Add possiblity to add suppressed application errors to ErrorMode (#101)

Author: adamw

core/src/main/scala/ox/ErrorMode.scala

@@ -32,7 +32,12 @@ trait ErrorMode[E, F[_]] {
   /** Adds a suppressed exception to the value being represented by `error`. This is only called if `isError(error)` returns `true`. By
     * default, the suppressed exception is discarded and the original value is returned.
     */
-  def addSuppressed[T](error: F[T], e: Throwable): F[T] = error
+  def addSuppressedException[T](error: F[T], e: Throwable): F[T] = error
+
+  /** Adds a suppressed application error to the value being represented by `error`. This is only called if `isError(error)` returns `true`.
+    * By default, the suppressed application error is discarded and the original value is returned.
+    */
+  def addSuppressedError[T](error: F[T], e: E): F[T] = error
 }
 
 /** An error mode which doesn't allow reporting application errors.
@@ -67,3 +72,7 @@ class UnionMode[E: ClassTag] extends ErrorMode[E, [T] =>> E | T] {
   override def pure[T](t: T): E | T = t
   override def pureError[T](e: E): E | T = e
 }
+
+//
+
+case class SecondaryApplicationError[E](e: E) extends Throwable("Secondary application error reported")

core/src/main/scala/ox/race.scala

@@ -38,12 +38,17 @@ def race[E, F[_], T](em: ErrorMode[E, F])(fs: Seq[() => F[T]]): F[T] =
     @tailrec
     def takeUntilSuccess(failures: Vector[Either[E, Throwable]], left: Int): F[T] =
       if left == 0 then
-        val otherExceptions = failures.tail.collect { case Right(e) => e }
         failures.headOption.getOrElse(throw new NoSuchElementException) match
           case Left(appError) =>
-            otherExceptions.foldLeft(em.pureError(appError))(em.addSuppressed)
+            failures.tail.foldLeft(em.pureError(appError)) {
+              case (acc, Left(e))  => em.addSuppressedError(acc, e)
+              case (acc, Right(e)) => em.addSuppressedException(acc, e)
+            }
           case Right(e) =>
-            otherExceptions.foreach(ee => if e != ee then e.addSuppressed(ee))
+            failures.tail.foreach {
+              case Left(ee)  => e.addSuppressed(SecondaryApplicationError(ee))
+              case Right(ee) => if e != ee then e.addSuppressed(ee)
+            }
             throw e
       else
         result.take() match

core/src/main/scala/ox/supervised.scala

@@ -54,12 +54,12 @@ def supervisedError[E, F[_], T](em: ErrorMode[E, F])(f: OxError[E, F] ?=> F[T]):
     // all forks are guaranteed to have finished; some might have ended up throwing exceptions (InterruptedException or
     // others), but if the scope ended because of an application error, only that result will be returned, hence we have
     // to add the other exceptions as suppressed
-    if em.isError(scopeResult) then s.addExceptionsAsSuppressed(scopeResult, em) else scopeResult
+    if em.isError(scopeResult) then s.addSuppressedErrors(scopeResult, em) else scopeResult
   catch
     case e: Throwable =>
       // all forks are guaranteed to have finished: some might have ended up throwing exceptions (InterruptedException or
       // others), but only the first one is propagated below. That's why we add all the other exceptions as suppressed.
-      s.addOtherExceptionsAsSuppressedTo(e)
+      s.addSuppressedErrors(e)
       throw e
 
 private[ox] sealed trait Supervisor[-E]:
@@ -79,6 +79,7 @@ private[ox] class DefaultSupervisor[E] extends Supervisor[E]:
   // the result might be completed with: a success marker, an app error, or an exception
   private val result: CompletableFuture[ErrorModeSupervisorResult | E] = new CompletableFuture()
   private val otherExceptions: java.util.Set[Throwable] = ConcurrentHashMap.newKeySet()
+  private val otherErrors: java.util.Set[E] = ConcurrentHashMap.newKeySet()
 
   override def forkStarts(): Unit = running.incrementAndGet()
 
@@ -88,7 +89,7 @@ private[ox] class DefaultSupervisor[E] extends Supervisor[E]:
 
   override def forkException(e: Throwable): Unit = if !result.completeExceptionally(e) then otherExceptions.add(e)
 
-  override def forkAppError(e: E): Unit = if !result.complete(e) then otherExceptions.add(SecondaryApplicationError(e))
+  override def forkAppError(e: E): Unit = if !result.complete(e) then otherErrors.add(e)
 
   /** Wait until the count of all supervised, user forks that are running reaches 0, or until any supervised fork fails with an exception.
     *
@@ -98,16 +99,16 @@ private[ox] class DefaultSupervisor[E] extends Supervisor[E]:
     */
   def join(): ErrorModeSupervisorResult | E = unwrapExecutionException(result.get())
 
-  def addOtherExceptionsAsSuppressedTo(e: Throwable): Throwable =
+  def addSuppressedErrors(e: Throwable): Throwable =
     otherExceptions.forEach(e2 => if e != e2 then e.addSuppressed(e2))
+    otherErrors.forEach(e2 => e.addSuppressed(SecondaryApplicationError(e2)))
     e
 
-  def addExceptionsAsSuppressed[F[_], T](r: F[T], errorMode: ErrorMode[E, F]): F[T] =
+  def addSuppressedErrors[F[_], T](r: F[T], errorMode: ErrorMode[E, F]): F[T] =
     var result = r
-    otherExceptions.forEach(e => result = errorMode.addSuppressed(result, e))
+    otherExceptions.forEach(e => result = errorMode.addSuppressedException(result, e))
+    otherErrors.forEach(e => result = errorMode.addSuppressedError(result, e))
     result
 
 private[ox] enum ErrorModeSupervisorResult:
   case Success
-
-case class SecondaryApplicationError[E](e: E) extends Throwable("Secondary application error reported to the supervisor")