Merge pull request #34315 from JoeRobich/filter-additive-classifications

Filter out additive classifications in EditorClassifier

src/EditorFeatures/Core/Implementation/Classification/EditorClassifier.cs

@@ -72,6 +72,14 @@ internal static class EditorClassifier
                 await delegationService.AddSemanticClassificationsAsync(
                     classificationService, document, widenedSpan, semanticSpans, cancellationToken).ConfigureAwait(false);
 
+                // MergeClassifiedSpans will ultimately filter multiple classifications for the same
+                // span down to one. We know that additive classifications are there just to 
+                // provide additional information about the true classification. We will remove
+                // additive ClassifiedSpans until we have support for additive classifications
+                // in classified spans. https://github.com/dotnet/roslyn/issues/32770
+                RemoveAdditiveSpans(syntaxSpans);
+                RemoveAdditiveSpans(semanticSpans);
+
                 var classifiedSpans = MergeClassifiedSpans(
                     syntaxSpans, semanticSpans, widenedSpan, sourceText);
                 return classifiedSpans;
@@ -83,6 +91,18 @@ internal static class EditorClassifier
             }
         }
 
+        private static void RemoveAdditiveSpans(List<ClassifiedSpan> spans)
+        {
+            for (var i = spans.Count - 1; i >= 0; i--)
+            {
+                var span = spans[i];
+                if (ClassificationTypeNames.AdditiveTypeNames.Contains(span.ClassificationType))
+                {
+                    spans.RemoveAt(i);
+                }
+            }
+        }
+
         private static ImmutableArray<ClassifiedSpan> MergeClassifiedSpans(
             List<ClassifiedSpan> syntaxSpans, List<ClassifiedSpan> semanticSpans,
             TextSpan widenedSpan, SourceText sourceText)