Make ambiguity test better

typelevel · Jun 29, 2017 · 87c9bda · 87c9bda
1 parent ed8c873
commit 87c9bda
Showing 1 changed file with 12 additions and 0 deletions.
diff --git a/tests/src/test/scala/cats/tests/OrderTests.scala b/tests/src/test/scala/cats/tests/OrderTests.scala
@@ -17,4 +17,16 @@ class OrderTests extends FunSuite {
     Invariant[Order]
     Contravariant[Order]
   }
+
+  // ambiguity test:
+  // the Ordering instance from the Order instance should be trumped
+  // by the one provided in the Ordering companion object
+  {
+    import cats.instances.all._
+    Ordering[String]
+    class C
+    implicit val ording: Ordering[C] = (_: C, _: C) => 0
+    implicit val ord: Order[C] = Order.allEqual
+    Ordering[C]
+  }
 }