Fix handling of nested 'await' expressions during VSTHRD103 code fix

Fixes #329
microsoft · Aug 7, 2018 · ad635ee · ad635ee
1 parent 536bbd5
commit ad635ee
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Showing 2 changed files with 36 additions and 5 deletions.
diff --git a/src/Microsoft.VisualStudio.Threading.Analyzers.Tests/VSTHRD103UseAsyncOptionAnalyzerTests.cs b/src/Microsoft.VisualStudio.Threading.Analyzers.Tests/VSTHRD103UseAsyncOptionAnalyzerTests.cs
@@ -435,6 +435,36 @@ static class Assert {
             this.VerifyCSharpFix(test, withFix);
         }
 
+        [Fact]
+        public void TaskOfTResultInTaskReturningMethodGeneratesWarning_FixRewritesCorrectExpression()
+        {
+            var test = @"
+using System;
+using System.Threading.Tasks;
+
+class Test {
+    async Task T() {
+        await Task.Run(() => Console.Error).Result.WriteLineAsync();
+    }
+}
+";
+
+            var withFix = @"
+using System;
+using System.Threading.Tasks;
+
+class Test {
+    async Task T() {
+        await (await Task.Run(() => Console.Error)).WriteLineAsync();
+    }
+}
+";
+
+            this.expect.Locations = new[] { new DiagnosticResultLocation("Test0.cs", 7, 45) };
+            this.VerifyCSharpDiagnostic(test, this.expect);
+            this.VerifyCSharpFix(test, withFix);
+        }
+
         [Fact]
         public void TaskOfTResultInTaskReturningAnonymousMethodWithinSyncMethod_GeneratesWarning()
         {

diff --git a/src/Microsoft.VisualStudio.Threading.Analyzers/VSTHRD103UseAsyncOptionCodeFix.cs b/src/Microsoft.VisualStudio.Threading.Analyzers/VSTHRD103UseAsyncOptionCodeFix.cs
@@ -170,11 +170,6 @@ protected override async Task<Solution> GetChangedSolutionAsync(CancellationToke
                     awaitExpression = SyntaxFactory.AwaitExpression(
                         syncExpression.ReplaceNode(syncMethodName, asyncMethodName).WithoutLeadingTrivia())
                         .WithLeadingTrivia(syncExpression.GetLeadingTrivia());
-                    if (!(syncExpression.Parent is ExpressionStatementSyntax))
-                    {
-                        awaitExpression = SyntaxFactory.ParenthesizedExpression(awaitExpression)
-                            .WithAdditionalAnnotations(Simplifier.Annotation);
-                    }
                 }
                 else
                 {
@@ -193,6 +188,12 @@ protected override async Task<Solution> GetChangedSolutionAsync(CancellationToke
                         .WithLeadingTrivia(syncMemberStrippedExpression.GetLeadingTrivia());
                 }
 
+                if (!(syncExpression.Parent is ExpressionStatementSyntax))
+                {
+                    awaitExpression = SyntaxFactory.ParenthesizedExpression(awaitExpression)
+                        .WithAdditionalAnnotations(Simplifier.Annotation);
+                }
+
                 updatedMethod = updatedMethod
                     .ReplaceNode(syncExpression, awaitExpression);