Null annotate FirstAncestorOrSelf

src/Compiler/Microsoft.AspNetCore.Razor.Language/src/Syntax/SyntaxNode.cs

@@ -340,10 +340,11 @@ public IEnumerable<SyntaxNode> AncestorsAndSelf()
         }
     }
 
+#nullable enable
     /// <summary>
     /// Gets the first node of type TNode that matches the predicate.
     /// </summary>
-    public TNode FirstAncestorOrSelf<TNode>(Func<TNode, bool> predicate = null)
+    public TNode? FirstAncestorOrSelf<TNode>(Func<TNode, bool>? predicate = null)
         where TNode : SyntaxNode
     {
         for (var node = this; node != null; node = node.Parent)
@@ -356,6 +357,7 @@ public TNode FirstAncestorOrSelf<TNode>(Func<TNode, bool> predicate = null)
 
         return default;
     }
+#nullable disable
 
     /// <summary>
     /// Gets a list of descendant nodes in prefix document order.

src/Razor/src/Microsoft.AspNetCore.Razor.LanguageServer/Diagnostics/RazorTranslateDiagnosticsService.cs

@@ -241,7 +241,7 @@ static bool IsCSharpInStyleBlock(Diagnostic diagnostic, SourceText sourceText, R
             var element = owner.FirstAncestorOrSelf<MarkupElementSyntax>(n => n.StartTag?.Name.Content == "style");
             var csharp = owner.FirstAncestorOrSelf<CSharpCodeBlockSyntax>();
 
-            return element.Body.Any(c => c is CSharpCodeBlockSyntax) || csharp is not null;
+            return element?.Body.Any(c => c is CSharpCodeBlockSyntax) ?? false || csharp is not null;
         }
 
         // Ideally this would be solved instead by not emitting the "!" at the HTML backing file,
@@ -255,6 +255,10 @@ static bool IsAnyFilteredTooFewElementsError(Diagnostic diagnostic, SourceText s
             }
 
             var element = owner.FirstAncestorOrSelf<MarkupElementSyntax>();
+            if (element is null)
+            {
+                return false;
+            }
 
             if (element.StartTag?.Name.Content != "html")
             {
@@ -280,8 +284,8 @@ static bool IsHtmlWithBangAndMatchingTags(Diagnostic diagnostic, SourceText sour
             }
 
             var element = owner.FirstAncestorOrSelf<MarkupElementSyntax>();
-            var startNode = element.StartTag;
-            var endNode = element.EndTag;
+            var startNode = element?.StartTag;
+            var endNode = element?.EndTag;
 
             if (startNode is null || endNode is null)
             {
@@ -290,9 +294,9 @@ static bool IsHtmlWithBangAndMatchingTags(Diagnostic diagnostic, SourceText sour
             }
 
             var haveBang = startNode.Bang is not null && endNode.Bang is not null;
-            var namesEquivilant = startNode.Name.Content == endNode.Name.Content;
+            var namesEquivalent = startNode.Name.Content == endNode.Name.Content;
 
-            return haveBang && namesEquivilant;
+            return haveBang && namesEquivalent;
         }
 
         static bool IsAnyFilteredInvalidNestingError(Diagnostic diagnostic, SourceText sourceText, RazorSyntaxTree syntaxTree, ILogger logger)
@@ -334,7 +338,7 @@ static bool IsInvalidNestingFromBody(Diagnostic diagnostic, SourceText sourceTex
                 return false;
             }
 
-            return diagnostic.Message.EndsWith("cannot be nested inside element 'html'.") && body.StartTag?.Bang is not null;
+            return diagnostic.Message.EndsWith("cannot be nested inside element 'html'.") && body?.StartTag?.Bang is not null;
         }
     }
 

src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/Diagnostics/RazorTranslateDiagnosticsEndpointTest.cs

@@ -347,6 +347,45 @@ public async Task Handle_FilterDiagnostics_CSharpInsideStyleBlock()
         Assert.Empty(response.Diagnostics);
     }
 
+    [Fact]
+    public async Task Handle_FilterDiagnostics_CSharpInsideStyleBlockSpace_NotStyleTag()
+    {
+        // Arrange
+        var documentPath = new Uri("C:/path/to/document.cshtml");
+        var codeDocument = CreateCodeDocumentWithCSharpProjection(
+            "<stile> @DateTime.Now </stile>",
+            "var __o = DateTime.Now",
+            new[] {
+                new SourceMapping(
+                    new SourceSpan(4, 12),
+                    new SourceSpan(10, 12))
+            });
+        var documentContext = CreateDocumentContext(documentPath, codeDocument);
+        var diagnosticsService = new RazorTranslateDiagnosticsService(_mappingService, LoggerFactory);
+        var diagnosticsEndpoint = new RazorTranslateDiagnosticsEndpoint(diagnosticsService, LoggerFactory);
+        var request = new RazorDiagnosticsParams()
+        {
+            Kind = RazorLanguageKind.Html,
+            Diagnostics = new[] {
+                new VSDiagnostic() {
+                    Range = new Range { Start = new Position(0, 7),End =  new Position(0, 7) },
+                    Code = CSSErrorCodes.MissingSelectorBeforeCombinatorCode,
+                    Severity = DiagnosticSeverity.Warning
+                }
+            },
+            RazorDocumentUri = documentPath,
+        };
+        var expectedRange = new Range { Start = new Position(0, 8), End = new Position(0, 15) };
+        var requestContext = CreateRazorRequestContext(documentContext);
+
+        // Act
+        var response = await Task.Run(() => diagnosticsEndpoint.HandleRequestAsync(request, requestContext, default));
+
+        // Assert
+        Assert.NotNull(response.Diagnostics);
+        Assert.Equal(CSSErrorCodes.MissingSelectorBeforeCombinatorCode, response.Diagnostics![0].Code);
+    }
+
     [Fact]
     public async Task Handle_FilterDiagnostics_CSharpWarning()
     {