From b4dde16aa1286d9a9f6a77489a14a4165ee8351c Mon Sep 17 00:00:00 2001
From: Ody Mbegbu <odytrice@gmail.com>
Date: Wed, 23 May 2018 15:52:54 +0100
Subject: [PATCH] Added Support for await keyword

---
 src/Operation/Async.cs   | 66 ++++++++++++++++++++++++++++++++++++++++
 test/Tests/AsyncTests.cs | 61 +++++++++++++++++++++++++++++++++++++
 test/Tests/Tests.csproj  |  2 +-
 3 files changed, 128 insertions(+), 1 deletion(-)
 create mode 100644 src/Operation/Async.cs
 create mode 100644 test/Tests/AsyncTests.cs

diff --git a/src/Operation/Async.cs b/src/Operation/Async.cs
new file mode 100644
index 0000000..da1ab81
--- /dev/null
+++ b/src/Operation/Async.cs
@@ -0,0 +1,66 @@
+using System;
+using System.Collections.Generic;
+using System.Runtime.CompilerServices;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace System
+{
+
+    public static partial class OperationExtensions
+    {
+        public static OperationAwaiter<T> GetAwaiter<T>(this Operation<T> operation)
+        {
+            return new OperationAwaiter<T>(operation);
+        }
+
+        public static OperationAwaiter GetAwaiter(this Operation operation)
+        {
+            return new OperationAwaiter(operation);
+        }
+
+    }
+
+    public class OperationAwaiter : INotifyCompletion
+    {
+        private Operation _operation;
+
+        public OperationAwaiter(Operation operation)
+        {
+            _operation = operation;
+        }
+        public bool IsCompleted => true;
+
+        public void OnCompleted(Action continuation)
+        {
+            continuation();
+        }
+
+        public void GetResult()
+        {
+            _operation.Unwrap();
+        }
+    }
+
+
+    public class OperationAwaiter<T> : INotifyCompletion
+    {
+        private Operation<T> _operation;
+
+        public OperationAwaiter(Operation<T> operation)
+        {
+            _operation = operation;
+        }
+        public bool IsCompleted => true;
+
+        public void OnCompleted(Action continuation)
+        {
+            continuation();
+        }
+
+        public T GetResult()
+        {
+            return _operation.Unwrap();
+        }
+    }
+}
\ No newline at end of file
diff --git a/test/Tests/AsyncTests.cs b/test/Tests/AsyncTests.cs
new file mode 100644
index 0000000..01d7403
--- /dev/null
+++ b/test/Tests/AsyncTests.cs
@@ -0,0 +1,61 @@
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+using System;
+using System.Collections.Generic;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Tests
+{
+    [TestClass]
+    public class AsyncTests
+    {
+        [TestMethod]
+        public async Task AwaitSuccessfulOperation()
+        {
+            var operation = Operation.Success(10);
+
+            var result = await operation;
+
+            Assert.AreEqual(10, result);
+        }
+
+        [TestMethod]
+        public async Task AwaitFailedOperation()
+        {
+            var operation = Operation.Fail<int>("An Error Occured");
+
+            bool failed = false;
+            try
+            {
+                var result = await operation;
+            }
+            catch
+            {
+                failed = true;
+            }
+
+            Assert.IsTrue(failed, "Operation Not Throwing Exception");
+        }
+
+        [TestMethod]
+        public void TestErrorCapturedInTask()
+        { 
+            var result = AsyncOpMethod();
+
+            Assert.IsTrue(result.IsFaulted);
+
+            async Task<int> AsyncOpMethod()
+            {
+                await Operation.Fail<int>("An Error Occured");
+                return 1;
+            }
+        }
+
+        [TestMethod]
+        public async Task AwaitNonGenericOperation()
+        {
+            var operation = Operation.Success();
+            await operation;
+        }
+    }
+}
diff --git a/test/Tests/Tests.csproj b/test/Tests/Tests.csproj
index 9efd5b7..565653d 100644
--- a/test/Tests/Tests.csproj
+++ b/test/Tests/Tests.csproj
@@ -17,7 +17,7 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="15.0.0-preview-20170106-08" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="15.7.2" />
     <PackageReference Include="MSTest.TestAdapter" Version="1.1.18" />
     <PackageReference Include="MSTest.TestFramework" Version="1.1.18" />
   </ItemGroup>