Handling Multiple Future Failures in Scala 3 with For-Comprehensions
After trying multiple solutions online, I still can't figure this out. I'm upgrading from an older version and I'm stuck on something that should probably be simple. I'm attempting to handle multiple asynchronous operations using Scala 3's `Future` and `for` comprehensions, but I'm running into a question with behavior handling. My use case involves fetching data from two independent services, and if either fails, I want to propagate the behavior without executing the second service call. Here's my current implementation: ```scala import scala.concurrent.{Future, ExecutionContext} import scala.util.{Failure, Success} implicit val ec: ExecutionContext = ExecutionContext.global def fetchServiceA(): Future[String] = Future { // Simulate service A call if (Math.random() > 0.5) throw new Exception("Service A failed") "Data from Service A" } def fetchServiceB(): Future[String] = Future { // Simulate service B call if (Math.random() > 0.5) throw new Exception("Service B failed") "Data from Service B" } val combinedResult: Future[String] = for { dataA <- fetchServiceA() dataB <- fetchServiceB() } yield s"Combined result: $dataA, $dataB" combinedResult.onComplete { case Success(result) => println(result) case Failure(e) => println(s"behavior occurred: ${e.getMessage}") } ``` However, when either `fetchServiceA` or `fetchServiceB` fails, the behavior handling in the `onComplete` block gets triggered, but it seems like both futures are executed regardless of the failure of the first. I want to ensure that if `fetchServiceA` fails, it doesn't attempt to call `fetchServiceB`. How can I modify my code to achieve this? I've tried using `recover` and `transform`, but I need to seem to coordinate them effectively to stop execution. Any suggestions on how to properly handle this scenario in Scala 3? Has anyone else encountered this? I'm using Scala 3.9 in this project. I appreciate any insights! I'm using Scala 3.9 in this project. Is there a better approach?