fixed unit test failure due to behavior change of AD001 description.

src/Compilers/Core/CodeAnalysisTest/Diagnostics/SuppressMessageAttributeTests.cs

@@ -1131,7 +1131,7 @@ End Class
         }
 
         [Fact]
-        public async Task SuppressDuplicateAnalyzerExceptionDiagnostics()
+        public async Task AnalyzerExceptionDiagnosticsWithDifferentContext()
         {
             var exceptionDiagnostics = new HashSet<Diagnostic>();
 
@@ -1149,13 +1149,15 @@ public class C2
                 new[] { new ThrowExceptionForEachNamedTypeAnalyzer() },
                 onAnalyzerException: (ex, a, d) => exceptionDiagnostics.Add(d));
 
-            exceptionDiagnostics.Verify(
-                Diagnostic("AD0001", null)
+            var diagnostic = Diagnostic("AD0001", null)
                     .WithArguments(
                         "Microsoft.CodeAnalysis.UnitTests.Diagnostics.SuppressMessageAttributeTests+ThrowExceptionForEachNamedTypeAnalyzer",
                         "System.Exception",
                         "ThrowExceptionAnalyzer exception")
-                    .WithLocation(1, 1));
+                    .WithLocation(1, 1);
+
+            // expect 3 different diagnostics with 3 different contexts.
+            exceptionDiagnostics.Verify(diagnostic, diagnostic, diagnostic);
         }
 
         #endregion

src/Compilers/Core/Portable/DiagnosticAnalyzer/AnalysisContextInfo.cs

@@ -91,29 +91,39 @@ public string GetContext()
 
             if (_node != null)
             {
+                var text = _tree?.GetText();
+                var lineSpan = text?.Lines?.GetLinePositionSpan(_node.Span);
+
                 // can't use Kind since that is language specific. instead will output typename.
-                sb.AppendLine($"{nameof(SyntaxNode)}: \"{GetValueText(_node)}\" {_node.GetType().Name}@{_node.Span.ToString()}");
+                sb.AppendLine($"{nameof(SyntaxNode)}: {GetFlattenedNodeText(_node)} [{_node.GetType().Name}]@{_node.Span.ToString()} {(lineSpan.HasValue ? lineSpan.Value.ToString() : string.Empty)}");
             }
 
             return sb.ToString();
         }
 
-        private string GetValueText(SyntaxNode node)
+        private string GetFlattenedNodeText(SyntaxNode node)
         {
             const int cutoff = 30;
 
-            if (node.Span.Length < cutoff)
+            var lastEnd = node.Span.Start;
+            var sb = new StringBuilder();
+            foreach (var token in node.DescendantTokens(descendIntoTrivia: false))
             {
-                return RemoveNewLines(node.ToString());
+                if (token.Span.Start - lastEnd > 0)
+                {
+                    sb.Append(" ");
                 }
 
-            // get actual text without creating texts for all sub nodes.
-            return RemoveNewLines(node.GetText().ToString(new TextSpan(node.Span.Start - node.FullSpan.Start, cutoff))) + " ...";
-        }
+                sb.Append(token.ToString());
+                lastEnd = token.Span.End;
 
-        private string RemoveNewLines(string text)
+                if (sb.Length > cutoff)
                 {
-            return text.Replace(Environment.NewLine, @"\r\n");
+                    break;
+                }
+            }
+
+            return sb.ToString() + (sb.Length > cutoff ? " ..." : string.Empty);
         }
     }
 }