Add Output.when helper method (#439)

fixes #435
VirtusLab · Apr 9, 2024 · f4ba7cc · f4ba7cc
1 parent 94ba35f
commit f4ba7cc
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diff --git a/core/src/main/scala/besom/internal/Output.scala b/core/src/main/scala/besom/internal/Output.scala
@@ -80,6 +80,10 @@ trait OutputFactory:
   )(using BuildFrom[CC[Output[B]], B, To], Context): Output[To] = sequence(coll.map(f).asInstanceOf[CC[Output[B]]])
 
   def fail(t: Throwable)(using Context): Output[Nothing] = Output.fail(t)
+
+  def when[A: Typeable](cond: => Input.Optional[Boolean])(a: => Input.Optional[A])(using ctx: Context): Output[Option[A]] =
+    Output.when(cond)(a)
+
 end OutputFactory
 
 trait OutputExtensionsFactory:
@@ -188,4 +192,24 @@ object Output:
   def secret[A](value: A)(using ctx: Context): Output[A] =
     new Output[A](ctx.registerTask(Result.pure(OutputData(value, Set.empty, isSecret = true))))
 
+  def when[A: Typeable](cond: => Input.Optional[Boolean])(
+    a: => Input.Optional[A]
+  )(using ctx: Context): Output[Option[A]] =
+    val p: Output[Boolean] = cond.asOptionOutput(isSecret = false).flatMap {
+      case None             => Output(false)
+      case Some(b: Boolean) => Output(b)
+    }
+
+    def f(c: Boolean): Output[Option[A]] =
+      a.asOptionOutput(isSecret = false) match
+        case o: Output[A | Option[A]] if c =>
+          o.flatMap {
+            case None       => Output(None)
+            case Some(v: A) => Output(Some(v))
+            case a: A       => Output(Some(a))
+          }
+        case _ => Output(None) // return None if condition is false
+
+    p.flatMap(f)
+  end when
 end Output
diff --git a/core/src/test/scala/besom/internal/OutputTest.scala b/core/src/test/scala/besom/internal/OutputTest.scala
@@ -226,4 +226,35 @@ class OutputTest extends munit.FunSuite:
     Context().waitForAllTasks.unsafeRunSync()
   }
 
+  Vector(
+    (true, "value", Some("value")),
+    (false, "value", None)
+  ).foreach { (cond, value, expected) =>
+    given Context = DummyContext().unsafeRunSync()
+    for
+      optCond <- Vector(true, false)
+      outCond <- Vector(true, false)
+      optVal  <- Vector(true, false)
+      outVal  <- Vector(true, false)
+    do
+      val c: Boolean | Option[Boolean] | Output[Boolean] | Output[Option[Boolean]] = (outCond, optCond) match
+        case (true, true)   => Output(Option(cond))
+        case (true, false)  => Output(cond)
+        case (false, true)  => Some(cond)
+        case (false, false) => cond
+
+      val v: String | Option[String] | Output[String] | Output[Option[String]] = (outVal, optVal) match
+        case (true, true)   => Output(Option(value))
+        case (true, false)  => Output(value)
+        case (false, true)  => Some(value)
+        case (false, false) => value
+
+      test(s"when ${cond} then ${value} (optCond: ${optCond}, outCond: ${outCond}, valOpt: ${optVal}, valOut: ${outVal})") {
+        val result = Output.when(c)(v)
+        assertEquals(result.getData.unsafeRunSync(), OutputData(expected))
+      }
+
+    Context().waitForAllTasks.unsafeRunSync()
+  }
+
 end OutputTest