clear output directory before generations

src/Doki.Output.Abstractions/IOutput.cs

@@ -5,6 +5,10 @@
 /// </summary>
 public interface IOutput
 {
+    Task BeginAsync(CancellationToken cancellationToken = default) => Task.CompletedTask;
+
+    Task EndAsync(CancellationToken cancellationToken = default) => Task.CompletedTask;
+
     /// <summary>
     /// Writes the content list to the output.
     /// </summary>

src/Doki.Output.Abstractions/OutputOptions.cs

@@ -6,4 +6,6 @@ namespace Doki.Output;
 public record OutputOptions<T> where T : IOutput
 {
     [JsonPropertyName("outputPath")] public DirectoryInfo OutputDirectory { get; init; } = null!;
+
+    [JsonPropertyName("clearOutput")] public bool ClearOutput { get; init; } = true;
 }

src/Doki.Output.Abstractions/OutputOptionsExtensions.cs

@@ -0,0 +1,14 @@
+namespace Doki.Output;
+
+public static class OutputOptionsExtensions
+{
+    public static void ClearOutputDirectoryIfRequired<T>(this OutputOptions<T> options) where T : IOutput
+    {
+        ArgumentNullException.ThrowIfNull(options);
+
+        if (options is { ClearOutput: true, OutputDirectory.Exists: true })
+        {
+            options.OutputDirectory.Delete(true);
+        }
+    }
+}

src/Doki.Output.ClassLibrary/ClassLibraryOutput.cs

@@ -2,6 +2,13 @@
 
 public sealed class ClassLibraryOutput(ClassLibraryOutputOptions options) : IOutput
 {
+    public Task BeginAsync(CancellationToken cancellationToken = default)
+    {
+        options.ClearOutputDirectoryIfRequired();
+
+        return Task.CompletedTask;
+    }
+
     public async Task WriteAsync(ContentList contentList, CancellationToken cancellationToken = default)
     {
         ArgumentNullException.ThrowIfNull(contentList);

src/Doki.Output.Markdown/MarkdownOutput.cs

@@ -5,6 +5,13 @@ namespace Doki.Output.Markdown;
 
 public sealed class MarkdownOutput(OutputOptions<MarkdownOutput> options) : IOutput
 {
+    public Task BeginAsync(CancellationToken cancellationToken = default)
+    {
+        options.ClearOutputDirectoryIfRequired();
+
+        return Task.CompletedTask;
+    }
+
     public async Task WriteAsync(ContentList contentList, CancellationToken cancellationToken = default)
     {
         ArgumentNullException.ThrowIfNull(contentList);

src/Doki/DocumentationGenerator.cs

@@ -154,6 +154,11 @@ public async Task GenerateAsync(ILogger logger, CancellationToken cancellationTo
 
         logger.LogInformation("Generating documentation for {AssemblyCount} assemblies.", _assemblies.Count);
 
+        foreach (var output in outputs)
+        {
+            await output.BeginAsync(cancellationToken);
+        }
+
         var assemblies = new ContentList
         {
             Id = ContentList.Assemblies,
@@ -184,6 +189,11 @@ await GenerateAssemblyDocumentationAsync(new GeneratorContext<Assembly>
         {
             await output.WriteAsync(assemblies, cancellationToken);
         }
+
+        foreach (var output in outputs)
+        {
+            await output.EndAsync(cancellationToken);
+        }
     }
 
     private async Task<AssemblyDocumentation?> GenerateAssemblyDocumentationAsync(GeneratorContext<Assembly> context,