Filter CSS024 when caused by C# code in an attribute

src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/Diagnostics/CSSErrorCodes.cs

@@ -9,6 +9,7 @@ internal static class CSSErrorCodes
     public const string UnrecognizedBlockType = "CSS002";
     public const string MissingClassNameAfterDot = "CSS008";
     public const string MissingOpeningBrace = "CSS023";
+    public const string MissingPropertyName = "CSS024";
     public const string MissingPropertyValue = "CSS025";
     public const string MissingSelectorAfterCombinator = "CSS029";
     public const string MissingSelectorBeforeCombinatorCode = "CSS031";

src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/Diagnostics/RazorTranslateDiagnosticsService.cs

@@ -22,7 +22,6 @@
 namespace Microsoft.CodeAnalysis.Razor.Diagnostics;
 
 using RazorDiagnosticFactory = AspNetCore.Razor.Language.RazorDiagnosticFactory;
-using RazorSyntaxNodeOrToken = AspNetCore.Razor.Language.Syntax.SyntaxNodeOrToken;
 using SyntaxNode = AspNetCore.Razor.Language.Syntax.SyntaxNode;
 
 /// <summary>
@@ -99,7 +98,7 @@ private static LspDiagnostic[] FilterHTMLDiagnostics(
         var syntaxTree = codeDocument.GetRequiredSyntaxTree();
         var sourceText = codeDocument.Source.Text;
 
-        var processedAttributes = new Dictionary<TextSpan, bool>();
+        using var _ = DictionaryPool<TextSpan, bool>.GetPooledObject(out var processedAttributes);
 
         var filteredDiagnostics = unmappedDiagnostics
             .Where(d =>
@@ -244,6 +243,7 @@ private static bool ShouldFilterHtmlDiagnosticBasedOnErrorCode(LspDiagnostic dia
             CSSErrorCodes.MissingOpeningBrace or
             CSSErrorCodes.MissingClassNameAfterDot or
             CSSErrorCodes.MissingSelectorAfterCombinator or
+            CSSErrorCodes.MissingPropertyName or
             CSSErrorCodes.MissingPropertyValue or
             CSSErrorCodes.MissingSelectorBeforeCombinatorCode => IsAtCSharpTransitionInStyleBlock(diagnostic, sourceText, syntaxTree),
             HtmlErrorCodes.UnexpectedEndTagErrorCode => IsHtmlWithBangAndMatchingTags(diagnostic, sourceText, syntaxTree),
@@ -428,17 +428,16 @@ private static bool InAttributeContainingCSharp(
             return false;
         }
 
-        var markupAttributeNode = owner.FirstAncestorOrSelf<RazorSyntaxNode>(static n =>
-            n is MarkupAttributeBlockSyntax ||
-            n is MarkupTagHelperAttributeSyntax ||
-            n is MarkupMiscAttributeContentSyntax);
+        var markupAttributeValue = owner.FirstAncestorOrSelf<RazorSyntaxNode>(static n =>
+            (n.Parent is MarkupAttributeBlockSyntax block && n == block.Value) ||
+            n is MarkupTagHelperAttributeValueSyntax or MarkupMiscAttributeContentSyntax);
 
-        if (markupAttributeNode is not null)
+        if (markupAttributeValue is not null)
         {
-            if (!processedAttributes.TryGetValue(markupAttributeNode.Span, out var doesAttributeContainNonMarkup))
+            if (!processedAttributes.TryGetValue(markupAttributeValue.Span, out var doesAttributeContainNonMarkup))
             {
-                doesAttributeContainNonMarkup = CheckIfAttributeContainsNonMarkupNodes(markupAttributeNode);
-                processedAttributes.Add(markupAttributeNode.Span, doesAttributeContainNonMarkup);
+                doesAttributeContainNonMarkup = CheckIfAttributeContainsNonMarkupNodes(markupAttributeValue);
+                processedAttributes.Add(markupAttributeValue.Span, doesAttributeContainNonMarkup);
             }
 
             return doesAttributeContainNonMarkup;
@@ -448,16 +447,16 @@ n is MarkupTagHelperAttributeSyntax ||
 
         static bool CheckIfAttributeContainsNonMarkupNodes(RazorSyntaxNode attributeNode)
         {
-            // Only allow markup, generic & (non-razor comment) token nodes
-            var containsNonMarkupNodes = attributeNode.DescendantNodesAndTokens().Any(IsNotMarkupNodeOrCommentToken);
-
-            return containsNonMarkupNodes;
+            return attributeNode.DescendantNodes().Any(IsNotMarkupOrCommentNode);
         }
 
-        static bool IsNotMarkupNodeOrCommentToken(RazorSyntaxNodeOrToken nodeOrToken)
+        static bool IsNotMarkupOrCommentNode(SyntaxNode node)
         {
-            return !(nodeOrToken.IsToken && nodeOrToken.AsToken().Kind == SyntaxKind.RazorCommentTransition) &&
-                   !(nodeOrToken.IsNode && nodeOrToken.AsNode() is MarkupBlockSyntax or MarkupSyntaxNode or GenericBlockSyntax);
+            return !(node is
+                MarkupBlockSyntax or
+                MarkupSyntaxNode or
+                GenericBlockSyntax or
+                RazorCommentBlockSyntax);
         }
     }
 

src/Razor/test/Microsoft.VisualStudio.LanguageServices.Razor.Test/Cohost/CohostDocumentPullDiagnosticsTest.cs

@@ -375,6 +375,40 @@ public Task FilterPropertyValueInCss()
             }]);
     }
 
+    [Fact]
+    public Task FilterPropertyNameInCss()
+    {
+        TestCode input = """
+            <div style="{|CSS024:/|}****/"></div>
+            <div style="@(someBool ? "width: 100%" : "width: 50%")">
+
+            </div>
+
+            @code
+            {
+                private bool someBool = false;
+            }
+            """;
+
+        return VerifyDiagnosticsAsync(input,
+            htmlResponse: [new VSInternalDiagnosticReport
+            {
+                Diagnostics =
+                [
+                    new LspDiagnostic
+                    {
+                        Code = CSSErrorCodes.MissingPropertyName,
+                        Range = SourceText.From(input.Text).GetRange(new TextSpan(input.Text.IndexOf("/"), 1))
+                    },
+                    new LspDiagnostic
+                    {
+                        Code = CSSErrorCodes.MissingPropertyName,
+                        Range = SourceText.From(input.Text).GetRange(new TextSpan(input.Text.IndexOf("@"), 1))
+                    },
+                ]
+            }]);
+    }
+
     [Fact]
     public Task CombinedAndNestedDiagnostics()
         => VerifyDiagnosticsAsync("""