nits and test fixes

Author: marcarro

src/Razor/src/Microsoft.AspNetCore.Razor.LanguageServer/CodeActions/Razor/ExtractToNewComponentCodeActionProvider.cs

@@ -190,10 +190,7 @@ private static void ProcessMultiPointSelection(MarkupElementSyntax startElementN
         }
     }
 
-    private static bool IsMultiPointSelection(Range range)
-    {
-        return range.Start != range.End;
-    }
+    private static bool IsMultiPointSelection(Range range) => range.Start != range.End;
 
     private static SourceLocation? GetEndLocation(Position selectionEnd, RazorCodeDocument codeDocument, ILogger logger)
     {
@@ -234,14 +231,14 @@ private static (SyntaxNode? Start, SyntaxNode? End) FindContainingSiblingPair(Sy
             if (startContainingNode == null && childSpan.Contains(startSpan))
             {
                 startContainingNode = child;
-                if (endContainingNode != null)
+                if (endContainingNode is not null)
                     break; // Exit if we've found both
             }
 
             if (childSpan.Contains(endSpan))
             {
                 endContainingNode = child;
-                if (startContainingNode != null)
+                if (startContainingNode is not null)
                     break; // Exit if we've found both
             }
         }
@@ -253,7 +250,7 @@ private static (SyntaxNode? Start, SyntaxNode? End) FindContainingSiblingPair(Sy
     {
         var current = node1;
 
-        while (current.Kind == SyntaxKind.MarkupElement && current != null)
+        while (current.Kind == SyntaxKind.MarkupElement && current is not null)
         {
             if (current.Span.Contains(node2.Span))
             {

src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/CodeActions/Razor/ExtractToNewComponentCodeActionProviderTest.cs

@@ -194,7 +194,7 @@ public async Task Handle_ValidElementSelection_ReturnsNotNull(string markupEleme
         var commandOrCodeActionContainer = await provider.ProvideAsync(context, default);
 
         // Assert
-        Assert.NotNull(commandOrCodeActionContainer);
+        Assert.NotEmpty(commandOrCodeActionContainer);
     }
 
     private static RazorCodeActionContext CreateRazorCodeActionContext(VSCodeActionParams request, SourceLocation location, string filePath, string text, bool supportsFileCreation = true)