Added method to scan identifiers

Author: marcarro

src/Razor/src/Microsoft.AspNetCore.Razor.LanguageServer/CodeActions/Models/ExtractToNewComponentCodeActionParams.cs

@@ -23,4 +23,10 @@ internal sealed class ExtractToNewComponentCodeActionParams
 
     [JsonPropertyName("dependencies")]
     public required List<string> Dependencies { get; set; }
+
+    [JsonPropertyName("usedIdentifiers")]
+    public required HashSet<string> UsedIdentifiers { get; set; }
+
+    [JsonPropertyName("usedMembers")]
+    public required HashSet<string> UsedMembers { get; set; }
 }

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

@@ -1,5 +1,5 @@
 // Copyright (c) .NET Foundation. All rights reserved.
-// Licensed under the MIT license. See License.txt in the project root for license information.
+// Licensed under the MIT license. See License.txt in the project divNode for license information.
 
 using System;
 using System.Collections.Generic;
@@ -17,6 +17,7 @@
 using Microsoft.AspNetCore.Razor.Language.Syntax;
 using Microsoft.AspNetCore.Razor.LanguageServer.CodeActions.Models;
 using Microsoft.AspNetCore.Razor.Threading;
+using Microsoft.CodeAnalysis.CSharp.Syntax;
 using Microsoft.CodeAnalysis.Razor.Logging;
 using Microsoft.CodeAnalysis.Razor.Workspaces;
 using Microsoft.CodeAnalysis.Text;
@@ -58,25 +59,30 @@ public Task<ImmutableArray<RazorVSInternalCodeAction>> ProvideAsync(RazorCodeAct
             return SpecializedTasks.EmptyImmutableArray<RazorVSInternalCodeAction>();
         }
 
+        if (endElementNode is null)
+        {
+            endElementNode = startElementNode;
+        }
+
         if (!TryGetNamespace(context.CodeDocument, out var @namespace))
         {
             return SpecializedTasks.EmptyImmutableArray<RazorVSInternalCodeAction>();
         }
 
-        var actionParams = CreateInitialActionParams(context, startElementNode, @namespace);
-
-        var dependencyScanRoot = FindNearestCommonAncestor(startElementNode, endElementNode);
-
-        AddComponentDependenciesInRange(dependencyScanRoot,
-                                        actionParams.ExtractStart,
-                                        actionParams.ExtractEnd,
-                                        actionParams);
+        var actionParams = CreateInitialActionParams(context, startElementNode, @namespace);        
 
         if (IsMultiPointSelection(context.Request.Range))
         {
             ProcessMultiPointSelection(startElementNode, endElementNode, actionParams);
         }
 
+        var utilityScanRoot = FindNearestCommonAncestor(startElementNode, endElementNode) ?? startElementNode;
+        AddComponentDependenciesInRange(utilityScanRoot,
+                                        actionParams.ExtractStart,
+                                        actionParams.ExtractEnd,
+                                        actionParams);
+        GetUsedIdentifiers(utilityScanRoot, syntaxTree.Root, actionParams);
+
         var resolutionParams = new RazorCodeActionResolutionParams()
         {
             Action = LanguageServerConstants.CodeActions.ExtractToNewComponentAction,
@@ -105,8 +111,6 @@ private static (MarkupElementSyntax? Start, MarkupElementSyntax? End) GetStartAn
 
         var endElementNode = GetEndElementNode(context, syntaxTree, logger);
 
-        endElementNode ??= startElementNode;
-
         return (startElementNode, endElementNode);
     }
 
@@ -144,7 +148,7 @@ private static bool IsInsideProperHtmlContent(RazorCodeActionContext context, Ma
             return null;
         }
 
-        // Correct selection to include the current node if the selection ends immediately after a closing tag.
+        // Correct selection to include the current node if the selection ends at the "edge" (i.e. immediately after the ">") of a tag.
         if (string.IsNullOrWhiteSpace(endOwner.ToFullString()) && endOwner.TryGetPreviousSibling(out var previousSibling))
         {
             endOwner = previousSibling;
@@ -161,7 +165,9 @@ private static ExtractToNewComponentCodeActionParams CreateInitialActionParams(R
             ExtractStart = startElementNode.Span.Start,
             ExtractEnd = startElementNode.Span.End,
             Namespace = @namespace,
-            Dependencies = []
+            Dependencies = [],
+            UsedIdentifiers = [],
+            UsedMembers = [],
         };
     }
 
@@ -236,7 +242,7 @@ private static (SyntaxNode? Start, SyntaxNode? End) FindContainingSiblingPair(Sy
     {
         // Find the lowest common ancestor of both nodes
         var nearestCommonAncestor = FindNearestCommonAncestor(startNode, endNode);
-        if (nearestCommonAncestor == null)
+        if (nearestCommonAncestor is null)
         {
             return (null, null);
         }
@@ -248,11 +254,11 @@ private static (SyntaxNode? Start, SyntaxNode? End) FindContainingSiblingPair(Sy
         var startSpan = startNode.Span;
         var endSpan = endNode.Span;
 
-        foreach (var child in nearestCommonAncestor.ChildNodes().Where(node => node.Kind == SyntaxKind.MarkupElement))
+        foreach (var child in nearestCommonAncestor.ChildNodes().Where(node => node is MarkupElementSyntax))
         {
             var childSpan = child.Span;
 
-            if (startContainingNode == null && childSpan.Contains(startSpan))
+            if (startContainingNode is null && childSpan.Contains(startSpan))
             {
                 startContainingNode = child;
                 if (endContainingNode is not null)
@@ -274,7 +280,7 @@ private static (SyntaxNode? Start, SyntaxNode? End) FindContainingSiblingPair(Sy
     {
         var current = node1;
 
-        while (current.Kind == SyntaxKind.MarkupElement && current is not null)
+        while (current is MarkupElementSyntax && current is not null)
         {
             if (current.Span.Contains(node2.Span))
             {
@@ -297,7 +303,7 @@ private static void AddComponentDependenciesInRange(SyntaxNode root, int extract
             if (IsMarkupTagHelperElement(node, extractSpan))
             {
                 var tagHelperInfo = GetTagHelperInfo(node);
-                if (tagHelperInfo != null)
+                if (tagHelperInfo is not null)
                 {
                     AddDependenciesFromTagHelperInfo(tagHelperInfo, components, actionParams);
                 }
@@ -325,7 +331,7 @@ private static void AddDependenciesFromTagHelperInfo(TagHelperInfo tagHelperInfo
     {
         foreach (var descriptor in tagHelperInfo.BindingResult.Descriptors)
         {
-            if (descriptor != null)
+            if (descriptor is not null)
             {
                 foreach (var metadata in descriptor.Metadata)
                 {
@@ -340,4 +346,27 @@ metadata.Value is not null &&
             }
         }
     }
+
+    private static void GetUsedIdentifiers(SyntaxNode divNode, SyntaxNode documentRoot, ExtractToNewComponentCodeActionParams actionParams)
+    {
+        HashSet<string> identifiersInScope = [];
+        HashSet<string> identifiersInBlock = [];
+
+
+        foreach (var node in divNode.DescendantNodes().Where(static node => node.Kind is SyntaxKind.Identifier))
+        {
+            identifiersInScope.Add(node.GetContent());
+        }
+
+        foreach (var codeBlock in documentRoot.DescendantNodes().Where(static node => node.Kind is SyntaxKind.RazorDirective))
+        {
+            foreach (var node in codeBlock.DescendantNodes().Where(static node => node.Kind is SyntaxKind.Identifier))
+            {
+                identifiersInBlock.Add(node.GetContent());
+            }
+        }
+
+        identifiersInBlock.IntersectWith(identifiersInScope);
+        actionParams.UsedIdentifiers = identifiersInBlock;
+    }
 }

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

@@ -118,6 +118,67 @@ public async Task Handle_SinglePointSelection_ReturnsNotEmpty()
         Assert.NotEmpty(commandOrCodeActionContainer);
     }
 
+    [Fact]
+    public async Task Handle_CodeInsideDiv_ScansCorrect()
+    {
+        // Arrange
+        var documentPath = "c:/Test.cs";
+        var contents = """
+            @page "/"
+
+            <PageTitle>Home</PageTitle>
+
+            <$$div id="codeInside">
+                @for(int idx = 0; idx < 10; idx++) {
+                    string s = someFunc(idx * myField);
+                }
+            </div>
+
+            <div id="parent">
+                <div>
+                    <h1>Div a title</h1>
+                    <p>Div a par</p>
+                </div>
+                <div>
+                    <h1>Div b title</h1>
+                    <p>Div b par</p>
+                </div>
+            </div>
+
+            @code {
+                public int myField = 7;
+
+                public string someFunc(int num) {
+                    return "Hello for number" + num;
+                }
+            }
+            """;
+        TestFileMarkupParser.GetPosition(contents, out contents, out var cursorPosition);
+
+        var request = new VSCodeActionParams()
+        {
+            TextDocument = new VSTextDocumentIdentifier { Uri = new Uri(documentPath) },
+            Range = new Range(),
+            Context = new VSInternalCodeActionContext()
+        };
+
+        var location = new SourceLocation(cursorPosition, -1, -1);
+        var context = CreateRazorCodeActionContext(request, location, documentPath, contents);
+
+        var provider = new ExtractToNewComponentCodeActionProvider(LoggerFactory);
+
+        // Act
+        var commandOrCodeActionContainer = await provider.ProvideAsync(context, default);
+
+        // Assert
+        Assert.NotEmpty(commandOrCodeActionContainer);
+        var codeAction = Assert.Single(commandOrCodeActionContainer);
+        var razorCodeActionResolutionParams = ((JsonElement)codeAction.Data!).Deserialize<RazorCodeActionResolutionParams>();
+        Assert.NotNull(razorCodeActionResolutionParams);
+        var actionParams = ((JsonElement)razorCodeActionResolutionParams.Data).Deserialize<ExtractToNewComponentCodeActionParams>();
+        Assert.NotNull(actionParams);
+    }
+
     [Fact]
     public async Task Handle_MultiPointSelection_ReturnsNotEmpty()
     {
@@ -176,8 +237,8 @@ public async Task Handle_MultiPointSelectionWithEndAtEdge_ReturnsCurrentElement(
         // Arrange
         var documentPath = "c:/Test.cs";
         var contents = """
-            @namespace MarketApp.Pages.Product.Home
             @page "/"
+            @namespace MarketApp.Pages.Product.Home
 
             namespace MarketApp.Pages.Product.Home