For SA1137, first in line means whitespace only

Author: sharwell

StyleCop.Analyzers/StyleCop.Analyzers.Test/ReadabilityRules/SA1137UnitTests.cs

@@ -1424,6 +1424,24 @@ void MethodName()
             await this.VerifyCSharpFixAsync(testCode, fixedCode, cancellationToken: CancellationToken.None).ConfigureAwait(false);
         }
 
+        [Fact]
+        public async Task TestLeadingCommentAsync()
+        {
+            string testCode = @"
+using System.Collections.Generic;
+class ClassName
+{
+    void MethodName()
+    {
+        /* var x = */ new List<string>();
+        var y = new List<string>();
+    }
+}
+";
+
+            await this.VerifyCSharpDiagnosticAsync(testCode, EmptyDiagnosticResults, CancellationToken.None).ConfigureAwait(false);
+        }
+
         [Fact]
         public async Task TestSwitchStatementAsync()
         {

StyleCop.Analyzers/StyleCop.Analyzers/Helpers/TokenHelper.cs

@@ -15,18 +15,44 @@ internal static class TokenHelper
         /// Gets a value indicating whether the <paramref name="token"/> is first in line.
         /// </summary>
         /// <param name="token">The token to process.</param>
-        /// <returns>true if token is first in line, otherwise false.</returns>
-        internal static bool IsFirstInLine(this SyntaxToken token)
+        /// <param name="allowNonWhitespaceTrivia"><see langword="true"/> to consider the token first-in-line even when
+        /// non-whitespace trivia precedes the token; otherwise, <see langword="false"/> to only consider tokens first
+        /// in line if they are preceded solely by whitespace.</param>
+        /// <returns>
+        /// <see langword="true"/> if <paramref name="token"/> is first in line; otherwise, <see langword="false"/>.
+        /// </returns>
+        internal static bool IsFirstInLine(this SyntaxToken token, bool allowNonWhitespaceTrivia = true)
         {
             var fullLineSpan = token.SyntaxTree.GetLineSpan(token.FullSpan);
 
+            bool firstInLine;
             if (token.SyntaxTree == null || fullLineSpan.StartLinePosition.Character == 0)
             {
-                return true;
+                firstInLine = true;
+            }
+            else
+            {
+                var tokenLineSpan = token.SyntaxTree.GetLineSpan(token.Span);
+                firstInLine = tokenLineSpan.StartLinePosition.Line != fullLineSpan.StartLinePosition.Line;
             }
 
-            var tokenLineSpan = token.SyntaxTree.GetLineSpan(token.Span);
-            return tokenLineSpan.StartLinePosition.Line != fullLineSpan.StartLinePosition.Line;
+            if (firstInLine && !allowNonWhitespaceTrivia)
+            {
+                foreach (var trivia in token.LeadingTrivia.Reverse())
+                {
+                    if (!trivia.IsKind(SyntaxKind.WhitespaceTrivia))
+                    {
+                        if (!trivia.HasBuiltinEndLine())
+                        {
+                            firstInLine = false;
+                        }
+
+                        break;
+                    }
+                }
+            }
+
+            return firstInLine;
         }
 
         /// <summary>

StyleCop.Analyzers/StyleCop.Analyzers/ReadabilityRules/SA1137ElementsShouldHaveTheSameIndentation.cs

@@ -360,7 +360,7 @@ private static void CheckElements<T>(SyntaxNodeAnalysisContext context, Immutabl
                 element =>
                 {
                     SyntaxToken firstToken = GetFirstTokenForAnalysis(element);
-                    return firstToken.IsMissingOrDefault() || !firstToken.IsFirstInLine();
+                    return firstToken.IsMissingOrDefault() || !firstToken.IsFirstInLine(allowNonWhitespaceTrivia: false);
                 });
 
             if (elements.Count < 2)