One more flatMap test

lichess-org · Jul 9, 2023 · 133c52c · 133c52c
1 parent b72bd66
commit 133c52c
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Showing 2 changed files with 5 additions and 3 deletions.
diff --git a/src/main/scala/ByColor.scala b/src/main/scala/ByColor.scala
@@ -1,11 +1,9 @@
 package chess
 
-import cats.{ Applicative, Eq, Functor, Monoid }
+import cats.{ Applicative, Eq, Eval, Functor, Monoid, Traverse }
 import cats.syntax.all.*
 import scala.annotation.targetName
 import alleycats.Zero
-import cats.Traverse
-import cats.Eval
 
 case class ByColor[A](white: A, black: A):
 

diff --git a/src/test/scala/ByColorTest.scala b/src/test/scala/ByColorTest.scala
@@ -56,6 +56,10 @@ class ByColorTest extends ScalaCheckSuite:
     forAll: (bc: ByColor[Option[Int]]) =>
       bc.flatten == bc.flatMap(identity)
 
+  test("flatMap == all.flatMap"):
+    forAll: (bc: ByColor[Int], f: Int => Option[String]) =>
+      bc.flatMap(f) == bc.all.flatMap(f(_))
+
   test("fold"):
     forAll: (bc: ByColor[Int], init: String, f: (String, Int) => String) =>
       bc.fold(init)(f) == bc.all.foldLeft(init)(f)