add filter and filterNot to Pot

gemini-hlsw · Dec 11, 2023 · e0907bf · e0907bf
1 parent fe78a2d
commit e0907bf
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Showing 2 changed files with 18 additions and 6 deletions.
diff --git a/modules/core/shared/src/main/scala/crystal/Pot.scala b/modules/core/shared/src/main/scala/crystal/Pot.scala
@@ -66,6 +66,14 @@ sealed trait Pot[+A] {
     }
 
   def toOptionEither: Option[Either[Throwable, A]] = toOptionTry.map(_.toEither)
+
+  def filter(f: A => Boolean): Pot[A] =
+    this match {
+      case Pot.Ready(a) if !f(a) => Pot.pending
+      case _                     => this
+    }
+
+  def filterNot(f: A => Boolean): Pot[A] = filter(a => !f(a))
 }
 
 object Pot {

diff --git a/modules/tests/shared/src/test/scala/crystal/PotSpec.scala b/modules/tests/shared/src/test/scala/crystal/PotSpec.scala
@@ -144,11 +144,15 @@ class PotSpec extends DisciplineSuite {
     }
   }
 
-  // property("Ready(None).flatOpt === Pending") {
-  //   Pot.Ready(None).flatOpt == Pot.Pending
-  // }
+  property("Pot[Int].filter") {
+    forAll { (p: Pot[Int]) =>
+      p.filter(_ > 0) === p.flatMap(i => if (i > 0) Pot.Ready(i) else Pot.Pending)
+    }
+  }
 
-  // property("Pot[Option[Int]] (Pot.flatten): Ready(Some(a)).flatOpt === Ready(a)") {
-  //   forAll((i: Int) => Pot.Ready(Some(i)).flatOpt === Pot.Ready(i))
-  // }
+  property("Pot[Int].filterNot") {
+    forAll { (p: Pot[Int]) =>
+      p.filterNot(_ > 0) === p.flatMap(i => if (i <= 0) Pot.Ready(i) else Pot.Pending)
+    }
+  }
 }