From f09cd8dcb472d1bf745c2091c518c0f70501b183 Mon Sep 17 00:00:00 2001
From: Sam Harwell <sam@tunnelvisionlabs.com>
Date: Sat, 5 Dec 2020 12:29:27 -0800
Subject: [PATCH] Fix SA1008 handling of parenthesized patterns

Fixes #3230
---
 .../SpacingRules/SA1008CSharp9UnitTests.cs    | 55 +++++++++++++++++++
 .../Lightup/SyntaxKindEx.cs                   |  1 +
 ...OpeningParenthesisMustBeSpacedCorrectly.cs |  7 ++-
 3 files changed, 62 insertions(+), 1 deletion(-)

diff --git a/StyleCop.Analyzers/StyleCop.Analyzers.Test.CSharp9/SpacingRules/SA1008CSharp9UnitTests.cs b/StyleCop.Analyzers/StyleCop.Analyzers.Test.CSharp9/SpacingRules/SA1008CSharp9UnitTests.cs
index effd6ee3f..e24b02734 100644
--- a/StyleCop.Analyzers/StyleCop.Analyzers.Test.CSharp9/SpacingRules/SA1008CSharp9UnitTests.cs
+++ b/StyleCop.Analyzers/StyleCop.Analyzers.Test.CSharp9/SpacingRules/SA1008CSharp9UnitTests.cs
@@ -3,9 +3,64 @@
 
 namespace StyleCop.Analyzers.Test.CSharp9.SpacingRules
 {
+    using System.Threading;
+    using System.Threading.Tasks;
+    using Microsoft.CodeAnalysis.CSharp;
+    using Microsoft.CodeAnalysis.Testing;
     using StyleCop.Analyzers.Test.CSharp8.SpacingRules;
+    using Xunit;
+    using static StyleCop.Analyzers.SpacingRules.SA1008OpeningParenthesisMustBeSpacedCorrectly;
+    using static StyleCop.Analyzers.Test.Verifiers.StyleCopCodeFixVerifier<
+        StyleCop.Analyzers.SpacingRules.SA1008OpeningParenthesisMustBeSpacedCorrectly,
+        StyleCop.Analyzers.SpacingRules.TokenSpacingCodeFixProvider>;
 
     public class SA1008CSharp9UnitTests : SA1008CSharp8UnitTests
     {
+        [Fact]
+        [WorkItem(3230, "https://github.com/DotNetAnalyzers/StyleCopAnalyzers/issues/3230")]
+        public async Task TestParenthesizedPatternAsync()
+        {
+            const string testCode = @"
+class C
+{
+    void Method(int b)
+    {
+        _ = b is{|#0:(|} >= 0 and <= 31) or 127;
+        _ = b is{|#1:(|}>= 0 and <= 31) or 127;
+        _ = b is {|#2:(|} >= 0 and <= 31) or 127;
+    }
+}";
+            const string fixedCode = @"
+class C
+{
+    void Method(int b)
+    {
+        _ = b is (>= 0 and <= 31) or 127;
+        _ = b is (>= 0 and <= 31) or 127;
+        _ = b is (>= 0 and <= 31) or 127;
+    }
+}";
+
+            await new CSharpTest(LanguageVersion.CSharp9)
+            {
+                ReferenceAssemblies = ReferenceAssemblies.Net.Net50,
+                ExpectedDiagnostics =
+                {
+                    // /0/Test0.cs(6,17): warning SA1008: Opening parenthesis should be preceded by a space.
+                    Diagnostic(DescriptorPreceded).WithLocation(0),
+
+                    // /0/Test0.cs(6,17): warning SA1008: Opening parenthesis should not be followed by a space.
+                    Diagnostic(DescriptorNotFollowed).WithLocation(0),
+
+                    // /0/Test0.cs(7,17): warning SA1008: Opening parenthesis should be preceded by a space.
+                    Diagnostic(DescriptorPreceded).WithLocation(1),
+
+                    // /0/Test0.cs(8,18): warning SA1008: Opening parenthesis should not be followed by a space.
+                    Diagnostic(DescriptorNotFollowed).WithLocation(2),
+                },
+                TestCode = testCode,
+                FixedCode = fixedCode,
+            }.RunAsync(CancellationToken.None).ConfigureAwait(false);
+        }
     }
 }
diff --git a/StyleCop.Analyzers/StyleCop.Analyzers/Lightup/SyntaxKindEx.cs b/StyleCop.Analyzers/StyleCop.Analyzers/Lightup/SyntaxKindEx.cs
index 7c691a59f..d07e72561 100644
--- a/StyleCop.Analyzers/StyleCop.Analyzers/Lightup/SyntaxKindEx.cs
+++ b/StyleCop.Analyzers/StyleCop.Analyzers/Lightup/SyntaxKindEx.cs
@@ -44,6 +44,7 @@ internal static class SyntaxKindEx
         public const SyntaxKind SwitchExpression = (SyntaxKind)9025;
         public const SyntaxKind SwitchExpressionArm = (SyntaxKind)9026;
         public const SyntaxKind VarPattern = (SyntaxKind)9027;
+        public const SyntaxKind ParenthesizedPattern = (SyntaxKind)9028;
         public const SyntaxKind DeclarationExpression = (SyntaxKind)9040;
         public const SyntaxKind RefExpression = (SyntaxKind)9050;
         public const SyntaxKind RefType = (SyntaxKind)9051;
diff --git a/StyleCop.Analyzers/StyleCop.Analyzers/SpacingRules/SA1008OpeningParenthesisMustBeSpacedCorrectly.cs b/StyleCop.Analyzers/StyleCop.Analyzers/SpacingRules/SA1008OpeningParenthesisMustBeSpacedCorrectly.cs
index 34e8fafb9..6f8220da2 100644
--- a/StyleCop.Analyzers/StyleCop.Analyzers/SpacingRules/SA1008OpeningParenthesisMustBeSpacedCorrectly.cs
+++ b/StyleCop.Analyzers/StyleCop.Analyzers/SpacingRules/SA1008OpeningParenthesisMustBeSpacedCorrectly.cs
@@ -189,6 +189,11 @@ private static void HandleOpenParenToken(SyntaxTreeAnalysisContext context, Synt
                     || prevToken.IsKind(SyntaxKind.CommaToken);
                 break;
 
+            case SyntaxKindEx.ParenthesizedPattern:
+                var partOfCastExpression = prevToken.IsKind(SyntaxKind.CloseParenToken) && prevToken.Parent.IsKind(SyntaxKind.CastExpression);
+                haveLeadingSpace = !partOfCastExpression;
+                break;
+
             case SyntaxKind.ArgumentList:
             case SyntaxKind.AttributeArgumentList:
             case SyntaxKind.CheckedExpression:
@@ -216,7 +221,7 @@ private static void HandleOpenParenToken(SyntaxTreeAnalysisContext context, Synt
 
                 partOfUnaryExpression = prevToken.Parent is PrefixUnaryExpressionSyntax;
                 startOfIndexer = prevToken.IsKind(SyntaxKind.OpenBracketToken);
-                var partOfCastExpression = prevToken.IsKind(SyntaxKind.CloseParenToken) && prevToken.Parent.IsKind(SyntaxKind.CastExpression);
+                partOfCastExpression = prevToken.IsKind(SyntaxKind.CloseParenToken) && prevToken.Parent.IsKind(SyntaxKind.CastExpression);
 
                 haveLeadingSpace = !partOfUnaryExpression && !startOfIndexer && !partOfCastExpression;
                 break;