Fix analyzer RCS1262 (#1339)

Author: josefpihrt

ChangeLog.md

@@ -24,6 +24,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - [TestFramework] Bump `xunit.assert` to `2.6.2` ([PR](https://github.com/dotnet/roslynator/pull/1332))
 - Bump Roslyn to 4.7.0 ([PR](https://github.com/dotnet/roslynator/pull/1325))
 
+### Fixed
+
+- Fix analyzer [RCS1262](https://josefpihrt.github.io/docs/roslynator/analyzers/RCS1262) ([PR](https://github.com/dotnet/roslynator/pull/1339))
+
 ## [4.7.0] - 2023-12-03
 
 ### Added

src/Analyzers.CodeFixes/CSharp/CodeFixes/UnnecessaryRawStringLiteralCodeFixProvider.cs

@@ -2,6 +2,7 @@
 
 using System.Collections.Immutable;
 using System.Composition;
+using System.Linq;
 using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.CodeAnalysis;
@@ -71,9 +72,26 @@ private static Task<Document> RefactorAsync(
         InterpolatedStringExpressionSyntax interpolatedString,
         CancellationToken cancellationToken)
     {
-        string newText = interpolatedString.ToString();
-        int startIndex = interpolatedString.StringStartToken.Text.Length;
-        newText = "$\"" + newText.Substring(startIndex, newText.Length - startIndex - interpolatedString.StringEndToken.Text.Length) + "\"";
+        InterpolatedStringExpressionSyntax newInterpolatedString = interpolatedString.ReplaceTokens(
+            interpolatedString
+                .Contents
+                .OfType<InterpolationSyntax>()
+                .SelectMany(interpolation => new SyntaxToken[] { interpolation.OpenBraceToken, interpolation.CloseBraceToken }),
+            (token, _) =>
+            {
+                if (token.IsKind(SyntaxKind.OpenBraceToken))
+                {
+                    return SyntaxFactory.Token(SyntaxKind.OpenBraceToken).WithTriviaFrom(token);
+                }
+                else
+                {
+                    return SyntaxFactory.Token(SyntaxKind.CloseBraceToken).WithTriviaFrom(token);
+                }
+            });
+
+        string text = newInterpolatedString.ToString();
+        int startIndex = newInterpolatedString.StringStartToken.Text.Length;
+        string newText = "$\"" + text.Substring(startIndex, text.Length - startIndex - newInterpolatedString.StringEndToken.Text.Length) + "\"";
 
         return document.WithTextChangeAsync(interpolatedString.Span, newText, cancellationToken);
     }

src/Analyzers/CSharp/Analysis/UnnecessaryRawStringLiteralAnalyzer.cs

@@ -48,7 +48,7 @@ private static void AnalyzeStringLiteralExpression(SyntaxNodeAnalysisContext con
 
         string text = info.Text;
 
-        if (ContainsBackSlashQuote(text, info.QuoteCount, text.Length - (info.QuoteCount * 2)))
+        if (ContainsBackSlashOrQuote(text, info.QuoteCount, text.Length - (info.QuoteCount * 2)))
             return;
 
         DiagnosticHelpers.ReportDiagnostic(
@@ -72,25 +72,43 @@ private static void AnalyzeInterpolatedStringExpression(SyntaxNodeAnalysisContex
             {
                 string text = interpolatedStringText.TextToken.Text;
 
-                if (ContainsBackSlashQuote(text, 0, text.Length))
+                if (ContainsBackSlashOrQuoteOrOpenBrace(text, 0, text.Length))
                     return;
             }
         }
 
+        int offset = startToken.ValueText.LastIndexOf('$') + 2;
+
         DiagnosticHelpers.ReportDiagnostic(
             context,
             DiagnosticRules.UnnecessaryRawStringLiteral,
-            Location.Create(interpolatedString.SyntaxTree, new TextSpan(startToken.SpanStart + 2, startToken.Span.Length - 2)));
+            Location.Create(interpolatedString.SyntaxTree, new TextSpan(startToken.SpanStart + offset, startToken.Span.Length - offset)));
+    }
+
+    private static bool ContainsBackSlashOrQuote(string text, int start, int length)
+    {
+        for (int pos = start; pos < start + length; pos++)
+        {
+            switch (text[pos])
+            {
+                case '\\':
+                case '"':
+                    return true;
+            }
+        }
+
+        return false;
     }
 
-    private static bool ContainsBackSlashQuote(string text, int start, int length)
+    private static bool ContainsBackSlashOrQuoteOrOpenBrace(string text, int start, int length)
     {
         for (int pos = start; pos < start + length; pos++)
         {
             switch (text[pos])
             {
                 case '\\':
                 case '"':
+                case '{':
                     return true;
             }
         }

src/Tests/Analyzers.Tests/RCS1262UnnecessaryRawStringLiteralTests.cs

@@ -58,6 +58,32 @@ void M()
 ");
     }
 
+    [Fact, Trait(Traits.Analyzer, DiagnosticIdentifiers.UnnecessaryRawStringLiteral)]
+    public async Task Test_InterpolatedString_MultipleDollarSigns()
+    {
+        await VerifyDiagnosticAndFixAsync(@"
+class C
+{
+    void M()
+    {
+        string s1 = """";
+        string s2 = """";
+        string s3 = $$$""[|""""|] {{{s1}}} foo {{{s2}}} """""";
+    }
+}
+", @"
+class C
+{
+    void M()
+    {
+        string s1 = """";
+        string s2 = """";
+        string s3 = $"" {s1} foo {s2} "";
+    }
+}
+");
+    }
+
     [Fact, Trait(Traits.Analyzer, DiagnosticIdentifiers.UnnecessaryRawStringLiteral)]
     public async Task TestNoDiagnostic_ContainsQuote()
     {
@@ -111,6 +137,21 @@ void M()
         string s = $"""""" {""""} \t """""";
     }
 }
+");
+    }
+
+    [Fact, Trait(Traits.Analyzer, DiagnosticIdentifiers.UnnecessaryRawStringLiteral)]
+    public async Task TestNoDiagnostic_MultipleDollarSigns()
+    {
+        await VerifyNoDiagnosticAsync(@"
+class C
+{
+    void M()
+    {
+        string s = string.Empty;
+        s = $$""""""{{s}}{s}"""""";
+    }
+}
 ");
     }
 }