneric[MyCase]
+      val expected = (x, y, z) mapN MyCase.apply
+
+      myGen(b = y, a = x, c = z) == expected
+    }
+  })
+
   test("sequence gen for Either")(check {
     forAll { (x: Either[String, Int], y: Either[String, String], z: Either[String, Float]) =>
       val myGen = sequenceGeneric[MyCase]