Address code review feedback: allow data-enhance-nav on any element and refactor duplicate check

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

Author: Copilot

src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/Completion/BlazorDataAttributeCompletionItemProvider.cs

@@ -86,34 +86,23 @@ public ImmutableArray<RazorCompletionItem> GetCompletionItems(RazorCompletionCon
                 continue;
             }
 
-            // Only show data-enhance-nav for anchor elements
-            if (attributeName == "data-enhance-nav" &&
-                !string.Equals(containingTagName, "a", System.StringComparison.OrdinalIgnoreCase))
-            {
-                continue;
-            }
+            // data-enhance-nav can go on any element, no filtering needed
 
             // Check if the attribute already exists on the element
             var alreadyExists = false;
             foreach (var attribute in attributes)
             {
-                if (attribute.Kind == AspNetCore.Razor.Language.SyntaxKind.MarkupAttributeBlock)
+                var existingAttributeName = attribute.Kind switch
                 {
-                    var attrBlock = (MarkupAttributeBlockSyntax)attribute;
-                    if (string.Equals(attrBlock.Name.GetContent(), attributeName, System.StringComparison.Ordinal))
-                    {
-                        alreadyExists = true;
-                        break;
-                    }
-                }
-                else if (attribute.Kind == AspNetCore.Razor.Language.SyntaxKind.MarkupMinimizedAttributeBlock)
+                    AspNetCore.Razor.Language.SyntaxKind.MarkupAttributeBlock => ((MarkupAttributeBlockSyntax)attribute).Name.GetContent(),
+                    AspNetCore.Razor.Language.SyntaxKind.MarkupMinimizedAttributeBlock => ((MarkupMinimizedAttributeBlockSyntax)attribute).Name.GetContent(),
+                    _ => null
+                };
+
+                if (existingAttributeName != null && string.Equals(existingAttributeName, attributeName, System.StringComparison.Ordinal))
                 {
-                    var minAttrBlock = (MarkupMinimizedAttributeBlockSyntax)attribute;
-                    if (string.Equals(minAttrBlock.Name.GetContent(), attributeName, System.StringComparison.Ordinal))
-                    {
-                        alreadyExists = true;
-                        break;
-                    }
+                    alreadyExists = true;
+                    break;
                 }
             }
 

src/Razor/test/Microsoft.CodeAnalysis.Razor.Workspaces.Test/Completion/BlazorDataAttributeCompletionItemProviderTest.cs

@@ -101,9 +101,9 @@ public void GetCompletionItems_OnNonFormElement_DoesNotReturnDataEnhance()
     }
 
     [Fact]
-    public void GetCompletionItems_OnNonAnchorElement_DoesNotReturnDataEnhanceNav()
+    public void GetCompletionItems_OnDivElement_ReturnsDataEnhanceNav()
     {
-        // Arrange
+        // Arrange - data-enhance-nav can go on any element, not just anchors
         TestCode testCode = "<div d$$></div>";
         var context = CreateRazorCompletionContext(testCode);
 
@@ -112,7 +112,7 @@ public void GetCompletionItems_OnNonAnchorElement_DoesNotReturnDataEnhanceNav()
 
         // Assert
         var dataEnhanceNav = completions.FirstOrDefault(c => c.DisplayText == "data-enhance-nav");
-        Assert.Null(dataEnhanceNav);
+        Assert.NotNull(dataEnhanceNav);
     }
 
     [Fact]

src/Razor/test/Microsoft.VisualStudio.LanguageServices.Razor.Test/Cohost/Shared/CohostDocumentCompletionEndpointTest.cs

@@ -746,6 +746,71 @@ The end.
         Assert.All(list.Items, item => Assert.DoesNotContain("=", item.CommitCharacters ?? []));
     }
 
+    [Fact]
+    public async Task BlazorDataEnhanceAttributeCompletion_OnFormElement()
+    {
+        await VerifyCompletionListAsync(
+            input: """
+                This is a Razor document.
+
+                <form d$$></form>
+
+                The end.
+                """,
+            completionContext: new VSInternalCompletionContext()
+            {
+                InvokeKind = VSInternalCompletionInvokeKind.Typing,
+                TriggerCharacter = "d",
+                TriggerKind = CompletionTriggerKind.TriggerCharacter
+            },
+            expectedItemLabels: ["data-enhance", "data-enhance-nav", "data-permanent", "dir"],
+            htmlItemLabels: ["dir"]);
+    }
+
+    [Fact]
+    public async Task BlazorDataEnhanceNavAttributeCompletion_OnAnyElement()
+    {
+        await VerifyCompletionListAsync(
+            input: """
+                This is a Razor document.
+
+                <div d$$></div>
+
+                The end.
+                """,
+            completionContext: new VSInternalCompletionContext()
+            {
+                InvokeKind = VSInternalCompletionInvokeKind.Typing,
+                TriggerCharacter = "d",
+                TriggerKind = CompletionTriggerKind.TriggerCharacter
+            },
+            expectedItemLabels: ["data-enhance-nav", "data-permanent", "dir"],
+            unexpectedItemLabels: ["data-enhance"],
+            htmlItemLabels: ["dir"]);
+    }
+
+    [Fact]
+    public async Task BlazorDataPermanentAttributeCompletion_OnAnchorElement()
+    {
+        await VerifyCompletionListAsync(
+            input: """
+                This is a Razor document.
+
+                <a d$$></a>
+
+                The end.
+                """,
+            completionContext: new VSInternalCompletionContext()
+            {
+                InvokeKind = VSInternalCompletionInvokeKind.Typing,
+                TriggerCharacter = "d",
+                TriggerKind = CompletionTriggerKind.TriggerCharacter
+            },
+            expectedItemLabels: ["data-enhance-nav", "data-permanent", "dir"],
+            unexpectedItemLabels: ["data-enhance"],
+            htmlItemLabels: ["dir"]);
+    }
+
     private async Task<RazorVSInternalCompletionList> VerifyCompletionListAsync(
         TestCode input,
         VSInternalCompletionContext completionContext,