Mixer bug for non-primitives

alphabet-soup/src/test/scala/io/typechecked/alphabetsoup/MixerSpec.scala

@@ -1,6 +1,7 @@
 package io.typechecked
 package alphabetsoup
 
+import io.typechecked.alphabetsoup.macros.Atomic
 import org.scalatest.FlatSpec
 import org.scalatest.Matchers
 import shapeless.::
@@ -36,6 +37,34 @@ class MixerSpec extends FlatSpec with Matchers {
     Mixer[A1, A1].mix(A1(5, "hello")) shouldBe A1(5, "hello")
   }
 
+  it should "select smaller type from larger for primitives" in {
+    implicitly[Mixer[(String, Int), Int]]
+    implicitly[Mixer[(String, Int), String]]
+  }
+
+  it should "select smaller type from larger for non-primitives" in {
+
+    @Atomic class A
+    @Atomic class B
+
+    pendingUntilFixed{
+      "implicitly[Mixer[(A, B), B]]" should compile
+    }
+
+    @Atomic trait C
+    @Atomic trait D
+
+    implicitly[Mixer[(C, D), D]]
+    implicitly[Mixer[(C, D), C]]
+
+    @Atomic case class E()
+    @Atomic case class F()
+
+    pendingUntilFixed{
+      "implicitly[Mixer[(E, F), F]]" should compile
+    }
+  }
+
   it should "not work on mis-matched simple types" in {
     illTyped("""Mixer[Int, String]""")
   }