added tests linking to inline anchors

Author: Mpdreamz

src/Elastic.Markdown/IO/MarkdownFile.cs

@@ -170,7 +170,7 @@ private void ReadDocumentInstructions(MarkdownDocument document)
 			.Select(s => s.Slugify())
 			.Concat(document.Descendants<InlineAnchor>().Select(a=>a.Anchor))
 			.ToArray();
-		
+
 		foreach (var label in labels)
 		{
 			if (!string.IsNullOrEmpty(label))

src/Elastic.Markdown/Myst/MarkdownParser.cs

@@ -31,6 +31,7 @@ public class MarkdownParser(
 	public static MarkdownPipeline MinimalPipeline { get; } =
 		new MarkdownPipelineBuilder()
 			.UseYamlFrontMatter()
+			.UseInlineAnchors()
 			.UseHeadingsWithSlugs()
 			.UseDirectives()
 			.Build();

tests/Elastic.Markdown.Tests/Inline/InlineAnchorTests.cs

@@ -2,9 +2,12 @@
 // 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 System.IO.Abstractions.TestingHelpers;
 using Elastic.Markdown.Myst.InlineParsers;
 using FluentAssertions;
+using JetBrains.Annotations;
 using Markdig.Syntax;
+using Markdig.Syntax.Inlines;
 using Xunit.Abstractions;
 
 namespace Elastic.Markdown.Tests.Inline;
@@ -135,3 +138,74 @@ public void GeneratesAttributesInHtml() =>
 			""".TrimEnd()
 		);
 }
+
+
+public abstract class InlineAnchorLinkTestBase(ITestOutputHelper output, [LanguageInjection("markdown")] string content)
+	: InlineTest<LinkInline>(output,
+$"""
+## Hello world
+
+A paragraph
+
+{content}
+
+$$$same-page-anchor$$$
+
+""")
+{
+	protected override void AddToFileSystem(MockFileSystem fileSystem)
+	{
+		// language=markdown
+		var inclusion =
+"""
+# Special Requirements
+
+## Sub Requirements
+
+To follow this tutorial you will need to install the following components:
+
+## New Requirements [#new-reqs]
+
+These are new requirements
+
+With a custom anchor that exists temporarily. $$$custom-anchor$$$
+""";
+		fileSystem.AddFile(@"docs/testing/req.md", inclusion);
+		fileSystem.AddFile(@"docs/_static/img/observability.png", new MockFileData(""));
+	}
+
+}
+
+public class InlineAnchorCanBeLinkedToo(ITestOutputHelper output) : InlineAnchorLinkTestBase(output,
+"""
+[Hello](#same-page-anchor)
+"""
+)
+{
+	[Fact]
+	public void GeneratesHtml() =>
+		// language=html
+		Html.Should().Contain(
+			"""<p><a href="#same-page-anchor">Hello</a></p>"""
+		);
+
+	[Fact]
+	public void HasNoErrors() => Collector.Diagnostics.Should().HaveCount(0);
+}
+
+public class ExternalPageInlineAnchorCanBeLinkedToo(ITestOutputHelper output) : InlineAnchorLinkTestBase(output,
+"""
+[Sub Requirements](testing/req.md#custom-anchor)
+"""
+)
+{
+	[Fact]
+	public void GeneratesHtml() =>
+		// language=html
+		Html.Should().Contain(
+			"""<p><a href="testing/req.html#custom-anchor">Sub Requirements</a></p>"""
+		);
+
+	[Fact]
+	public void HasNoErrors() => Collector.Diagnostics.Should().HaveCount(0);
+}