From 15fb7d225ae16de10725b4d0e6e1afcb52e02cb9 Mon Sep 17 00:00:00 2001
From: Manfred Brands <m.brands@fugro.com>
Date: Mon, 13 Jul 2020 20:40:03 +0800
Subject: [PATCH] #258: Deal with untyped Tasks

---
 .../EqualToIncompatibleTypesAnalyzerTests.cs  | 21 +++++++++++++++++++
 .../NullConstraintUsageAnalyzerTests.cs       | 11 ++++++++++
 src/nunit.analyzers.tests/TestUtility.cs      |  9 ++++++++
 src/nunit.analyzers/Helpers/AssertHelper.cs   |  2 +-
 4 files changed, 42 insertions(+), 1 deletion(-)

diff --git a/src/nunit.analyzers.tests/EqualToIncompatibleTypes/EqualToIncompatibleTypesAnalyzerTests.cs b/src/nunit.analyzers.tests/EqualToIncompatibleTypes/EqualToIncompatibleTypesAnalyzerTests.cs
index cda7ba6b..50689b26 100644
--- a/src/nunit.analyzers.tests/EqualToIncompatibleTypes/EqualToIncompatibleTypesAnalyzerTests.cs
+++ b/src/nunit.analyzers.tests/EqualToIncompatibleTypes/EqualToIncompatibleTypesAnalyzerTests.cs
@@ -809,5 +809,26 @@ public void NoDiagnosticWhenCombinedConstraintAndUseAllOperator()
 
             AnalyzerAssert.Valid(analyzer, testCode);
         }
+
+        [Test]
+        public void NoDiagnosticWhenComparingTask()
+        {
+            var testCode = TestUtility.WrapInAsyncTestMethod(@"
+                Task wait = Task.CompletedTask;
+                Assert.That(await Task.WhenAny(wait).ConfigureAwait(false), Is.EqualTo(wait));");
+
+            AnalyzerAssert.Valid(analyzer, testCode);
+        }
+
+        [Test]
+        public void NoDiagnosticWhenComparingTask2()
+        {
+            var testCode = TestUtility.WrapInTestMethod(@"
+                Task task1 = Task.CompletedTask;
+                Task task2 = Task.CompletedTask;
+                Assert.That(task1, Is.SameAs(task2));");
+
+            AnalyzerAssert.Valid(analyzer, testCode);
+        }
     }
 }
diff --git a/src/nunit.analyzers.tests/NullConstraintUsage/NullConstraintUsageAnalyzerTests.cs b/src/nunit.analyzers.tests/NullConstraintUsage/NullConstraintUsageAnalyzerTests.cs
index 16bf45f5..afc1869c 100644
--- a/src/nunit.analyzers.tests/NullConstraintUsage/NullConstraintUsageAnalyzerTests.cs
+++ b/src/nunit.analyzers.tests/NullConstraintUsage/NullConstraintUsageAnalyzerTests.cs
@@ -84,5 +84,16 @@ public void TestMethod()
 
             AnalyzerAssert.Valid(analyzer, testCode);
         }
+
+        [TestCase("Is.Null")]
+        [TestCase("Is.Not.Null")]
+        public void ValidWhenActualIsTask(string constraint)
+        {
+            var testCode = TestUtility.WrapInTestMethod($@"
+                var task = Task.CompletedTask;
+                Assert.That(task, {constraint});");
+
+            AnalyzerAssert.Valid(analyzer, testCode);
+        }
     }
 }
diff --git a/src/nunit.analyzers.tests/TestUtility.cs b/src/nunit.analyzers.tests/TestUtility.cs
index 063a8f9d..75c7d691 100644
--- a/src/nunit.analyzers.tests/TestUtility.cs
+++ b/src/nunit.analyzers.tests/TestUtility.cs
@@ -39,5 +39,14 @@ public void TestMethod()
         {{{code}
         }}", additionalUsings);
         }
+
+        internal static string WrapInAsyncTestMethod(string code, string additionalUsings = null)
+        {
+            return WrapMethodInClassNamespaceAndAddUsings($@"
+        [Test]
+        public async Task TestMethod()
+        {{{code}
+        }}", additionalUsings);
+        }
     }
 }
diff --git a/src/nunit.analyzers/Helpers/AssertHelper.cs b/src/nunit.analyzers/Helpers/AssertHelper.cs
index b39f46ee..1e7fe3c5 100644
--- a/src/nunit.analyzers/Helpers/AssertHelper.cs
+++ b/src/nunit.analyzers/Helpers/AssertHelper.cs
@@ -46,7 +46,7 @@ public static ITypeSymbol UnwrapActualType(ITypeSymbol actualType)
             if (actualType is INamedTypeSymbol namedType && namedType.DelegateInvokeMethod != null)
                 actualType = namedType.DelegateInvokeMethod.ReturnType;
 
-            if (actualType.IsAwaitable(out var awaitReturnType))
+            if (actualType.IsAwaitable(out var awaitReturnType) && awaitReturnType.SpecialType != SpecialType.System_Void)
                 actualType = awaitReturnType;
 
             return actualType;