Do not report zero length diagnostic (dotnet#1590)

cbersch · Dec 4, 2024 · 96dfb34 · 96dfb34
1 parent f7ed06f
commit 96dfb34
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diff --git a/ChangeLog.md b/ChangeLog.md
@@ -16,6 +16,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Changed
 
 - Update whitespace formatting rules ([PR](https://github.com/dotnet/roslynator/pull/1576))
+- Ensure that diagnostics are not reported with zero length ([PR](https://github.com/dotnet/roslynator/pull/1590))
 
 ## [4.12.9] - 2024-10-25
 

diff --git a/src/Common/CSharp/TriviaBlock.cs b/src/Common/CSharp/TriviaBlock.cs
@@ -2,6 +2,7 @@
 
 using System;
 using System.Diagnostics;
+using System.Linq;
 using Microsoft.CodeAnalysis;
 using Microsoft.CodeAnalysis.CSharp;
 using Microsoft.CodeAnalysis.Text;
@@ -49,9 +50,50 @@ private TriviaBlock(
 
     public Location GetLocation()
     {
+        TextSpan span;
+        if (Kind == TriviaBlockKind.BlankLine)
+        {
+            TriviaBlockReader reader = CreateReader();
+            reader.ReadWhile(trivia => !trivia.IsEndOfLineTrivia());
+            reader.ReadWhile(trivia => !trivia.IsEndOfLineTrivia());
+            span = reader.Current.Span;
+        }
+        else
+        {
+            SyntaxTriviaList triviaList = (!First.IsKind(SyntaxKind.None))
+                ? First.GetTrailingTrivia()
+                : Second.GetLeadingTrivia();
+
+            span = triviaList.LastOrDefault(f => f.IsEndOfLineTrivia()).Span;
+
+            if (span.Length == 0)
+            {
+                SyntaxTrivia trivia = triviaList.LastOrDefault();
+
+                if (trivia.IsKind(SyntaxKind.WhitespaceTrivia))
+                    span = trivia.Span;
+            }
+
+            if (span.Length == 0)
+            {
+                if (Second.Span.Length > 0)
+                {
+                    span = new TextSpan(Second.SpanStart, 1);
+                }
+                else if (First.Span.Length > 0)
+                {
+                    span = new TextSpan(First.Span.End - 1, 1);
+                }
+                else
+                {
+                    span = new TextSpan(Position, 0);
+                }
+            }
+        }
+
         return Location.Create(
             (!First.IsKind(SyntaxKind.None)) ? First.SyntaxTree : Second.SyntaxTree,
-            new TextSpan(Position, 0));
+            span);
     }
 
     public TriviaBlockReader CreateReader()
@@ -125,7 +167,7 @@ private static TriviaBlock Analyze(SyntaxNodeOrToken first, SyntaxNodeOrToken se
 
         while (true)
         {
-            SyntaxTrivia trivia = reader.ReadLine();
+            SyntaxTrivia trivia = reader.ReadWhile(trivia => trivia.IsWhitespaceTrivia());
 
             if (trivia.IsDirective)
                 return default;
@@ -169,7 +211,7 @@ private static TriviaBlock Analyze(SyntaxNodeOrToken first, SyntaxNodeOrToken se
                 }
                 case SyntaxKind.SingleLineCommentTrivia:
                 {
-                    if (!reader.Read(SyntaxKind.EndOfLineTrivia))
+                    if (!reader.TryRead(SyntaxKind.EndOfLineTrivia))
                         return default;
 
                     if (first.IsKind(SyntaxKind.None))

diff --git a/src/Common/CSharp/TriviaBlockReader.cs b/src/Common/CSharp/TriviaBlockReader.cs
@@ -1,5 +1,6 @@
 // Copyright (c) .NET Foundation and Contributors. Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
+using System;
 using System.Diagnostics;
 using Microsoft.CodeAnalysis;
 using Microsoft.CodeAnalysis.CSharp;
@@ -32,11 +33,11 @@ internal TriviaBlockReader(SyntaxNodeOrToken first, SyntaxNodeOrToken second)
 
     public readonly SyntaxTrivia Current => _list[_index];
 
-    public SyntaxTrivia ReadLine()
+    public SyntaxTrivia ReadWhile(Func<SyntaxTrivia, bool> predicate)
     {
         while (MoveNext())
         {
-            if (!Current.IsWhitespaceTrivia())
+            if (!predicate(Current))
                 return Current;
         }
 
@@ -46,17 +47,12 @@ public SyntaxTrivia ReadLine()
     public void ReadTo(int position)
     {
         while (MoveNext()
-            && Current.SpanStart != position)
+            && Current.SpanStart < position)
         {
         }
     }
 
-    public bool ReadWhiteSpaceTrivia()
-    {
-        return Read(SyntaxKind.WhitespaceTrivia);
-    }
-
-    public bool Read(SyntaxKind kind)
+    public bool TryRead(SyntaxKind kind)
     {
         if (Peek().IsKind(kind))
         {
@@ -67,7 +63,7 @@ public bool Read(SyntaxKind kind)
         return false;
     }
 
-    public void ReadWhiteSpace()
+    public void ReadWhiteSpaces()
     {
         while (Peek().IsWhitespaceOrEndOfLineTrivia())
             MoveNext();
@@ -100,7 +96,7 @@ public void ReadBlankLines()
         }
     }
 
-    public readonly SyntaxTrivia Peek(int offset = 0)
+    private readonly SyntaxTrivia Peek(int offset = 0)
     {
         offset++;
         if (_index + offset < _list.Count)

diff --git a/src/Tests/Formatting.Analyzers.Tests/RCS0001AddBlankLineAfterEmbeddedStatementTests.cs b/src/Tests/Formatting.Analyzers.Tests/RCS0001AddBlankLineAfterEmbeddedStatementTests.cs
@@ -23,8 +23,8 @@ void M()
         bool f = false;
 
         if (f)
-            M();[||]
-        M();
+            M();[|
+|]        M();
     }
 }
 ", @"
@@ -56,8 +56,8 @@ void M()
         if (f)
             M();
         else if (f)
-            M();[||]
-        M();
+            M();[|
+|]        M();
     }
 }
 ", @"
@@ -91,8 +91,8 @@ void M()
         if (f)
             M();
         else
-            M();[||]
-        M();
+            M();[|
+|]        M();
     }
 }
 ", @"
@@ -127,8 +127,8 @@ void M()
         var items = new List<object>();
 
         foreach (object item in items)
-            M();[||]
-        M();
+            M();[|
+|]        M();
     }
 }
 ", @"
@@ -164,8 +164,8 @@ void M()
         var items = new List<object>();
 
         foreach ((int a, int b) in new[] { (0, 0) })
-            M();[||]
-        M();
+            M();[|
+|]        M();
     }
 }
 ", @"
@@ -201,8 +201,8 @@ void M()
         var items = new List<object>();
 
         for (int i = 0; i < items.Count; i++)
-            M();[||]
-        M();
+            M();[|
+|]        M();
     }
 }
 ", @"
@@ -237,8 +237,8 @@ void M()
         bool f = false;
 
         using ((IDisposable)null)
-            M();[||]
-        M();
+            M();[|
+|]        M();
     }
 }
 ", @"
@@ -270,8 +270,8 @@ void M()
         bool f = false;
 
         while (f)
-            M();[||]
-        M();
+            M();[|
+|]        M();
     }
 }
 ", @"
@@ -301,8 +301,8 @@ void M()
         bool f = false;
 
         lock (null)
-            M();[||]
-        M();
+            M();[|
+|]        M();
     }
 }
 ", @"
@@ -334,8 +334,8 @@ void M()
         unsafe
         {
             fixed (char* p = "")
-                M();[||]
-            M();
+                M();[|
+|]            M();
         }
     }
 }
@@ -373,8 +373,8 @@ void M()
         {
             case null:
                 if (f)
-                    M();[||]
-                break;
+                    M();[|
+|]                break;
         }
     }
 }

diff --git a/src/Tests/Formatting.Analyzers.Tests/RCS0003AddBlankLineAfterUsingDirectiveListTests.cs b/src/Tests/Formatting.Analyzers.Tests/RCS0003AddBlankLineAfterUsingDirectiveListTests.cs
@@ -22,8 +22,8 @@ public async Task Test_CompilationUnit_Comment_After()
     {
         await VerifyDiagnosticAndFixAsync(@"
 using System;
-using System.Linq;[||]
-// x
+using System.Linq;[|
+|]// x
 namespace N
 {
 }
@@ -43,8 +43,8 @@ public async Task Test_CompilationUnit_DocumentationComment_After()
     {
         await VerifyDiagnosticAndFixAsync(@"
 using System;
-using System.Linq;[||]
-/// <summary></summary>
+using System.Linq;[|
+|]/// <summary></summary>
 namespace N
 {
 }
@@ -64,8 +64,8 @@ public async Task Test_CompilationUnit_AssemblyAttribute_After()
     {
         await VerifyDiagnosticAndFixAsync(@"
 using System;
-using System.Linq;[||]
-[assembly: System.Diagnostics.CodeAnalysis.SuppressMessage(null, null)]
+using System.Linq;[|
+|][assembly: System.Diagnostics.CodeAnalysis.SuppressMessage(null, null)]
 
 namespace N
 {
@@ -87,8 +87,8 @@ public async Task Test_CompilationUnit_CommentAndAssemblyAttribute_After()
     {
         await VerifyDiagnosticAndFixAsync(@"
 using System;
-using System.Linq; // x[||]
-[assembly: System.Diagnostics.CodeAnalysis.SuppressMessage(null, null)]
+using System.Linq; // x[|
+|][assembly: System.Diagnostics.CodeAnalysis.SuppressMessage(null, null)]
 
 namespace N
 {
@@ -110,8 +110,8 @@ public async Task Test_CompilationUnit_NamespaceDeclaration_After()
     {
         await VerifyDiagnosticAndFixAsync(@"
 using System;
-using System.Linq;[||]
-namespace N
+using System.Linq;[|
+|]namespace N
 {
 }
 ", @"
@@ -131,8 +131,8 @@ await VerifyDiagnosticAndFixAsync(@"
 namespace N
 {
     using System;
-    using System.Linq;[||]
-    // x
+    using System.Linq;[|
+|]    // x
     class C
     {
     }
@@ -158,8 +158,8 @@ await VerifyDiagnosticAndFixAsync(@"
 namespace N
 {
     using System;
-    using System.Linq;[||]
-    /// <summary></summary>
+    using System.Linq;[|
+|]    /// <summary></summary>
     class C
     {
     }
@@ -185,8 +185,8 @@ await VerifyDiagnosticAndFixAsync(@"
 namespace N
 {
     using System;
-    using System.Linq;[||]
-    class C
+    using System.Linq;[|
+|]    class C
     {
     }
 }

diff --git a/src/Tests/Formatting.Analyzers.Tests/RCS0006AddEmptyLineBeforeUsingDirectiveListTests.cs b/src/Tests/Formatting.Analyzers.Tests/RCS0006AddEmptyLineBeforeUsingDirectiveListTests.cs
@@ -20,8 +20,8 @@ public override CSharpTestOptions Options
     [Fact, Trait(Traits.Analyzer, DiagnosticIdentifiers.AddBlankLineBeforeUsingDirectiveList)]
     public async Task Test_Comment_Before()
     {
-        await VerifyDiagnosticAndFixAsync(@"// x[||]
-using System;
+        await VerifyDiagnosticAndFixAsync(@"// x[|
+|]using System;
 using System.Linq;
 
 namespace N
@@ -42,8 +42,8 @@ namespace N
     public async Task Test_Comments_Before()
     {
         await VerifyDiagnosticAndFixAsync(@"// x
-// x[||]
-using System;
+// x[|
+|]using System;
 
 class C;
 ", @"// x
@@ -59,8 +59,8 @@ class C;
     public async Task Test_CommentAndExternAlias_Before()
     {
         await VerifyDiagnosticAndFixAsync(@"
-extern alias x;[||]
-using System;
+extern alias x;[|
+|]using System;
 using System.Linq;
 
 namespace N
@@ -82,8 +82,8 @@ namespace N
     public async Task Test_Comment_ExternAliasAndComment_Before()
     {
         await VerifyDiagnosticAndFixAsync(@"
-extern alias x; // x[||]
-using System;
+extern alias x; // x[|
+|]using System;
 using System.Linq;
 
 namespace N