Add support for IDE0040 accessibility modifier code actions

Co-authored-by: davidwengier <754264+davidwengier@users.noreply.github.com>

Author: Copilot

src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/CodeActions/CSharp/CSharpCodeActionProvider.cs

@@ -37,6 +37,7 @@ internal class CSharpCodeActionProvider(LanguageServerFeatureOptions languageSer
         RazorPredefinedCodeRefactoringProviderNames.ConvertConcatenationToInterpolatedString,
         RazorPredefinedCodeRefactoringProviderNames.ConvertPlaceholderToInterpolatedString,
         RazorPredefinedCodeRefactoringProviderNames.ConvertToInterpolatedString,
+        "AddAccessibilityModifiers", // IDE0040: Accessibility modifiers required
         RazorPredefinedCodeFixProviderNames.ImplementAbstractClass,
         RazorPredefinedCodeFixProviderNames.ImplementInterface,
         RazorPredefinedCodeFixProviderNames.RemoveUnusedVariable,

src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/CodeActions/CSharp/CSharpCodeActionProviderTest.cs

@@ -298,6 +298,42 @@ public async Task ProvideAsync_ImplicitExpression_ReturnsProvidedCodeAction()
         Assert.Equal(expectedNames, providedNames);
     }
 
+    [Fact]
+    public async Task ProvideAsync_AddAccessibilityModifiers_ReturnsProvidedCodeAction()
+    {
+        // Arrange
+        var documentPath = "c:/Test.razor";
+        var contents = "@code { $$void Method() { } }";
+        TestFileMarkupParser.GetPosition(contents, out contents, out var cursorPosition);
+
+        var request = new VSCodeActionParams()
+        {
+            TextDocument = new VSTextDocumentIdentifier { DocumentUri = new(new Uri(documentPath)) },
+            Range = LspFactory.DefaultRange,
+            Context = new VSInternalCodeActionContext()
+        };
+
+        var context = CreateRazorCodeActionContext(request, cursorPosition, documentPath, contents, new SourceSpan(8, 4));
+
+        var provider = new CSharpCodeActionProvider(TestLanguageServerFeatureOptions.Instance);
+
+        ImmutableArray<RazorVSInternalCodeAction> codeActions =
+        [
+            new RazorVSInternalCodeAction()
+            {
+                Title = "Add accessibility modifiers",
+                Name = "AddAccessibilityModifiers"
+            }
+        ];
+
+        // Act
+        var providedCodeActions = await provider.ProvideAsync(context, codeActions, DisposalToken);
+
+        // Assert
+        Assert.NotEmpty(providedCodeActions);
+        Assert.Equal("AddAccessibilityModifiers", providedCodeActions[0].Name);
+    }
+
     private static RazorCodeActionContext CreateRazorCodeActionContext(
         VSCodeActionParams request,
         int absoluteIndex,