re

Fixed CancelationToken not being passed correctly

README.md

@@ -2,7 +2,7 @@ UniTask
 ===
 [![GitHub Actions](https://github.com/Cysharp/UniTask/workflows/Build-Debug/badge.svg)](https://github.com/Cysharp/UniTask/actions) [![Releases](https://img.shields.io/github/release/Cysharp/UniTask.svg)](https://github.com/Cysharp/UniTask/releases)
 
-Provides an efficient async/await integration to Unity. 
+Provides an efficient allocation free async/await integration to Unity.
 
 * Struct based `UniTask<T>` and custom AsyncMethodBuilder to achive zero allocation
 * All Unity AsyncOperations and Coroutine to awaitable
@@ -13,6 +13,9 @@ Provides an efficient async/await integration to Unity.
 * TaskTracker window to prevent memory leak
 * Highly compatible behaviour with Task/ValueTask/IValueTaskSource
 
+Techinical details, see blog post: [UniTask v2 — Zero Allocation async/await for Unity, with Asynchronous LINQ
+](https://medium.com/@neuecc/unitask-v2-zero-allocation-async-await-for-unity-with-asynchronous-linq-1aa9c96aa7dd)
+
 <!-- START doctoc generated TOC please keep comment here to allow auto update -->
 <!-- DON'T EDIT THIS SECTION, INSTEAD RE-RUN doctoc TO UPDATE -->
 ## Table of Contents
@@ -778,7 +781,7 @@ After Unity 2019.3.4f1, Unity 2020.1a21, that support path query parameter of gi
 
 or add `"com.cysharp.unitask": "https://github.com/Cysharp/UniTask.git?path=src/UniTask/Assets/Plugins/UniTask"` to `Packages/manifest.json`.
 
-If you want to set a target version, UniTask is using `*.*.*` release tag so you can specify a version like `#2.0.15`. For example `https://github.com/Cysharp/UniTask.git?path=src/UniTask/Assets/Plugins/UniTask#2.0.15`.
+If you want to set a target version, UniTask is using `*.*.*` release tag so you can specify a version like `#2.0.18`. For example `https://github.com/Cysharp/UniTask.git?path=src/UniTask/Assets/Plugins/UniTask#2.0.18`.
 
 ### Install via OpenUPM
 

src/UniTask.NetCore/NetCore/AsyncEnumerableExtensions.cs

@@ -0,0 +1,101 @@
+#if !NETSTANDARD2_0
+
+#pragma warning disable 0649
+
+using System;
+using System.Collections.Generic;
+using System.Threading;
+using System.Threading.Tasks;
+using System.Threading.Tasks.Sources;
+
+namespace Cysharp.Threading.Tasks
+{
+    public static class AsyncEnumerableExtensions
+    {
+        public static IUniTaskAsyncEnumerable<T> AsUniTaskAsyncEnumerable<T>(this IAsyncEnumerable<T> source)
+        {
+            return new AsyncEnumerableToUniTaskAsyncEnumerable<T>(source);
+        }
+
+        public static IAsyncEnumerable<T> AsAsyncEnumerable<T>(this IUniTaskAsyncEnumerable<T> source)
+        {
+            return new UniTaskAsyncEnumerableToAsyncEnumerable<T>(source);
+        }
+
+        sealed class AsyncEnumerableToUniTaskAsyncEnumerable<T> : IUniTaskAsyncEnumerable<T>
+        {
+            readonly IAsyncEnumerable<T> source;
+
+            public AsyncEnumerableToUniTaskAsyncEnumerable(IAsyncEnumerable<T> source)
+            {
+                this.source = source;
+            }
+
+            public IUniTaskAsyncEnumerator<T> GetAsyncEnumerator(CancellationToken cancellationToken = default)
+            {
+                return new Enumerator(source.GetAsyncEnumerator(cancellationToken));
+            }
+
+            sealed class Enumerator : IUniTaskAsyncEnumerator<T>
+            {
+                readonly IAsyncEnumerator<T> enumerator;
+
+                public Enumerator(IAsyncEnumerator<T> enumerator)
+                {
+                    this.enumerator = enumerator;
+                }
+
+                public T Current => enumerator.Current;
+
+                public async UniTask DisposeAsync()
+                {
+                    await enumerator.DisposeAsync();
+                }
+
+                public async UniTask<bool> MoveNextAsync()
+                {
+                    return await enumerator.MoveNextAsync();
+                }
+            }
+        }
+
+        sealed class UniTaskAsyncEnumerableToAsyncEnumerable<T> : IAsyncEnumerable<T>
+        {
+            readonly IUniTaskAsyncEnumerable<T> source;
+
+            public UniTaskAsyncEnumerableToAsyncEnumerable(IUniTaskAsyncEnumerable<T> source)
+            {
+                this.source = source;
+            }
+
+            public IAsyncEnumerator<T> GetAsyncEnumerator(CancellationToken cancellationToken = default)
+            {
+                return new Enumerator(source.GetAsyncEnumerator(cancellationToken));
+            }
+
+            sealed class Enumerator : IAsyncEnumerator<T>
+            {
+                readonly IUniTaskAsyncEnumerator<T> enumerator;
+
+                public Enumerator(IUniTaskAsyncEnumerator<T> enumerator)
+                {
+                    this.enumerator = enumerator;
+                }
+
+                public T Current => enumerator.Current;
+
+                public ValueTask DisposeAsync()
+                {
+                    return enumerator.DisposeAsync();
+                }
+
+                public ValueTask<bool> MoveNextAsync()
+                {
+                    return enumerator.MoveNextAsync();
+                }
+            }
+        }
+    }
+}
+
+#endif

src/UniTask.NetCore/NetCore/UniTask.AsValueTask.cs

@@ -26,15 +26,14 @@ namespace Cysharp.Threading.Tasks
 #endif
         }
 
-        public static UniTask<T> AsUniTask<T>(this ValueTask<T> task, bool useCurrentSynchronizationContext = true)
+        public static async UniTask<T> AsUniTask<T>(this ValueTask<T> task)
         {
-            // NOTE: get _obj and _token directly for low overhead conversion but not yet implemented.
+            return await task;
-            return task.AsTask().AsUniTask(useCurrentSynchronizationContext);
         }
 
-        public static UniTask AsUniTask(this ValueTask task, bool useCurrentSynchronizationContext = true)
+        public static async UniTask AsUniTask(this ValueTask task)
         {
-            return task.AsTask().AsUniTask(useCurrentSynchronizationContext);
+            await task;
         }
 
 #if NETSTANDARD2_0

src/UniTask/Assets/Plugins/UniTask/Runtime/Linq/Subscribe.cs

@@ -0,0 +1,313 @@
+using Cysharp.Threading.Tasks.Internal;
+using System;
+using System.Threading;
+using Subscribes = Cysharp.Threading.Tasks.Linq.Subscribe;
+
+namespace Cysharp.Threading.Tasks.Linq
+{
+    public static partial class UniTaskAsyncEnumerable
+    {
+        // OnNext
+
+        public static IDisposable Subscribe<TSource>(this IUniTaskAsyncEnumerable<TSource> source, Action<TSource> action)
+        {
+            Error.ThrowArgumentNullException(source, nameof(source));
+            Error.ThrowArgumentNullException(action, nameof(action));
+
+            var cts = new CancellationTokenDisposable();
+            Subscribes.SubscribeCore(source, action, Subscribes.NopError, Subscribes.NopCompleted, cts.Token).Forget();
+            return cts;
+        }
+
+        public static IDisposable Subscribe<TSource>(this IUniTaskAsyncEnumerable<TSource> source, Func<TSource, UniTaskVoid> action)
+        {
+            Error.ThrowArgumentNullException(source, nameof(source));
+            Error.ThrowArgumentNullException(action, nameof(action));
+
+            var cts = new CancellationTokenDisposable();
+            Subscribes.SubscribeCore(source, action, Subscribes.NopError, Subscribes.NopCompleted, cts.Token).Forget();
+            return cts;
+        }
+
+        public static IDisposable Subscribe<TSource>(this IUniTaskAsyncEnumerable<TSource> source, Func<TSource, CancellationToken, UniTaskVoid> action)
+        {
+            Error.ThrowArgumentNullException(source, nameof(source));
+            Error.ThrowArgumentNullException(action, nameof(action));
+
+            var cts = new CancellationTokenDisposable();
+            Subscribes.SubscribeCore(source, action, Subscribes.NopError, Subscribes.NopCompleted, cts.Token).Forget();
+            return cts;
+        }
+
+        public static void Subscribe<TSource>(this IUniTaskAsyncEnumerable<TSource> source, Action<TSource> action, CancellationToken cancellationToken)
+        {
+            Error.ThrowArgumentNullException(source, nameof(source));
+            Error.ThrowArgumentNullException(action, nameof(action));
+
+            Subscribes.SubscribeCore(source, action, Subscribes.NopError, Subscribes.NopCompleted, cancellationToken).Forget();
+        }
+
+        public static void Subscribe<TSource>(this IUniTaskAsyncEnumerable<TSource> source, Func<TSource, UniTaskVoid> action, CancellationToken cancellationToken)
+        {
+            Error.ThrowArgumentNullException(source, nameof(source));
+            Error.ThrowArgumentNullException(action, nameof(action));
+
+            Subscribes.SubscribeCore(source, action, Subscribes.NopError, Subscribes.NopCompleted, cancellationToken).Forget();
+        }
+
+        public static void Subscribe<TSource>(this IUniTaskAsyncEnumerable<TSource> source, Func<TSource, CancellationToken, UniTaskVoid> action, CancellationToken cancellationToken)
+        {
+            Error.ThrowArgumentNullException(source, nameof(source));
+            Error.ThrowArgumentNullException(action, nameof(action));
+
+            Subscribes.SubscribeCore(source, action, Subscribes.NopError, Subscribes.NopCompleted, cancellationToken).Forget();
+        }
+
+        // OnNext, OnError
+
+        public static IDisposable Subscribe<TSource>(this IUniTaskAsyncEnumerable<TSource> source, Action<TSource> onNext, Action<Exception> onError)
+        {
+            Error.ThrowArgumentNullException(source, nameof(source));
+            Error.ThrowArgumentNullException(onNext, nameof(onNext));
+            Error.ThrowArgumentNullException(onError, nameof(onError));
+
+            var cts = new CancellationTokenDisposable();
+            Subscribes.SubscribeCore(source, onNext, onError, Subscribes.NopCompleted, cts.Token).Forget();
+            return cts;
+        }
+
+        public static IDisposable Subscribe<TSource>(this IUniTaskAsyncEnumerable<TSource> source, Func<TSource, UniTaskVoid> onNext, Action<Exception> onError)
+        {
+            Error.ThrowArgumentNullException(source, nameof(source));
+            Error.ThrowArgumentNullException(onNext, nameof(onNext));
+            Error.ThrowArgumentNullException(onError, nameof(onError));
+
+            var cts = new CancellationTokenDisposable();
+            Subscribes.SubscribeCore(source, onNext, onError, Subscribes.NopCompleted, cts.Token).Forget();
+            return cts;
+        }
+
+        public static void Subscribe<TSource>(this IUniTaskAsyncEnumerable<TSource> source, Action<TSource> onNext, Action<Exception> onError, CancellationToken cancellationToken)
+        {
+            Error.ThrowArgumentNullException(source, nameof(source));
+            Error.ThrowArgumentNullException(onNext, nameof(onNext));
+            Error.ThrowArgumentNullException(onError, nameof(onError));
+
+            Subscribes.SubscribeCore(source, onNext, onError, Subscribes.NopCompleted, cancellationToken).Forget();
+        }
+
+        public static void Subscribe<TSource>(this IUniTaskAsyncEnumerable<TSource> source, Func<TSource, UniTaskVoid> onNext, Action<Exception> onError, CancellationToken cancellationToken)
+        {
+            Error.ThrowArgumentNullException(source, nameof(source));
+            Error.ThrowArgumentNullException(onNext, nameof(onNext));
+            Error.ThrowArgumentNullException(onError, nameof(onError));
+
+            Subscribes.SubscribeCore(source, onNext, onError, Subscribes.NopCompleted, cancellationToken).Forget();
+        }
+
+        // OnNext, OnCompleted
+
+        public static IDisposable Subscribe<TSource>(this IUniTaskAsyncEnumerable<TSource> source, Action<TSource> onNext, Action onCompleted)
+        {
+            Error.ThrowArgumentNullException(source, nameof(source));
+            Error.ThrowArgumentNullException(onNext, nameof(onNext));
+            Error.ThrowArgumentNullException(onCompleted, nameof(onCompleted));
+
+            var cts = new CancellationTokenDisposable();
+            Subscribes.SubscribeCore(source, onNext, Subscribes.NopError, onCompleted, cts.Token).Forget();
+            return cts;
+        }
+
+        public static IDisposable Subscribe<TSource>(this IUniTaskAsyncEnumerable<TSource> source, Func<TSource, UniTaskVoid> onNext, Action onCompleted)
+        {
+            Error.ThrowArgumentNullException(source, nameof(source));
+            Error.ThrowArgumentNullException(onNext, nameof(onNext));
+            Error.ThrowArgumentNullException(onCompleted, nameof(onCompleted));
+
+            var cts = new CancellationTokenDisposable();
+            Subscribes.SubscribeCore(source, onNext, Subscribes.NopError, onCompleted, cts.Token).Forget();
+            return cts;
+        }
+
+        public static void Subscribe<TSource>(this IUniTaskAsyncEnumerable<TSource> source, Action<TSource> onNext, Action onCompleted, CancellationToken cancellationToken)
+        {
+            Error.ThrowArgumentNullException(source, nameof(source));
+            Error.ThrowArgumentNullException(onNext, nameof(onNext));
+            Error.ThrowArgumentNullException(onCompleted, nameof(onCompleted));
+
+            Subscribes.SubscribeCore(source, onNext, Subscribes.NopError, onCompleted, cancellationToken).Forget();
+        }
+
+        public static void Subscribe<TSource>(this IUniTaskAsyncEnumerable<TSource> source, Func<TSource, UniTaskVoid> onNext, Action onCompleted, CancellationToken cancellationToken)
+        {
+            Error.ThrowArgumentNullException(source, nameof(source));
+            Error.ThrowArgumentNullException(onNext, nameof(onNext));
+            Error.ThrowArgumentNullException(onCompleted, nameof(onCompleted));
+
+            Subscribes.SubscribeCore(source, onNext, Subscribes.NopError, onCompleted, cancellationToken).Forget();
+        }
+
+        // IObserver
+
+        public static IDisposable Subscribe<TSource>(this IUniTaskAsyncEnumerable<TSource> source, IObserver<TSource> observer)
+        {
+            Error.ThrowArgumentNullException(source, nameof(source));
+            Error.ThrowArgumentNullException(observer, nameof(observer));
+
+            var cts = new CancellationTokenDisposable();
+            Subscribes.SubscribeCore(source, observer, cts.Token).Forget();
+            return cts;
+        }
+
+        public static void Subscribe<TSource>(this IUniTaskAsyncEnumerable<TSource> source, IObserver<TSource> observer, CancellationToken cancellationToken)
+        {
+            Error.ThrowArgumentNullException(source, nameof(source));
+            Error.ThrowArgumentNullException(observer, nameof(observer));
+
+            Subscribes.SubscribeCore(source, observer, cancellationToken).Forget();
+        }
+    }
+
+    internal sealed class CancellationTokenDisposable : IDisposable
+    {
+        readonly CancellationTokenSource cts = new CancellationTokenSource();
+
+        public CancellationToken Token => cts.Token;
+
+        public void Dispose()
+        {
+            if (!cts.IsCancellationRequested)
+            {
+                cts.Cancel();
+            }
+        }
+    }
+
+    internal static class Subscribe
+    {
+        public static readonly Action<Exception> NopError = _ => { };
+        public static readonly Action NopCompleted = () => { };
+
+        public static async UniTaskVoid SubscribeCore<TSource>(IUniTaskAsyncEnumerable<TSource> source, Action<TSource> onNext, Action<Exception> onError, Action onCompleted, CancellationToken cancellationToken)
+        {
+            var e = source.GetAsyncEnumerator(cancellationToken);
+            try
+            {
+                while (await e.MoveNextAsync())
+                {
+                    onNext(e.Current);
+                }
+                onCompleted();
+            }
+            catch (Exception ex)
+            {
+                if (onError == NopError)
+                {
+                    UniTaskScheduler.PublishUnobservedTaskException(ex);
+                    return;
+                }
+
+                if (ex is OperationCanceledException) return;
+
+                onError(ex);
+            }
+            finally
+            {
+                if (e != null)
+                {
+                    await e.DisposeAsync();
+                }
+            }
+        }
+
+        public static async UniTaskVoid SubscribeCore<TSource>(IUniTaskAsyncEnumerable<TSource> source, Func<TSource, UniTaskVoid> onNext, Action<Exception> onError, Action onCompleted, CancellationToken cancellationToken)
+        {
+            var e = source.GetAsyncEnumerator(cancellationToken);
+            try
+            {
+                while (await e.MoveNextAsync())
+                {
+                    onNext(e.Current).Forget();
+                }
+                onCompleted();
+            }
+            catch (Exception ex)
+            {
+                if (onError == NopError)
+                {
+                    UniTaskScheduler.PublishUnobservedTaskException(ex);
+                    return;
+                }
+
+                if (ex is OperationCanceledException) return;
+
+                onError(ex);
+            }
+            finally
+            {
+                if (e != null)
+                {
+                    await e.DisposeAsync();
+                }
+            }
+        }
+
+        public static async UniTaskVoid SubscribeCore<TSource>(IUniTaskAsyncEnumerable<TSource> source, Func<TSource, CancellationToken, UniTaskVoid> onNext, Action<Exception> onError, Action onCompleted, CancellationToken cancellationToken)
+        {
+            var e = source.GetAsyncEnumerator(cancellationToken);
+            try
+            {
+                while (await e.MoveNextAsync())
+                {
+                    onNext(e.Current, cancellationToken).Forget();
+                }
+                onCompleted();
+            }
+            catch (Exception ex)
+            {
+                if (onError == NopError)
+                {
+                    UniTaskScheduler.PublishUnobservedTaskException(ex);
+                    return;
+                }
+
+                if (ex is OperationCanceledException) return;
+
+                onError(ex);
+            }
+            finally
+            {
+                if (e != null)
+                {
+                    await e.DisposeAsync();
+                }
+            }
+        }
+
+        public static async UniTaskVoid SubscribeCore<TSource>(IUniTaskAsyncEnumerable<TSource> source, IObserver<TSource> observer, CancellationToken cancellationToken)
+        {
+            var e = source.GetAsyncEnumerator(cancellationToken);
+            try
+            {
+                while (await e.MoveNextAsync())
+                {
+                    observer.OnNext(e.Current);
+                }
+                observer.OnCompleted();
+            }
+            catch (Exception ex)
+            {
+                if (ex is OperationCanceledException) return;
+
+                observer.OnError(ex);
+            }
+            finally
+            {
+                if (e != null)
+                {
+                    await e.DisposeAsync();
+                }
+            }
+        }
+    }
+}

src/UniTask/Assets/Plugins/UniTask/Runtime/Linq/Subscribe.cs.meta

@@ -0,0 +1,11 @@
+fileFormatVersion: 2
+guid: 263479eb04c189741931fc0e2f615c2d
+MonoImporter:
+  externalObjects: {}
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

src/UniTask/Assets/Plugins/UniTask/Runtime/Linq/ToUniTaskAsyncEnumerable.cs

@@ -248,15 +248,18 @@ namespace Cysharp.Threading.Tasks.Linq
                         return current;
                     }
 
-                    if (queuedResult.Count != 0)
+                    lock (queuedResult)
                     {
-                        current = queuedResult.Dequeue();
+                        if (queuedResult.Count != 0)
-                        useCachedCurrent = true;
+                        {
-                        return current;
+                            current = queuedResult.Dequeue();
-                    }
+                            useCachedCurrent = true;
-                    else
+                            return current;
-                    {
+                        }
-                        return default; // undefined.
+                        else
+                        {
+                            return default; // undefined.
+                        }
                     }
                 }
             }

src/UniTask/Assets/Plugins/UniTask/Runtime/Linq/UnityExtensions/EveryUpdate.cs

@@ -34,6 +34,7 @@ namespace Cysharp.Threading.Tasks.Linq
             public _EveryUpdate(PlayerLoopTiming updateTiming, CancellationToken cancellationToken)
             {
                 this.updateTiming = updateTiming;
+                this.cancellationToken = cancellationToken;
 
                 TaskTracker.TrackActiveTask(this, 2);
                 PlayerLoopHelper.AddAction(updateTiming, this);

src/UniTask/Assets/Plugins/UniTask/Runtime/Linq/UnityExtensions/Timer.cs

@@ -104,6 +104,7 @@ namespace Cysharp.Threading.Tasks.Linq
                 this.dueTimePhase = true;
                 this.updateTiming = updateTiming;
                 this.ignoreTimeScale = ignoreTimeScale;
+                this.cancellationToken = cancellationToken;
                 TaskTracker.TrackActiveTask(this, 2);
                 PlayerLoopHelper.AddAction(updateTiming, this);
             }
@@ -223,6 +224,7 @@ namespace Cysharp.Threading.Tasks.Linq
                 this.dueTimePhase = true;
                 this.dueTimeFrameCount = dueTimeFrameCount;
                 this.periodFrameCount = periodFrameCount;
+                this.cancellationToken = cancellationToken;
 
                 TaskTracker.TrackActiveTask(this, 2);
                 PlayerLoopHelper.AddAction(updateTiming, this);

src/UniTask/Assets/Plugins/UniTask/Runtime/UnityAsyncExtensions.cs

@@ -1285,12 +1285,20 @@ namespace Cysharp.Threading.Tasks
                     continuationAction = null;
                     var result = asyncOperation.webRequest;
                     asyncOperation = null;
+                    if (result.isHttpError || result.isNetworkError)
+                    {
+                        throw new UnityWebRequestException(result);
+                    }
                     return result;
                 }
                 else
                 {
                     var result = asyncOperation.webRequest;
                     asyncOperation = null;
+                    if (result.isHttpError || result.isNetworkError)
+                    {
+                        throw new UnityWebRequestException(result);
+                    }
                     return result;
                 }
             }
@@ -1367,7 +1375,15 @@ namespace Cysharp.Threading.Tasks
                 else
                 {
                     completed = true;
-                    core.TrySetResult(asyncOperation.webRequest);
+                    var result = asyncOperation.webRequest;
+                    if (result.isHttpError || result.isNetworkError)
+                    {
+                        core.TrySetException(new UnityWebRequestException(result));
+                    }
+                    else
+                    {
+                        core.TrySetResult(result);
+                    }
                 }
             }
 
@@ -1526,7 +1542,14 @@ namespace Cysharp.Threading.Tasks
 
                 if (asyncOperation.isDone)
                 {
-                    core.TrySetResult(asyncOperation.webRequest);
+                    if (asyncOperation.webRequest.isHttpError || asyncOperation.webRequest.isNetworkError)
+                    {
+                        core.TrySetException(new UnityWebRequestException(asyncOperation.webRequest));
+                    }
+                    else
+                    {
+                        core.TrySetResult(asyncOperation.webRequest);
+                    }
                     return false;
                 }
 

src/UniTask/Assets/Plugins/UniTask/Runtime/UnityAsyncExtensions.tt

@@ -81,6 +81,12 @@ namespace Cysharp.Threading.Tasks
 <# if (!IsVoid(t)) { #>
                     var result = <#= $"asyncOperation.{t.returnField}" #>;
                     asyncOperation = null;
+<# if(t.returnType == "UnityWebRequest") { #>
+                    if (result.isHttpError || result.isNetworkError)
+                    {
+                        throw new UnityWebRequestException(result);
+                    }
+<# } #>
                     return result;
 <# } else { #>
                     asyncOperation = null;
@@ -91,6 +97,12 @@ namespace Cysharp.Threading.Tasks
 <# if (!IsVoid(t)) { #>
                     var result = <#= $"asyncOperation.{t.returnField}" #>;
                     asyncOperation = null;
+<# if(t.returnType == "UnityWebRequest") { #>
+                    if (result.isHttpError || result.isNetworkError)
+                    {
+                        throw new UnityWebRequestException(result);
+                    }
+<# } #>
                     return result;
 <# } else { #>
                     asyncOperation = null;
@@ -170,7 +182,19 @@ namespace Cysharp.Threading.Tasks
                 else
                 {
                     completed = true;
+<# if(t.returnType == "UnityWebRequest") { #>
+                    var result = asyncOperation.webRequest;
+                    if (result.isHttpError || result.isNetworkError)
+                    {
+                        core.TrySetException(new UnityWebRequestException(result));
+                    }
+                    else
+                    {
+                        core.TrySetResult(result);
+                    }
+<# } else { #>
                     core.TrySetResult(<#= IsVoid(t) ? "AsyncUnit.Default" : $"asyncOperation.{t.returnField}" #>);
+<# } #>
                 }
             }
 
@@ -345,7 +369,18 @@ namespace Cysharp.Threading.Tasks
 
                 if (asyncOperation.isDone)
                 {
+<# if(t.returnType == "UnityWebRequest") { #>
+                    if (asyncOperation.webRequest.isHttpError || asyncOperation.webRequest.isNetworkError)
+                    {
+                        core.TrySetException(new UnityWebRequestException(asyncOperation.webRequest));
+                    }
+                    else
+                    {
+                        core.TrySetResult(asyncOperation.webRequest);
+                    }
+<# } else { #>
                     core.TrySetResult(<#= IsVoid(t) ? "AsyncUnit.Default" : $"asyncOperation.{t.returnField}" #>);
+<# } #>
                     return false;
                 }
 

src/UniTask/Assets/Plugins/UniTask/Runtime/UnityWebRequestError.cs

@@ -0,0 +1,24 @@
+#if ENABLE_UNITYWEBREQUEST
+
+using System;
+using UnityEngine.Networking;
+
+namespace Cysharp.Threading.Tasks
+{
+    public class UnityWebRequestException : Exception
+    {
+        public UnityWebRequest UnityWebRequest { get; }
+        public bool IsNetworkError { get; }
+        public bool IsHttpError { get; }
+
+        public UnityWebRequestException(UnityWebRequest unityWebRequest)
+            : base(unityWebRequest.error + Environment.NewLine + unityWebRequest.downloadHandler.text)
+        {
+            this.UnityWebRequest = unityWebRequest;
+            this.IsNetworkError = unityWebRequest.isNetworkError;
+            this.IsHttpError = unityWebRequest.isHttpError;
+        }
+    }
+}
+
+#endif

src/UniTask/Assets/Plugins/UniTask/Runtime/UnityWebRequestError.cs.meta

@@ -0,0 +1,11 @@
+fileFormatVersion: 2
+guid: 013a499e522703a42962a779b4d9850c
+MonoImporter:
+  externalObjects: {}
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

src/UniTask/Assets/Plugins/UniTask/package.json

@@ -1,7 +1,7 @@
 {
     "name": "com.cysharp.unitask",
     "displayName": "UniTask",
-    "version": "2.0.16",
+    "version": "2.0.18",
     "unity": "2018.4",
     "description": "Provides an efficient async/await integration to Unity.",
     "keywords": [ "async/await", "async", "Task", "UniTask" ],

src/UniTask/Assets/Scenes/SandboxMain.cs

@@ -415,15 +415,12 @@ public class SandboxMain : MonoBehaviour
 
     private async UniTaskVoid ExecuteAsync()
     {
-        Debug.Log("1");
+        var req = UnityWebRequest.Get("https://google.com/");
-        {
+
-            var xs = await UniTaskAsyncEnumerable.TimerFrame(1).ToArrayAsync();
+        var v = await req.SendWebRequest().ToUniTask();
-        }
+        // req.Dispose();
-        Debug.Log("------------------");
+        Debug.Log($"{v.isDone} {v.isHttpError} {v.isNetworkError}");
-        {
+        Debug.Log(v.downloadHandler.text);
-            var xs = await UniTaskAsyncEnumerable.TimerFrame(1).ToArrayAsync();
-            Debug.Log("2");
-        }
     }