From 37bb4d38358d9acf97d031e0867388a54124d55a Mon Sep 17 00:00:00 2001
From: stakx <stakx@eml.cc>
Date: Sat, 3 Jun 2017 21:21:18 +0200
Subject: [PATCH] Add `ThrowsAsync` overload for non-generic `Task`

---
 Source/ReturnsExtensions.cs           | 14 ++++++++++++++
 UnitTests/ReturnsExtensionsFixture.cs | 15 +++++++++++++++
 2 files changed, 29 insertions(+)

diff --git a/Source/ReturnsExtensions.cs b/Source/ReturnsExtensions.cs
index 79016d1b8..3ba16ccc6 100644
--- a/Source/ReturnsExtensions.cs
+++ b/Source/ReturnsExtensions.cs
@@ -35,6 +35,20 @@ public static IReturnsResult<TMock> ReturnsAsync<TMock, TResult>(this IReturns<T
 		    return mock.Returns(() => Task.FromResult(valueFunction()));
 		}
 
+        /// <summary>
+        /// Specifies the exception to throw when the asynchronous method is invoked.
+        /// </summary>
+        /// <typeparam name="TMock">Mocked type.</typeparam>
+        /// <param name="mock">Returns verb which represents the mocked type and the task return type</param>
+        /// <param name="exception">Exception instance to throw.</param>
+        public static IReturnsResult<TMock> ThrowsAsync<TMock>(this IReturns<TMock, Task> mock, Exception exception) where TMock : class
+        {
+            var tcs = new TaskCompletionSource<bool>();
+            tcs.SetException(exception);
+
+            return mock.Returns(tcs.Task);
+        }
+
         /// <summary>
         /// Specifies the exception to throw when the asynchronous method is invoked.
         /// </summary>
diff --git a/UnitTests/ReturnsExtensionsFixture.cs b/UnitTests/ReturnsExtensionsFixture.cs
index 0ba895fe1..be2c630ee 100644
--- a/UnitTests/ReturnsExtensionsFixture.cs
+++ b/UnitTests/ReturnsExtensionsFixture.cs
@@ -9,6 +9,8 @@ public class ReturnsExtensionsFixture
     {
         public interface IAsyncInterface
         {
+            Task NoParametersNonGenericTaskReturnType();
+
             Task<string> NoParametersRefReturnType();
             
             Task<int> NoParametersValueReturnType();
@@ -192,6 +194,19 @@ public void ReturnsAsyncFunc_onEachInvocation_RefReturnTypeLazyEvaluation()
             Assert.NotSame(firstEvaluationResult, secondEvaluationResult);
         }
 
+        [Fact]
+        public void ThrowsAsync_on_NoParametersNonGenericTaskReturnType()
+        {
+            var mock = new Mock<IAsyncInterface>();
+            var exception = new InvalidOperationException();
+            mock.Setup(x => x.NoParametersNonGenericTaskReturnType()).ThrowsAsync(exception);
+
+            var task = mock.Object.NoParametersNonGenericTaskReturnType();
+
+            Assert.True(task.IsFaulted);
+            Assert.Equal(exception, task.Exception.InnerException);
+        }
+
         [Fact]
         public void ThrowsAsync_on_NoParametersRefReturnType()
         {