From 46755dbba7f6210a87b23f10a4c935a7b377cd1c Mon Sep 17 00:00:00 2001
From: Jason LeBrun <jibbl@google.com>
Date: Mon, 30 Nov 2020 17:51:29 -0800
Subject: [PATCH] Propagate exception from OperationQueue.enqueueAndWait

PiperOrigin-RevId: 344924468
---
 java/arcs/core/storage/util/OperationQueue.kt      |  6 +++++-
 javatests/arcs/core/storage/util/BUILD             |  5 +----
 .../arcs/core/storage/util/SimpleQueueTest.kt      | 14 ++++++++++++++
 3 files changed, 20 insertions(+), 5 deletions(-)

diff --git a/java/arcs/core/storage/util/OperationQueue.kt b/java/arcs/core/storage/util/OperationQueue.kt
index 8bc1abc4274..680e6c20494 100644
--- a/java/arcs/core/storage/util/OperationQueue.kt
+++ b/java/arcs/core/storage/util/OperationQueue.kt
@@ -27,7 +27,11 @@ interface OperationQueue {
   suspend fun <T> enqueueAndWait(block: suspend () -> T): T {
     val result = CompletableDeferred<T>()
     enqueue {
-      result.complete(block())
+      try {
+        result.complete(block())
+      } catch (t: Throwable) {
+        result.completeExceptionally(t)
+      }
     }
     return result.await()
   }
diff --git a/javatests/arcs/core/storage/util/BUILD b/javatests/arcs/core/storage/util/BUILD
index bc9e4e8717a..1cf499b43fb 100644
--- a/javatests/arcs/core/storage/util/BUILD
+++ b/javatests/arcs/core/storage/util/BUILD
@@ -14,11 +14,8 @@ arcs_kt_jvm_test_suite(
         "//java/arcs/core/common",
         "//java/arcs/core/crdt",
         "//java/arcs/core/storage:proxy",
-        "//java/arcs/core/storage:reference",
-        "//java/arcs/core/storage:storage_key",
-        "//java/arcs/core/storage/keys",
-        "//java/arcs/core/storage/referencemode",
         "//java/arcs/core/storage/util",
+        "//java/arcs/core/testutil",
         "//third_party/java/junit:junit-android",
         "//third_party/java/truth:truth-android",
         "//third_party/kotlin/kotlinx_atomicfu",
diff --git a/javatests/arcs/core/storage/util/SimpleQueueTest.kt b/javatests/arcs/core/storage/util/SimpleQueueTest.kt
index e8254d0fcb2..49b53225ce8 100644
--- a/javatests/arcs/core/storage/util/SimpleQueueTest.kt
+++ b/javatests/arcs/core/storage/util/SimpleQueueTest.kt
@@ -1,5 +1,6 @@
 package arcs.core.storage.util
 
+import arcs.core.testutil.assertSuspendingThrows
 import com.google.common.truth.Truth.assertThat
 import kotlinx.atomicfu.atomic
 import kotlinx.coroutines.CompletableDeferred
@@ -33,6 +34,19 @@ class SimpleQueueTest {
     assertThat(ran).isTrue()
   }
 
+  @Test
+  fun enqueueAndWait_propagatesException() = runBlockingTest {
+    val queue = SimpleQueue()
+    class FakeException : Exception("test dummy")
+    val dummyException = FakeException()
+
+    val receivedException = assertSuspendingThrows(FakeException::class) {
+      queue.enqueueAndWait { throw dummyException }
+    }
+    // Strangely, the returned exception seems to be wrapped in itself... is this a Kotlin bug?
+    assertThat(receivedException.cause).isEqualTo(dummyException)
+  }
+
   @Test
   fun onEmptyIsCalled() = runBlockingTest {
     val deferred = CompletableDeferred<Unit>()