Support parenthesized expressions in SA1139

Author: sharwell

StyleCop.Analyzers/StyleCop.Analyzers.CodeFixes/ReadabilityRules/SA1139CodeFixProvider.cs

@@ -94,11 +94,11 @@ private static async Task<Document> GetTransformedDocumentAsync(Document documen
 
         private static SyntaxNode GenerateReplacementNode(CastExpressionSyntax node)
         {
-            var plusMinusSyntax = node.Expression as PrefixUnaryExpressionSyntax;
+            var plusMinusSyntax = node.Expression.WalkDownParentheses() as PrefixUnaryExpressionSyntax;
             var literalExpressionSyntax =
                 plusMinusSyntax == null ?
-                (LiteralExpressionSyntax)node.Expression :
-                (LiteralExpressionSyntax)plusMinusSyntax.Operand;
+                (LiteralExpressionSyntax)node.Expression.WalkDownParentheses() :
+                (LiteralExpressionSyntax)plusMinusSyntax.Operand.WalkDownParentheses();
             var typeToken = node.Type.GetFirstToken();
             var prefix = plusMinusSyntax == null
                 ? string.Empty

StyleCop.Analyzers/StyleCop.Analyzers.Test/ReadabilityRules/SA1139UnitTests.cs

@@ -72,6 +72,10 @@ public void Method()
         [InlineData("long", "1", "1L")]
         [InlineData("long", "+1", "+1L")]
         [InlineData("long", "-1", "-1L")]
+        [InlineData("long", "(+1)", "+1L")]
+        [InlineData("long", "(-1)", "-1L")]
+        [InlineData("long", "(1)", "1L")]
+        [InlineData("long", "(-(1))", "-1L")]
         [InlineData("ulong", "1", "1UL")]
         [InlineData("ulong", "+1", "+1UL")]
         [InlineData("uint", "1", "1U")]
@@ -175,6 +179,7 @@ public void Method()
         /// <returns>A <see cref="Task"/> representing the asynchronous unit test.</returns>
         [Theory]
         [InlineData("(long)~1")]
+        [InlineData("(long)(~1)")]
         [InlineData("(bool)true")]
         [InlineData("(bool)(false)")]
         [InlineData("(long)~+1")]

StyleCop.Analyzers/StyleCop.Analyzers/Helpers/ExpressionSyntaxHelpers.cs

@@ -0,0 +1,21 @@
+// Copyright (c) Tunnel Vision Laboratories, LLC. All Rights Reserved.
+// Licensed under the Apache License, Version 2.0. See LICENSE in the project root for license information.
+
+namespace StyleCop.Analyzers.Helpers
+{
+    using Microsoft.CodeAnalysis.CSharp.Syntax;
+
+    internal static class ExpressionSyntaxHelpers
+    {
+        public static ExpressionSyntax WalkDownParentheses(this ExpressionSyntax expression)
+        {
+            var result = expression;
+            while (result is ParenthesizedExpressionSyntax parenthesizedExpression)
+            {
+                result = parenthesizedExpression.Expression;
+            }
+
+            return result;
+        }
+    }
+}

StyleCop.Analyzers/StyleCop.Analyzers/ReadabilityRules/SA1139UseLiteralSuffixNotationInsteadOfCasting.cs

@@ -58,7 +58,7 @@ private static void HandleCastExpression(SyntaxNodeAnalysisContext context)
                 return;
             }
 
-            var unaryExpressionSyntax = castExpressionSyntax.Expression as PrefixUnaryExpressionSyntax;
+            var unaryExpressionSyntax = castExpressionSyntax.Expression.WalkDownParentheses() as PrefixUnaryExpressionSyntax;
             if (unaryExpressionSyntax != null)
             {
                 if (unaryExpressionSyntax.Kind() != SyntaxKind.UnaryPlusExpression
@@ -70,8 +70,8 @@ private static void HandleCastExpression(SyntaxNodeAnalysisContext context)
             }
 
             var castedElementTypeSyntax = unaryExpressionSyntax == null
-                ? castExpressionSyntax.Expression as LiteralExpressionSyntax
-                : unaryExpressionSyntax.Operand as LiteralExpressionSyntax;
+                ? castExpressionSyntax.Expression.WalkDownParentheses() as LiteralExpressionSyntax
+                : unaryExpressionSyntax.Operand.WalkDownParentheses() as LiteralExpressionSyntax;
 
             if (castedElementTypeSyntax == null)
             {