Fix DiagnosticsCollector API to be a bit cleaner

src/Elastic.Markdown/Diagnostics/DiagnosticsChannel.cs

@@ -41,7 +41,6 @@ public void Write(Diagnostic diagnostic)
 	}
 }
 
-
 public enum Severity { Error, Warning }
 
 public readonly record struct Diagnostic
@@ -70,7 +69,6 @@ public void Write(Diagnostic diagnostic)
 	}
 }
 
-
 public class DiagnosticsCollector(ILoggerFactory loggerFactory, IReadOnlyCollection<IDiagnosticsOutput> outputs)
 	: IHostedService
 {
@@ -84,24 +82,32 @@ public class DiagnosticsCollector(ILoggerFactory loggerFactory, IReadOnlyCollect
 	public long Warnings => _warnings;
 	public long Errors => _errors;
 
+	private Task? _started;
+
 	public HashSet<string> OffendingFiles { get; } = new();
 
-	public async Task StartAsync(Cancel ctx)
+	public Task StartAsync(Cancel ctx)
 	{
-		await Channel.WaitToWrite();
-		while (!Channel.CancellationToken.IsCancellationRequested)
+		if (_started is not null) return _started;
+		_started = Task.Run(async () =>
 		{
-			try
-			{
-				while (await Channel.Reader.WaitToReadAsync(Channel.CancellationToken))
-					Drain();
-			}
-			catch
+			await Channel.WaitToWrite();
+			while (!Channel.CancellationToken.IsCancellationRequested)
 			{
-				//ignore
+				try
+				{
+					while (await Channel.Reader.WaitToReadAsync(Channel.CancellationToken))
+						Drain();
+				}
+				catch
+				{
+					//ignore
+				}
 			}
-		}
-		Drain();
+
+			Drain();
+		}, ctx);
+		return _started;
 
 		void Drain()
 		{
@@ -124,7 +130,12 @@ private void IncrementSeverityCount(Diagnostic item)
 			Interlocked.Increment(ref _warnings);
 	}
 
-	protected virtual void HandleItem(Diagnostic diagnostic) {}
+	protected virtual void HandleItem(Diagnostic diagnostic) { }
 
-	public virtual Task StopAsync(CancellationToken cancellationToken) => Task.CompletedTask;
+	public virtual async Task StopAsync(CancellationToken cancellationToken)
+	{
+		if (_started is not null)
+			await _started;
+		await Channel.Reader.Completion;
+	}
 }

src/Elastic.Markdown/DocumentationGenerator.cs

@@ -97,7 +97,7 @@ public async Task GenerateAll(Cancel ctx)
 
 		var handledItems = 0;
 
-		var collectTask =  Task.Run(async () => await Context.Collector.StartAsync(ctx), ctx);
+		_ = Context.Collector.StartAsync(ctx);
 
 		await Parallel.ForEachAsync(DocumentationSet.Files, ctx, async (file, token) =>
 		{
@@ -126,11 +126,8 @@ await Parallel.ForEachAsync(DocumentationSet.Files, ctx, async (file, token) =>
 
 		await GenerateDocumentationState(ctx);
 
-		await collectTask;
-		await Context.Collector.Channel.Reader.Completion;
 		await Context.Collector.StopAsync(ctx);
 
-
 		IFileInfo OutputFile(string relativePath)
 		{
 			var outputFile = _writeFileSystem.FileInfo.New(Path.Combine(DocumentationSet.OutputPath.FullName, relativePath));

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

@@ -76,6 +76,10 @@ public override bool Match(InlineProcessor processor, ref StringSlice slice)
 			var pathOnDisk = Path.Combine(includeFrom, url.TrimStart('/'));
 			if (!context.Build.ReadFileSystem.File.Exists(pathOnDisk))
 				processor.EmitError(line, column, length, $"`{url}` does not exist. resolved to `{pathOnDisk}");
+			else
+			{
+
+			}
 		}
 		else
 			link.Url = "";

tests/Elastic.Markdown.Tests/Directives/AdmonitionTests.cs

@@ -41,6 +41,12 @@ public class TipTests(ITestOutputHelper output) : AdmonitionTests(output, "tip")
 	public void SetsTitle() => Block!.Title.Should().Be("Tip");
 }
 
+public class AttentionTests(ITestOutputHelper output) : AdmonitionTests(output, "attention")
+{
+	[Fact]
+	public void SetsTitle() => Block!.Title.Should().Be("Attention");
+}
+
 public class NoteTitleTests(ITestOutputHelper output) : DirectiveTest<AdmonitionBlock>(output,
 """
 ```{note} This is my custom note

tests/Elastic.Markdown.Tests/Directives/AdmonitionUnsupportedTests.cs

@@ -26,7 +26,6 @@ A regular paragraph.
 }
 
 // ReSharper disable UnusedType.Global
-public class AttentionTests(ITestOutputHelper output) : AdmonitionUnsupportedTests(output, "attention");
 public class DangerTests(ITestOutputHelper output) : AdmonitionUnsupportedTests(output, "danger");
 public class ErrorTests(ITestOutputHelper output) : AdmonitionUnsupportedTests(output, "error");
 public class HintTests(ITestOutputHelper output) : AdmonitionUnsupportedTests(output, "hint");

tests/Elastic.Markdown.Tests/Directives/DirectiveBaseTests.cs

@@ -86,14 +86,12 @@ protected virtual void AddToFileSystem(MockFileSystem fileSystem) { }
 
 	public virtual async Task InitializeAsync()
 	{
-		var collectTask =  Task.Run(async () => await Collector.StartAsync(default), default);
+		_ = Collector.StartAsync(default);
 
 		Document = await File.ParseFullAsync(default);
 		Html = File.CreateHtml(Document);
 		Collector.Channel.TryComplete();
 
-		await collectTask;
-		await Collector.Channel.Reader.Completion;
 		await Collector.StopAsync(default);
 	}
 

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

@@ -96,16 +96,14 @@ protected virtual void AddToFileSystem(MockFileSystem fileSystem) { }
 
 	public virtual async Task InitializeAsync()
 	{
-		var collectTask =  Task.Run(async () => await Collector.StartAsync(default), default);
+		_ = Collector.StartAsync(default);
 
 		await Set.ResolveDirectoryTree(default);
 
 		Document = await File.ParseFullAsync(default);
 		Html = File.CreateHtml(Document);
 		Collector.Channel.TryComplete();
 
-		await collectTask;
-		await Collector.Channel.Reader.Completion;
 		await Collector.StopAsync(default);
 	}