Add other exceptions from race as suppressed (#100)

Author: adamw

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

@@ -37,7 +37,14 @@ 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 failures.headOption.getOrElse(throw new NoSuchElementException).fold(em.pureError, throw _)
+      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)
+          case Right(e) =>
+            otherExceptions.foreach(ee => if e != ee then e.addSuppressed(ee))
+            throw e
       else
         result.take() match
           case Success(v) =>

core/src/test/scala/ox/RaceTest.scala

@@ -113,6 +113,24 @@ class RaceTest extends AnyFlatSpec with Matchers {
     end - start should be < 1000L
   }
 
+  it should "add other exceptions as suppressed" in {
+    try
+      race(
+        throw new RuntimeException("boom1!"), {
+          Thread.sleep(200)
+          throw new RuntimeException("boom2!")
+        }, {
+          Thread.sleep(200)
+          throw new RuntimeException("boom3!")
+        }
+      )
+      fail("Race should throw")
+    catch
+      case e: Exception =>
+        e.getMessage shouldBe "boom1!"
+        e.getSuppressed.map(_.getMessage).toSet shouldBe Set("boom2!", "boom3!")
+  }
+
   "raceEither" should "return the first successful computation to complete" in {
     val trail = Trail()
     val start = System.currentTimeMillis()