Fix analyzer RCS1129 (#1618)

Author: josefpihrt

ChangeLog.md

@@ -7,6 +7,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Fixed
+
+- Fix analyzer [RCS1229](https://josefpihrt.github.io/docs/roslynator/analyzers/RCS1229) ([PR](https://github.com/dotnet/roslynator/pull/1618))
+
 ### Added
 
 - Add analyzer "Put expression body on its own line" [RCS0062](https://josefpihrt.github.io/docs/roslynator/analyzers/RCS0062) ([PR](https://github.com/dotnet/roslynator/pull/1593) by @cbersch)

src/Analyzers/CSharp/Analysis/UseAsyncAwaitAnalyzer.cs

@@ -276,7 +276,7 @@ private bool IsCompletedTask(ExpressionSyntax expression)
 
                 return string.Equals(simpleMemberAccess.Name.Identifier.ValueText, "CompletedTask", StringComparison.Ordinal)
                     && SemanticModel.GetSymbol(expression, CancellationToken) is IPropertySymbol propertySymbol
-                    && IsTaskOrTaskOrT(propertySymbol.ContainingType);
+                    && IsTaskOrTaskOfT(propertySymbol.ContainingType);
             }
             else
             {
@@ -293,7 +293,7 @@ private bool IsCompletedTask(ExpressionSyntax expression)
                             if (SemanticModel.GetSymbol(expression, CancellationToken) is IMethodSymbol methodSymbol
                                 && (methodSymbol.Arity == 0 || methodSymbol.Arity == 1)
                                 && methodSymbol.Parameters.Length == 1
-                                && IsTaskOrTaskOrT(methodSymbol.ContainingType))
+                                && IsTaskOrTaskOfT(methodSymbol.ContainingType))
                             {
                                 return true;
                             }
@@ -307,10 +307,10 @@ private bool IsCompletedTask(ExpressionSyntax expression)
             return false;
         }
 
-        private static bool IsTaskOrTaskOrT(INamedTypeSymbol typeSymbol)
+        private static bool IsTaskOrTaskOfT(INamedTypeSymbol typeSymbol)
         {
-            return typeSymbol.HasMetadataName(MetadataNames.System_Threading_Tasks_Task)
-                || typeSymbol.HasMetadataName(MetadataNames.System_Threading_Tasks_Task_T);
+            return typeSymbol.ContainingNamespace.HasMetadataName(MetadataNames.System_Threading_Tasks)
+                && typeSymbol.MetadataName is "Task" or "Task`1" or "ValueTask" or "ValueTask`1";
         }
 
         public override void VisitLocalFunctionStatement(LocalFunctionStatementSyntax node)

src/Tests/Analyzers.Tests/RCS1229UseAsyncAwaitTests.cs

@@ -809,6 +809,26 @@ NonAwaitableTaskType<int> M2()
 class NonAwaitableTaskType { }
 [AsyncMethodBuilder(null)]
 class NonAwaitableTaskType<T> { }
+");
+    }
+
+    [Fact, Trait(Traits.Analyzer, DiagnosticIdentifiers.UseAsyncAwait)]
+    public async Task TestNoDiagnostic_ValueTask()
+    {
+        await VerifyNoDiagnosticAsync(@"
+using System;
+using System.IO;
+using System.Threading.Tasks;
+
+class C
+{
+    ValueTask M()
+    {
+        using var memoryStream = new MemoryStream();
+
+        return ValueTask.CompletedTask;
+    }
+}
 ");
     }
 }