Add breadcrumb tests

Author: Mpdreamz

src/Elastic.Markdown/IO/MarkdownFile.cs

@@ -54,6 +54,19 @@ public string? NavigationTitle
 
 	private bool _instructionsParsed;
 
+	public MarkdownFile[] YieldParents()
+	{
+		var parents = new List<MarkdownFile>();
+		var parent = Parent;
+		do
+		{
+			if (parent is { Index: not null } && parent.Index != this)
+				parents.Add(parent.Index);
+			parent = parent?.Parent;
+		} while (parent != null);
+		return parents.ToArray();
+	}
+
 	public async Task<MarkdownDocument> MinimalParse(Cancel ctx)
 	{
 		var document = await MarkdownParser.MinimalParseAsync(SourceFile, ctx);

src/Elastic.Markdown/Slices/_ViewModels.cs

@@ -35,16 +35,7 @@ public MarkdownFile[] Parents
 			if (_parents is not null)
 				return _parents;
 
-			var parents = new List<MarkdownFile>();
-			var current = CurrentDocument.Parent;
-			do
-			{
-				if (current is { Index: not null } && current.Index != CurrentDocument)
-					parents.Add(current.Index);
-				current = current?.Parent;
-			} while (current != null);
-
-			_parents = [.. parents];
+			_parents = [.. CurrentDocument.YieldParents()];
 			return _parents;
 		}
 	}

tests/Elastic.Markdown.Tests/SiteMap/BreadCrumbTests.cs

@@ -0,0 +1,25 @@
+// Licensed to Elasticsearch B.V under one or more agreements.
+// Elasticsearch B.V licenses this file to you under the Apache 2.0 License.
+// See the LICENSE file in the project root for more information
+
+using Elastic.Markdown.IO;
+using FluentAssertions;
+using Xunit.Abstractions;
+
+namespace Elastic.Markdown.Tests.SiteMap;
+
+public class BreadCrumbTests(ITestOutputHelper output) : NavigationTestsBase(output)
+{
+	[Fact]
+	public void ParsesATableOfContents()
+	{
+		var doc = Generator.DocumentationSet.Files.FirstOrDefault(f => f.RelativePath == "testing/nested/index.md") as MarkdownFile;
+
+		doc.Should().NotBeNull();
+
+		doc!.Parent.Should().NotBeNull();
+
+		doc.YieldParents().Should().HaveCount(2);
+
+	}
+}