Add cross-links to links.json

docs/source/docset.yml

@@ -77,3 +77,4 @@ toc:
       - file: index.md
       - file: req.md
       - folder: nested
+      - file: cross-links.md

docs/source/testing/cross-links.md

@@ -0,0 +1,9 @@
+---
+title: Cross Links
+---
+
+[Elasticsearch](elasticsearch://index.md)
+
+[Kibana][1]
+
+[1]: kibana://index.md

src/Elastic.Markdown/Diagnostics/DiagnosticsChannel.cs

@@ -2,6 +2,7 @@
 // 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.Collections.Concurrent;
 using System.Threading.Channels;
 using Microsoft.Extensions.Hosting;
 using Microsoft.Extensions.Logging;
@@ -86,6 +87,8 @@ public class DiagnosticsCollector(ILoggerFactory loggerFactory, IReadOnlyCollect
 
 	public HashSet<string> OffendingFiles { get; } = new();
 
+	public ConcurrentBag<string> CrossLinks { get; } = new();
+
 	public Task StartAsync(Cancel ctx)
 	{
 		if (_started is not null)
@@ -140,6 +143,7 @@ public virtual async Task StopAsync(CancellationToken cancellationToken)
 		await Channel.Reader.Completion;
 	}
 
+	public void EmitCrossLink(string link) => CrossLinks.Add(link);
 
 	public void EmitError(string file, string message, Exception? e = null)
 	{

src/Elastic.Markdown/IO/LinkReference.cs

@@ -17,16 +17,21 @@ public record LinkReference
 	[JsonPropertyName("links")]
 	public required string[] Links { get; init; } = [];
 
+	[JsonPropertyName("cross_links")]
+	public required string[] CrossLinks { get; init; } = [];
+
 	public static LinkReference Create(DocumentationSet set)
 	{
+		var crossLinks = set.Context.Collector.CrossLinks.ToHashSet().ToArray();
 		var links = set.FlatMappedFiles.Values
 			.OfType<MarkdownFile>()
 			.Select(m => m.RelativePath).ToArray();
 		return new LinkReference
 		{
 			UrlPathPrefix = set.Context.UrlPathPrefix,
 			Origin = set.Context.Git,
-			Links = links
+			Links = links,
+			CrossLinks = crossLinks
 		};
 	}
 }

src/Elastic.Markdown/Myst/InlineParsers/DiagnosticLinkInlineParser.cs

@@ -2,15 +2,14 @@
 // 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.Collections.Immutable;
 using Elastic.Markdown.Diagnostics;
 using Elastic.Markdown.IO;
-using Elastic.Markdown.Myst.Directives;
 using Markdig;
 using Markdig.Helpers;
 using Markdig.Parsers;
 using Markdig.Parsers.Inlines;
 using Markdig.Renderers;
-using Markdig.Syntax;
 using Markdig.Syntax.Inlines;
 
 namespace Elastic.Markdown.Myst.InlineParsers;
@@ -34,6 +33,10 @@ public void Setup(MarkdownPipeline pipeline, IMarkdownRenderer renderer) { }
 
 public class DiagnosticLinkInlineParser : LinkInlineParser
 {
+	// See https://www.iana.org/assignments/uri-schemes/uri-schemes.xhtml for a list of URI schemes
+	// We can add more schemes as needed
+	private static readonly ImmutableHashSet<string> ExcludedSchemes = ["http", "https", "tel", "jdbc"];
+
 	public override bool Match(InlineProcessor processor, ref StringSlice slice)
 	{
 		var match = base.Match(processor, ref slice);
@@ -48,6 +51,7 @@ public override bool Match(InlineProcessor processor, ref StringSlice slice)
 		var column = link.Column;
 		var length = url?.Length ?? 1;
 
+
 		var context = processor.GetContext();
 		if (processor.GetContext().SkipValidation)
 			return match;
@@ -58,7 +62,12 @@ public override bool Match(InlineProcessor processor, ref StringSlice slice)
 			return match;
 		}
 
-		if (Uri.TryCreate(url, UriKind.Absolute, out var uri) && uri.Scheme.StartsWith("http"))
+		var uri = Uri.TryCreate(url, UriKind.Absolute, out var u) ? u : null;
+
+		if (IsCrossLink(uri))
+			processor.GetContext().Build.Collector.EmitCrossLink(url!);
+
+		if (uri != null && uri.Scheme.StartsWith("http"))
 		{
 			var baseDomain = uri.Host == "localhost" ? "localhost" : string.Join('.', uri.Host.Split('.')[^2..]);
 			if (!context.Configuration.ExternalLinkHosts.Contains(baseDomain))
@@ -82,15 +91,11 @@ public override bool Match(InlineProcessor processor, ref StringSlice slice)
 		var anchor = anchors.Length > 1 ? anchors[1].Trim() : null;
 		url = anchors[0];
 
-		if (!string.IsNullOrWhiteSpace(url))
+		if (!string.IsNullOrWhiteSpace(url) && uri != null)
 		{
 			var pathOnDisk = Path.Combine(includeFrom, url.TrimStart('/'));
-			if (!context.Build.ReadFileSystem.File.Exists(pathOnDisk))
+			if (uri.IsFile && !context.Build.ReadFileSystem.File.Exists(pathOnDisk))
 				processor.EmitError(line, column, length, $"`{url}` does not exist. resolved to `{pathOnDisk}");
-			else
-			{
-
-			}
 		}
 		else
 			link.Url = "";
@@ -128,8 +133,11 @@ public override bool Match(InlineProcessor processor, ref StringSlice slice)
 			link.Url += $"#{anchor}";
 
 		return match;
-
-
-
 	}
+
+	private static bool IsCrossLink(Uri? uri) =>
+		uri != null
+		&& !ExcludedSchemes.Contains(uri.Scheme)
+		&& !uri.IsFile
+		&& Path.GetExtension(uri.OriginalString) == ".md";
 }

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

@@ -65,6 +65,12 @@ public void GeneratesHtml() =>
 
 	[Fact]
 	public void HasNoErrors() => Collector.Diagnostics.Should().HaveCount(0);
+
+	[Fact]
+	public void EmitsCrossLink()
+	{
+		Collector.CrossLinks.Should().HaveCount(0);
+	}
 }
 
 public class InsertPageTitleTests(ITestOutputHelper output) : LinkTestBase(output,
@@ -82,4 +88,88 @@ public void GeneratesHtml() =>
 
 	[Fact]
 	public void HasNoErrors() => Collector.Diagnostics.Should().HaveCount(0);
+
+	[Fact]
+	public void EmitsCrossLink()
+	{
+		Collector.CrossLinks.Should().HaveCount(0);
+	}
+}
+
+public class LinkReferenceTest(ITestOutputHelper output) : LinkTestBase(output,
+	"""
+	[test][test]
+
+	[test]: testing/req.md
+	"""
+)
+{
+	[Fact]
+	public void GeneratesHtml() =>
+		// language=html
+		Html.Should().Contain(
+			"""<p><a href="testing/req.html">test</a></p>"""
+		);
+
+	[Fact]
+	public void HasNoErrors() => Collector.Diagnostics.Should().HaveCount(0);
+
+	[Fact]
+	public void EmitsCrossLink()
+	{
+		Collector.CrossLinks.Should().HaveCount(0);
+	}
+}
+
+public class CrossLinkReferenceTest(ITestOutputHelper output) : LinkTestBase(output,
+	"""
+	[test][test]
+
+	[test]: kibana://index.md
+	"""
+)
+{
+	[Fact]
+	public void GeneratesHtml() =>
+		// language=html
+		Html.Should().Contain(
+			// TODO: The link is not rendered correctly yet, will be fixed in a follow-up
+			"""<p><a href="kibana://index.html">test</a></p>"""
+		);
+
+	[Fact]
+	public void HasNoErrors() => Collector.Diagnostics.Should().HaveCount(0);
+
+	[Fact]
+	public void EmitsCrossLink()
+	{
+		Collector.CrossLinks.Should().HaveCount(1);
+		Collector.CrossLinks.Should().Contain("kibana://index.md");
+	}
+}
+
+public class CrossLinkTest(ITestOutputHelper output) : LinkTestBase(output,
+	"""
+
+	Go to [test](kibana://index.md)
+	"""
+)
+{
+	[Fact]
+	public void GeneratesHtml() =>
+		// language=html
+		Html.Should().Contain(
+			// TODO: The link is not rendered correctly yet, will be fixed in a follow-up
+			"""<p>Go to <a href="kibana://index.html">test</a></p>"""
+		);
+
+	[Fact]
+	public void HasNoErrors() => Collector.Diagnostics.Should().HaveCount(0);
+
+	[Fact]
+	public void EmitsCrossLink()
+	{
+		Collector.CrossLinks.Should().HaveCount(1);
+		Collector.CrossLinks.Should().Contain("kibana://index.md");
+	}
 }