Support component rename from an end tag (#10762)

Fixes https://github.com/dotnet/razor/issues/10717

src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/Rename/RenameService.cs

@@ -5,6 +5,7 @@ using System;
 using System.Collections.Generic;
 using System.Collections.Immutable;
 using System.Diagnostics;
+using System.Diagnostics.CodeAnalysis;
 using System.IO;
 using System.Linq;
 using System.Threading;
@@ -250,23 +251,7 @@ internal class RenameService(
             return default;
         }
 
-        var node = owner.FirstAncestorOrSelf<RazorSyntaxNode>(n => n.Kind == RazorSyntaxKind.MarkupTagHelperStartTag);
-        if (node is not MarkupTagHelperStartTagSyntax tagHelperStartTag)
-        {
-            return default;
-        }
-
-        // Ensure the rename action was invoked on the component name
-        // instead of a component parameter. This serves as an issue
-        // mitigation till `textDocument/prepareRename` is supported
-        // and we can ensure renames aren't triggered in unsupported
-        // contexts. (https://github.com/dotnet/aspnetcore/issues/26407)
-        if (!tagHelperStartTag.Name.FullSpan.IntersectsWith(absoluteIndex))
-        {
-            return default;
-        }
-
-        if (tagHelperStartTag.Parent is not MarkupTagHelperElementSyntax { TagHelperInfo.BindingResult: var binding })
+        if (!TryGetTagHelperBinding(owner, absoluteIndex, out var binding))
         {
             return default;
         }
@@ -288,6 +273,43 @@ internal class RenameService(
         return [primaryTagHelper, associatedTagHelper];
     }
 
+    private static bool TryGetTagHelperBinding(RazorSyntaxNode owner, int absoluteIndex, [NotNullWhen(true)] out TagHelperBinding? binding)
+    {
+        // End tags are easy, because there is only one possible binding result
+        if (owner is MarkupTagHelperEndTagSyntax { Parent: MarkupTagHelperElementSyntax { TagHelperInfo.BindingResult: var endTagBindingResult } })
+        {
+            binding = endTagBindingResult;
+            return true;
+        }
+
+        // A rename of a start tag could have an "owner" of one of its attributes, so we do a bit more checking
+        // to support this case
+        var node = owner.FirstAncestorOrSelf<RazorSyntaxNode>(n => n.Kind == RazorSyntaxKind.MarkupTagHelperStartTag);
+        if (node is not MarkupTagHelperStartTagSyntax tagHelperStartTag)
+        {
+            binding = null;
+            return false;
+        }
+
+        // Ensure the rename action was invoked on the component name instead of a component parameter. This serves as an issue
+        // mitigation till `textDocument/prepareRename` is supported and we can ensure renames aren't triggered in unsupported
+        // contexts. (https://github.com/dotnet/razor/issues/4285)
+        if (!tagHelperStartTag.Name.FullSpan.IntersectsWith(absoluteIndex))
+        {
+            binding = null;
+            return false;
+        }
+
+        if (tagHelperStartTag is { Parent: MarkupTagHelperElementSyntax { TagHelperInfo.BindingResult: var startTagBindingResult } })
+        {
+            binding = startTagBindingResult;
+            return true;
+        }
+
+        binding = null;
+        return false;
+    }
+
     private static TagHelperDescriptor? FindAssociatedTagHelper(TagHelperDescriptor tagHelper, ImmutableArray<TagHelperDescriptor> tagHelpers)
     {
         var typeName = tagHelper.GetTypeName();

src/Razor/test/Microsoft.AspNetCore.Razor.LanguageServer.Test/Refactoring/RenameEndpointTest.cs

@@ -265,6 +265,29 @@ public class RenameEndpointTest(ITestOutputHelper testOutput) : LanguageServerTe
         Assert.NotNull(result);
     }
 
+    [Fact]
+    public async Task Handle_Rename_OnComponentEndTag_ReturnsResult()
+    {
+        // Arrange
+        var (endpoint, documentContextFactory) = await CreateEndpointAndDocumentContextFactoryAsync();
+        var uri = PathUtilities.GetUri(s_componentWithParamFilePath);
+        var request = new RenameParams
+        {
+            TextDocument = new() { Uri = uri },
+            Position = VsLspFactory.CreatePosition(1, 36),
+            NewName = "Test2"
+        };
+
+        Assert.True(documentContextFactory.TryCreateForOpenDocument(uri, out var documentContext));
+        var requestContext = CreateRazorRequestContext(documentContext);
+
+        // Act
+        var result = await endpoint.HandleRequestAsync(request, requestContext, DisposalToken);
+
+        // Assert
+        Assert.NotNull(result);
+    }
+
     [Fact]
     public async Task Handle_Rename_OnComponentNameTrailingEdge_ReturnsResult()
     {

src/Razor/test/Microsoft.VisualStudio.LanguageServices.Razor.Test/Cohost/CohostRenameEndpointTest.cs

@@ -112,62 +112,62 @@ public class CohostRenameEndpointTest(ITestOutputHelper testOutputHelper) : Coho
                 """,
             renames: [("Component.razor", "DifferentName.razor")]);
 
-    [Theory(Skip = "https://github.com/dotnet/razor/issues/10717")]
+    [Theory]
     [InlineData("$$Component")]
     [InlineData("Com$$ponent")]
     [InlineData("Component$$")]
     public Task Component_EndTag(string endTag)
-    => VerifyRenamesAsync(
-        input: $"""
-            This is a Razor document.
+        => VerifyRenamesAsync(
+            input: $"""
+                This is a Razor document.
 
-            <Component />
-
-            <div>
                 <Component />
-                <Component>
-                </Component>
+
                 <div>
                     <Component />
                     <Component>
-                    </{endTag}>
+                    </Component>
+                    <div>
+                        <Component />
+                        <Component>
+                        </{endTag}>
+                    </div>
                 </div>
-            </div>
 
-            The end.
-            """,
-        additionalFiles: [
-            // The source generator isn't hooked up to our test project, so we have to manually "compile" the razor file
-            (File("Component.cs"), """
-                namespace SomeProject;
+                The end.
+                """,
+            additionalFiles: [
+                // The source generator isn't hooked up to our test project, so we have to manually "compile" the razor file
+                (File("Component.cs"), """
+                    namespace SomeProject;
 
-                public class Component : Microsoft.AspNetCore.Components.ComponentBase
-                {
-                }
-                """),
-            // The above will make the component exist, but the .razor file needs to exist too for Uri presentation
-            (File("Component.razor"), "")
-        ],
-        newName: "DifferentName",
-        expected: """
-            This is a Razor document.
+                    public class Component : Microsoft.AspNetCore.Components.ComponentBase
+                    {
+                    }
+                    """),
+                // The above will make the component exist, but the .razor file needs to exist too for Uri presentation
+                (File("Component.razor"), "")
+            ],
+            newName: "DifferentName",
+            expected: """
+                This is a Razor document.
 
-            <DifferentName />
-                
-            <div>
                 <DifferentName />
-                <DifferentName>
-                </DifferentName>
+
                 <div>
                     <DifferentName />
                     <DifferentName>
                     </DifferentName>
+                    <div>
+                        <DifferentName />
+                        <DifferentName>
+                        </DifferentName>
+                    </div>
                 </div>
-            </div>
 
-            The end.
-            """,
-        renames: [("Component.razor", "DifferentName.razor")]);
+                The end.
+                """,
+            renames: [("Component.razor", "DifferentName.razor")]);
 
     [Fact]
     public Task Mvc()