Merge pull request #4223 from armanbilge/fix/mainthread-runnable-failure

Report non-fatal `Runnable` failures on `MainThread` EC
typelevel · Jan 2, 2025 · d1369b7 · d1369b7
2 parents a49a028 + ddbb603
commit d1369b7
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Showing 3 changed files with 19 additions and 6 deletions.
diff --git a/core/jvm/src/main/scala/cats/effect/IOApp.scala b/core/jvm/src/main/scala/cats/effect/IOApp.scala
@@ -568,12 +568,7 @@ trait IOApp {
               r.run()
             } catch {
               case t if NonFatal(t) =>
-                if (isForked) {
-                  t.printStackTrace()
-                  System.exit(1)
-                } else {
-                  throw t
-                }
+                IOApp.this.reportFailure(t).unsafeRunAndForgetWithoutCallback()(runtime)
 
               case t: Throwable =>
                 t.printStackTrace()

diff --git a/ioapp-tests/src/test/scala/IOAppSpec.scala b/ioapp-tests/src/test/scala/IOAppSpec.scala
@@ -354,6 +354,11 @@ class IOAppSpec extends Specification {
         h.awaitStatus() mustEqual 0
       }
 
+      "use configurable reportFailure for runnables on MainThread" in {
+        val h = platform("MainThreadReportFailureRunnable", List.empty)
+        h.awaitStatus() mustEqual 0
+      }
+
       "warn on blocked threads" in {
         val h = platform("BlockedThreads", List.empty)
         h.awaitStatus()

diff --git a/tests/jvm/src/main/scala/catseffect/examplesplatform.scala b/tests/jvm/src/main/scala/catseffect/examplesplatform.scala
@@ -71,6 +71,19 @@ package examples {
 
   }
 
+  object MainThreadReportFailureRunnable extends IOApp {
+
+    val exitCode = new AtomicReference[ExitCode](ExitCode.Error)
+
+    override def reportFailure(err: Throwable): IO[Unit] =
+      IO(exitCode.set(ExitCode.Success))
+
+    def run(args: List[String]): IO[ExitCode] =
+      IO(MainThread.execute(() => throw new Exception)) *>
+        IO.sleep(1.second) *> IO(exitCode.get)
+
+  }
+
   object BlockedThreads extends IOApp.Simple {
 
     override protected def blockedThreadDetectionEnabled = true