Completed and corrected selected range extraction functionality

FROM MERGE

Author: marcarro

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

@@ -229,6 +229,127 @@ @namespace MarketApp.Pages.Product.Home
         Assert.Equal(selectionSpan.End, actionParams.ExtractEnd);
     }
 
+    [Fact]
+    public async Task Handle_InProperMarkup_ReturnsNull()
+    {
+        // Arrange
+        var documentPath = "c:/Test.razor";
+        var contents = """
+            page "/"
+            
+            <PageTitle>Home</PageTitle>
+            
+            <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
+            
+            <h1>Hello, world!</h1>
+            
+            Welcome to your new app.
+            """;
+        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.Null(commandOrCodeActionContainer);
+    }
+
+    [Theory]
+    [InlineData("""
+    <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>
+    """)]
+    [InlineData("""
+    <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>
+    """)]
+    [InlineData("""
+    <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>
+    """)]
+    public async Task Handle_ValidElementSelection_ReturnsNotNull(string markupElementSelection)
+    {
+        // Arrange
+        var documentPath = "c:/Test.razor";
+        var contents = $$"""
+            page "/"
+            
+            <PageTitle>Home</PageTitle>
+            
+            {{markupElementSelection}}
+      
+            <h1>Hello, world!</h1>
+            
+            Welcome to your new app.
+            """;
+
+        TestFileMarkupParser.GetPositionAndSpans(
+            contents, out contents, out int cursorPosition, out ImmutableArray<TextSpan> spans);
+
+        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, supportsFileCreation: true);
+
+        var provider = new ExtractToNewComponentCodeActionProvider(LoggerFactory);
+
+        // Act
+        var commandOrCodeActionContainer = await provider.ProvideAsync(context, default);
+
+        // Assert
+        Assert.NotNull(commandOrCodeActionContainer);
+    }
+
     private static RazorCodeActionContext CreateRazorCodeActionContext(VSCodeActionParams request, SourceLocation location, string filePath, string text, bool supportsFileCreation = true)
         => CreateRazorCodeActionContext(request, location, filePath, text, relativePath: filePath, supportsFileCreation: supportsFileCreation);