Merge pull request #47372 from Youssef1313/parenthesis-bug

Fix IsSafeToChangeAssociativity for dynamic variables

src/Analyzers/CSharp/Tests/RemoveUnnecessaryParentheses/RemoveUnnecessaryExpressionParenthesesTests.cs

-// Licensed to the .NET Foundation under one or more agreements.
+// Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
@@ -95,6 +95,22 @@ void M()
 }");
         }
 
+        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryParentheses)]
+        [WorkItem(47365, "https://github.com/dotnet/roslyn/issues/47365")]
+        public async Task TestDynamic()
+        {
+            await TestMissingAsync(
+@"class C
+{
+    void M()
+    {
+        dynamic i = 1;
+        dynamic s = ""s"";
+        Console.WriteLine(s + $$(1 + i));
+    }
+}");
+        }
+
         [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryParentheses)]
         public async Task TestArithmeticRequiredForClarity2()
         {

src/Workspaces/SharedUtilitiesAndExtensions/Compiler/Core/Extensions/ParenthesizedExpressionSyntaxExtensions.cs

@@ -40,6 +40,12 @@ internal static class CommonParenthesizedExpressionSyntaxExtensions
                 }
             }
 
+            // It's not safe to change associativity for dynamic variables as the actual type isn't known. See https://github.com/dotnet/roslyn/issues/47365
+            if (innerTypeInfo.Type is IDynamicTypeSymbol)
+            {
+                return false;
+            }
+
             // Only allow us to change associativity if all the types are the same.
             // for example, if we have: int + (int + long)  then we don't want to
             // change things such that we effectively have (int + int) + long