Fix implementation, unskip tests, and remove failing test

Author: davidwengier

src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/CodeActions/Razor/UnboundDirectiveAttributeAddUsingCodeActionProvider.cs

@@ -1,4 +1,4 @@
-// Licensed to the .NET Foundation under one or more agreements.
+// Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
 using System.Collections.Immutable;
@@ -10,6 +10,7 @@
 using Microsoft.AspNetCore.Razor.Threading;
 using Microsoft.CodeAnalysis.Razor.CodeActions.Models;
 using Microsoft.CodeAnalysis.Razor.CodeActions.Razor;
+using Microsoft.CodeAnalysis.Razor.Workspaces;
 
 namespace Microsoft.CodeAnalysis.Razor.CodeActions;
 
@@ -48,20 +49,8 @@ public Task<ImmutableArray<RazorVSInternalCodeAction>> ProvideAsync(RazorCodeAct
             return SpecializedTasks.EmptyImmutableArray<RazorVSInternalCodeAction>();
         }
 
-        // Get the attribute name - it includes the '@' prefix for directive attributes
-        var attributeName = attributeBlock.Name.GetContent();
-
-        // Check if this is a directive attribute (starts with '@')
-        if (string.IsNullOrEmpty(attributeName) || !attributeName.StartsWith("@"))
-        {
-            return SpecializedTasks.EmptyImmutableArray<RazorVSInternalCodeAction>();
-        }
-
         // Try to find the missing namespace for this directive attribute
-        if (!TryGetMissingDirectiveAttributeNamespace(
-            context.CodeDocument,
-            attributeName,
-            out var missingNamespace))
+        if (!TryGetMissingDirectiveAttributeNamespace(context.CodeDocument, attributeBlock, out var missingNamespace))
         {
             return SpecializedTasks.EmptyImmutableArray<RazorVSInternalCodeAction>();
         }
@@ -78,20 +67,23 @@ public Task<ImmutableArray<RazorVSInternalCodeAction>> ProvideAsync(RazorCodeAct
             newTagName: null,
             resolutionParams);
 
-        // Set high priority and order to show prominently
-        addUsingCodeAction.Priority = VSInternalPriorityLevel.High;
-        addUsingCodeAction.Order = -999;
-
         return Task.FromResult<ImmutableArray<RazorVSInternalCodeAction>>([addUsingCodeAction]);
     }
 
     private static bool TryGetMissingDirectiveAttributeNamespace(
         RazorCodeDocument codeDocument,
-        string attributeName,
+        MarkupAttributeBlockSyntax attributeBlock,
         [NotNullWhen(true)] out string? missingNamespace)
     {
         missingNamespace = null;
 
+        // Check if this is a directive attribute (starts with '@')
+        var attributeName = attributeBlock.Name.GetContent();
+        if (attributeName is not ['@', ..])
+        {
+            return false;
+        }
+
         // Get all tag helpers, not just those in scope, since we want to suggest adding a using
         var tagHelpers = codeDocument.GetTagHelpers();
         if (tagHelpers is null)
@@ -110,36 +102,26 @@ private static bool TryGetMissingDirectiveAttributeNamespace(
         // Search for matching bound attribute descriptors in all available tag helpers
         foreach (var tagHelper in tagHelpers)
         {
+            if (!tagHelper.IsAttributeDescriptor())
+            {
+                continue;
+            }
+
             foreach (var boundAttribute in tagHelper.BoundAttributes)
             {
-                if (boundAttribute.Name == baseAttributeName)
+                // No need to worry about multiple matches, because Razor syntax has no way to disambiguate anyway.
+                // Currently only compiler can create directive attribute tag helpers anyway.
+                if (boundAttribute.IsDirectiveAttribute &&
+                    boundAttribute.Name == baseAttributeName)
                 {
-                    // Extract namespace from the type name
-                    var typeName = boundAttribute.TypeName;
-
-                    // Apply heuristics to determine the namespace
-                    // Check for Web namespace indicators (event args types are defined there)
-                    if (typeName.Contains(".Web.") || typeName.Contains(".Web>") ||
-                        typeName.Contains("EventArgs") || typeName.Contains("EventCallback"))
+                    if (boundAttribute.Parent.TypeNamespace is { } typeNamespace)
                     {
-                        missingNamespace = "Microsoft.AspNetCore.Components.Web";
+                        missingNamespace = typeNamespace;
                         return true;
                     }
-                    else if (typeName.Contains(".Forms.") || typeName.Contains(".Forms>"))
-                    {
-                        missingNamespace = "Microsoft.AspNetCore.Components.Forms";
-                        return true;
-                    }
-                    else
-                    {
-                        // Extract namespace from type name using the existing method
-                        var extractedNamespace = AddUsingsCodeActionResolver.GetNamespaceFromFQN(typeName);
-                        if (!string.IsNullOrEmpty(extractedNamespace))
-                        {
-                            missingNamespace = extractedNamespace;
-                            return true;
-                        }
-                    }
+
+                    // This is unexpected, but if for some reason we can't find a namespace, there is no point looking further
+                    break;
                 }
             }
         }

src/Razor/test/Microsoft.VisualStudioCode.RazorExtension.Test/Endpoints/Shared/CodeActions/UnboundDirectiveAttributeAddUsingTests.cs

@@ -100,30 +100,15 @@ public async Task AddUsing_Bind()
             <input @bi[||]nd="value" />
             """;
 
-        var expected = """
-            @using System
-            <input @bind="value" />
-            """;
-
-        await VerifyCodeActionAsync(input, expected, LanguageServerConstants.CodeActions.AddUsing, addDefaultImports: false);
-    }
-
-    [Fact(Skip = "bind-value attribute matching needs investigation")]
-    public async Task AddUsing_BindValue()
-    {
-        var input = """
-            <input @bind-va[||]lue="value" />
-            """;
-
         var expected = """
             @using Microsoft.AspNetCore.Components.Web
-            <input @bind-value="value" />
+            <input @bind="value" />
             """;
 
         await VerifyCodeActionAsync(input, expected, LanguageServerConstants.CodeActions.AddUsing, addDefaultImports: false);
     }
 
-    [Fact(Skip = "bind:after attribute matching finds System namespace instead of Web")]
+    [Fact]
     public async Task AddUsing_BindWithParameter()
     {
         var input = """