Implement noneOrFail zio#4841

.bsp/sbt.json

@@ -0,0 +1 @@
+{"name":"sbt","version":"1.4.9","bspVersion":"2.0.0-M5","languages":["scala"],"argv":["/Users/michel/.sdkman/candidates/java/11.0.10.hs-adpt/bin/java","-Xms100m","-Xmx100m","-classpath","/Users/michel/Library/Application Support/JetBrains/Toolbox/apps/IDEA-C/ch-0/203.7148.57/IntelliJ IDEA CE.app.plugins/Scala/launcher/sbt-launch.jar","xsbt.boot.Boot","-bsp"]}

core-tests/shared/src/test/scala/zio/ZIOSpec.scala

@@ -1303,6 +1303,24 @@ object ZIOSpec extends ZIOBaseSpec {
         assertM(ZIO.succeed(false).negate)(equalTo(true))
       }
     ),
+    suite("noneOrFail")(
+      testM("on None succeeds with Unit") {
+        val option: Option[String]       = None
+        val adaptError: String => String = identity
+        for {
+          value <- ZIO.noneOrFail(option, adaptError)
+        } yield {
+          assert(value)(equalTo(()))
+        }
+      },
+      testM("on Some fails") {
+        for {
+          value <- ZIO.noneOrFail(Some("value"), (v: String) => v + v).catchAll(e => ZIO.succeed(e))
+        } yield {
+          assert(value)(equalTo("valuevalue"))
+        }
+      } @@ zioTag(errors)
+    ),
     suite("once")(
       testM("returns an effect that will only be executed once") {
         for {
@@ -2080,7 +2098,12 @@ object ZIOSpec extends ZIOBaseSpec {
       testM("fail ensuring") {
         var finalized = false
 
-        val io = Task.fail(ExampleError).ensuring(IO.effectTotal { finalized = true; () })
+        val io = Task
+          .fail(ExampleError)
+          .ensuring(IO.effectTotal {
+            finalized = true;
+            ()
+          })
 
         for {
           a1 <- assertM(io.run)(fails(equalTo(ExampleError)))

core/shared/src/main/scala/zio/IO.scala

@@ -730,6 +730,12 @@ object IO {
    */
   val none: UIO[Option[Nothing]] = ZIO.none
 
+  /**
+   * @see See [[zio.ZIO.noneOrFail()]]
+   */
+  def noneOrFail[E, O](o: Option[O], f: O => E): IO[E, Unit] =
+    ZIO.noneOrFail(o, f)
+
   /**
    *  @see See [[zio.ZIO.not]]
    */

core/shared/src/main/scala/zio/ZIO.scala

@@ -3649,6 +3649,14 @@ object ZIO extends ZIOCompanionPlatformSpecific {
    */
   val none: UIO[Option[Nothing]] = succeedNow(None)
 
+  /**
+   * Lifts an Option into a IO.
+   * If the option is empty it succeeds with Unit.
+   * If the option is defined it fails with an error adapted with f.
+   */
+  def noneOrFail[E, O](o: Option[O], f: O => E): IO[E, Unit] =
+    getOrFailUnit(o).flip.mapError(f)
+
   /**
    * Feeds elements of type `A` to a function `f` that returns an effect.
    * Collects all successes and failures in a tupled fashion.