Add Result.toOutcome (#91)

Author: Synesso

CHANGELOG.md

@@ -5,6 +5,7 @@
 ### Added
 * Adds `Result<T>.unit(): Result<Unit>` as alias for `.map { }` (Jem Mawson)
 * Adds `Result<T>.tap` and `Result<T>.flatTap` (Jem Mawson)
+* Adds `Result<T>.toOutcome` (Jem Mawson)
 
 ## [0.5.5] - 2024-06-20
 

lib/api/lib.api

@@ -60,6 +60,7 @@ public final class app/cash/quiver/OutcomeKt {
 	public static final fun tapFailure (Lapp/cash/quiver/Outcome;Lkotlin/jvm/functions/Function1;)Lapp/cash/quiver/Outcome;
 	public static final fun toOutcome (Larrow/core/Either;)Lapp/cash/quiver/Outcome;
 	public static final fun toOutcome (Larrow/core/Option;)Lapp/cash/quiver/Outcome;
+	public static final fun toOutcome (Ljava/lang/Object;)Lapp/cash/quiver/Outcome;
 	public static final fun traverse (Lapp/cash/quiver/Outcome;Lkotlin/jvm/functions/Function1;)Larrow/core/Either;
 	public static final fun traverse (Lapp/cash/quiver/Outcome;Lkotlin/jvm/functions/Function1;)Larrow/core/Option;
 	public static final fun traverse (Lapp/cash/quiver/Outcome;Lkotlin/jvm/functions/Function1;)Larrow/core/Validated;

lib/src/main/kotlin/app/cash/quiver/Outcome.kt

@@ -217,6 +217,11 @@ fun <E, A> Either<E, Option<A>>.toOutcome(): Outcome<E, A> = when (this) {
 
 fun <E, A> Either<E, A>.asOutcome(): Outcome<E, A> = this.map(::Some).toOutcome()
 
+fun <A> Result<A>.toOutcome(): Outcome<Throwable, A> = fold(
+  onSuccess = { Present(it) },
+  onFailure = { Failure(it) }
+)
+
 fun <A> Option<A>.toOutcome(): Outcome<Nothing, A> = this.right().toOutcome()
 
 inline fun <A> Outcome<Throwable, A>.orThrow(onAbsent: () -> Throwable): A = when (this) {

lib/src/test/kotlin/app/cash/quiver/OutcomeTest.kt

@@ -17,6 +17,7 @@ import arrow.core.right
 import arrow.core.some
 import arrow.core.valid
 import app.cash.quiver.continuations.outcome
+import app.cash.quiver.extensions.success
 import io.kotest.assertions.arrow.core.shouldBeInvalid
 import io.kotest.assertions.arrow.core.shouldBeLeft
 import io.kotest.assertions.arrow.core.shouldBeNone
@@ -190,6 +191,12 @@ class OutcomeTest : StringSpec({
     }.shouldBeAbsent()
   }
 
+  "Lift Result<A> into Outcome" {
+    val e = RuntimeException("hey")
+    Result.success(1).toOutcome().shouldBePresent().shouldBe(1)
+    Result.failure<Int>(e).toOutcome().shouldBeFailure().shouldBe(e)
+  }
+
   "Lift Either<E,A> into Outcome" {
     1.right().asOutcome().shouldBePresent().shouldBe(1)
     "bad".left().asOutcome().shouldBeFailure().shouldBe("bad")