From b6b0b4000d897d3ff86600cd8ea0707067193377 Mon Sep 17 00:00:00 2001
From: Artem Perepelitsa <perepelartem@gmail.com>
Date: Sat, 16 Oct 2021 11:55:30 +0300
Subject: [PATCH 1/2] Add unobserved task exception publishing if an exception
 inside ExceptionResultSource is never thrown

---
 .../UniTask/Runtime/UniTask.Factory.cs        | 33 +++++++++++++++++++
 1 file changed, 33 insertions(+)

diff --git a/src/UniTask/Assets/Plugins/UniTask/Runtime/UniTask.Factory.cs b/src/UniTask/Assets/Plugins/UniTask/Runtime/UniTask.Factory.cs
index c56cb03..2f6a6a9 100644
--- a/src/UniTask/Assets/Plugins/UniTask/Runtime/UniTask.Factory.cs
+++ b/src/UniTask/Assets/Plugins/UniTask/Runtime/UniTask.Factory.cs
@@ -194,6 +194,7 @@ namespace Cysharp.Threading.Tasks
         sealed class ExceptionResultSource : IUniTaskSource
         {
             readonly ExceptionDispatchInfo exception;
+            bool calledGet;
 
             public ExceptionResultSource(Exception exception)
             {
@@ -202,6 +203,11 @@ namespace Cysharp.Threading.Tasks
 
             public void GetResult(short token)
             {
+                if (!calledGet)
+                {
+                    calledGet = true;
+                    GC.SuppressFinalize(this);
+                }
                 exception.Throw();
             }
 
@@ -219,11 +225,20 @@ namespace Cysharp.Threading.Tasks
             {
                 continuation(state);
             }
+
+            ~ExceptionResultSource()
+            {
+                if (!calledGet)
+                {
+                    UniTaskScheduler.PublishUnobservedTaskException(exception.SourceException);
+                }
+            }
         }
 
         sealed class ExceptionResultSource<T> : IUniTaskSource<T>
         {
             readonly ExceptionDispatchInfo exception;
+            bool calledGet;
 
             public ExceptionResultSource(Exception exception)
             {
@@ -232,12 +247,22 @@ namespace Cysharp.Threading.Tasks
 
             public T GetResult(short token)
             {
+                if (!calledGet)
+                {
+                    calledGet = true;
+                    GC.SuppressFinalize(this);
+                }
                 exception.Throw();
                 return default;
             }
 
             void IUniTaskSource.GetResult(short token)
             {
+                if (!calledGet)
+                {
+                    calledGet = true;
+                    GC.SuppressFinalize(this);
+                }
                 exception.Throw();
             }
 
@@ -255,6 +280,14 @@ namespace Cysharp.Threading.Tasks
             {
                 continuation(state);
             }
+
+            ~ExceptionResultSource()
+            {
+                if (!calledGet)
+                {
+                    UniTaskScheduler.PublishUnobservedTaskException(exception.SourceException);
+                }
+            }
         }
 
         sealed class CanceledResultSource : IUniTaskSource

From c31b78e45e4de343a05c99d1b04df624b6036e37 Mon Sep 17 00:00:00 2001
From: Artem Perepelitsa <perepelartem@gmail.com>
Date: Sat, 16 Oct 2021 12:18:52 +0300
Subject: [PATCH 2/2] Add a unit test to verify that an unawaited task reports
 exceptions

---
 src/UniTask/Assets/Tests/AsyncTest.cs | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/src/UniTask/Assets/Tests/AsyncTest.cs b/src/UniTask/Assets/Tests/AsyncTest.cs
index c329dbf..75eec2c 100644
--- a/src/UniTask/Assets/Tests/AsyncTest.cs
+++ b/src/UniTask/Assets/Tests/AsyncTest.cs
@@ -366,6 +366,28 @@ namespace Cysharp.Threading.TasksTests
             UniTaskScheduler.UnobservedTaskException -= action;
         });
 
+        [UnityTest]
+        public IEnumerator ThrowExceptionUnawaited() => UniTask.ToCoroutine(async () =>
+        {
+            LogAssert.Expect(LogType.Exception, "Exception: MyException");
+
+#pragma warning disable 1998
+            async UniTask Throw() => throw new Exception("MyException");
+#pragma warning restore 1998
+
+#pragma warning disable 4014
+            Throw();
+#pragma warning restore 4014
+
+            await UniTask.DelayFrame(3);
+
+            GC.Collect();
+            GC.WaitForPendingFinalizers();
+            GC.Collect();
+
+            await UniTask.DelayFrame(1);
+        });
+
         async UniTask InException1()
         {
             await UniTask.Yield();