avoid some alloc in config reading

src/ConfigReader/ConfigResult.cs

@@ -1,19 +1,19 @@
 public class ConfigResult
 {
-    public bool? ReadOnly;
-    public bool ValidateContent;
-    public bool OmitSnippetLinks;
-    public LinkFormat LinkFormat;
-    public DocumentConvention Convention;
-    public int TocLevel;
-    public int MaxWidth;
-    public List<string> UrlsAsSnippets = [];
-    public List<string> ExcludeDirectories = [];
-    public List<string> ExcludeMarkdownDirectories = [];
-    public List<string> ExcludeSnippetDirectories = [];
-    public bool? WriteHeader;
-    public string? Header;
-    public string? UrlPrefix;
-    public List<string> TocExcludes = [];
-    public bool TreatMissingAsWarning;
+    public bool? ReadOnly { get; init; }
+    public bool ValidateContent { get; init; }
+    public bool OmitSnippetLinks { get; init; }
+    public LinkFormat LinkFormat { get; init; }
+    public DocumentConvention Convention { get; init; }
+    public int TocLevel { get; init; }
+    public int MaxWidth { get; init; }
+    public List<string>? UrlsAsSnippets { get; init; }
+    public List<string>? ExcludeDirectories { get; init; }
+    public List<string>? ExcludeMarkdownDirectories { get; init; }
+    public List<string>? ExcludeSnippetDirectories { get; init; }
+    public bool? WriteHeader { get; init; }
+    public string? Header { get; init; }
+    public string? UrlPrefix { get; init; }
+    public List<string>? TocExcludes { get; init; }
+    public bool TreatMissingAsWarning { get; init; }
 }

src/ConfigReader/ExcludeToFilterBuilder.cs

@@ -1,13 +1,19 @@
 static class ExcludeToFilterBuilder
 {
-    public static ShouldIncludeDirectory ExcludesToFilter(List<string> excludes) =>
+    public static ShouldIncludeDirectory ExcludesToFilter(List<string>? excludes) =>
         path =>
         {
             if (DefaultDirectoryExclusions.ShouldExcludeDirectory(path))
             {
                 return false;
             }
 
+            if(excludes == null ||
+               excludes.Count == 0)
+            {
+                return false;
+            }
+
             if (!excludes.Any(path.Contains))
             {
                 return true;

src/ConfigReader/LogBuilder.cs

@@ -37,53 +37,58 @@ public static string BuildConfigLogMessage(string targetDirectory, ConfigResult
                 $"    MaxWidth: {maxWidth}");
         }
 
-        if (config.ExcludeDirectories.Count != 0)
+        var excludeDirectories = config.ExcludeDirectories;
+        if (excludeDirectories != null && excludeDirectories.Count != 0)
         {
             Polyfill.AppendLine(
                 builder,
                 $"""
                      ExcludeDirectories:
-                         {string.Join("\r\n        ", config.ExcludeDirectories)}
+                         {string.Join("\r\n        ", excludeDirectories)}
                  """);
         }
 
-        if (config.ExcludeMarkdownDirectories.Count != 0)
+        var excludeMarkdownDirectories = config.ExcludeMarkdownDirectories;
+        if (excludeMarkdownDirectories != null && excludeMarkdownDirectories.Count != 0)
         {
             Polyfill.AppendLine(
                 builder,
                 $"""
                      ExcludeMarkdownDirectories:
-                         {string.Join("\r\n        ", config.ExcludeMarkdownDirectories)}
+                         {string.Join("\r\n        ", excludeMarkdownDirectories)}
                  """);
         }
 
-        if (config.ExcludeSnippetDirectories.Count != 0)
+        var excludeSnippetDirectories = config.ExcludeSnippetDirectories;
+        if (excludeSnippetDirectories != null && excludeSnippetDirectories.Count != 0)
         {
             Polyfill.AppendLine(
                 builder,
                 $"""
                      ExcludeSnippetDirectories:
-                         {string.Join("\r\n        ", config.ExcludeSnippetDirectories)}
+                         {string.Join("\r\n        ", excludeSnippetDirectories)}
                  """);
         }
 
-        if (config.TocExcludes.Count != 0)
+        var tocExcludes = config.TocExcludes;
+        if (tocExcludes != null && tocExcludes.Count != 0)
         {
             Polyfill.AppendLine(
                 builder,
                 $"""
                      TocExcludes:
-                         {string.Join("\r\n        ", config.TocExcludes)}
+                         {string.Join("\r\n        ", tocExcludes)}
                  """);
         }
 
-        if (config.UrlsAsSnippets.Count != 0)
+        var urlsAsSnippets = config.UrlsAsSnippets;
+        if (urlsAsSnippets != null && urlsAsSnippets.Count != 0)
         {
             Polyfill.AppendLine(
                 builder,
                 $"""
                      UrlsAsSnippets:
-                         {string.Join("\r\n        ", config.UrlsAsSnippets)}
+                         {string.Join("\r\n        ", urlsAsSnippets)}
                  """);
         }
 

src/MarkdownSnippets.MsBuild/DocoTask.cs

@@ -78,7 +78,12 @@ public override bool Execute()
         try
         {
             var snippets = new List<Snippet>();
-            snippets.AppendUrlsAsSnippets(configResult.UrlsAsSnippets).GetAwaiter().GetResult();
+            var urlsAsSnippets = configResult.UrlsAsSnippets;
+            if (urlsAsSnippets != null)
+            {
+                snippets.AppendUrlsAsSnippets(urlsAsSnippets).GetAwaiter().GetResult();
+            }
+
             processor.AddSnippets(snippets);
             var snippetsInError = processor.Snippets.Where(_ => _.IsInError).ToList();
             if (snippetsInError.Any())

src/MarkdownSnippets.Tool/Program.cs

@@ -52,11 +52,12 @@ static async Task Inner(string targetDirectory, ConfigInput configInput)
         validateContent: configResult.ValidateContent,
         omitSnippetLinks: configResult.OmitSnippetLinks);
 
-    if (configResult.UrlsAsSnippets.Count != 0)
+    var urlsAsSnippets = configResult.UrlsAsSnippets;
+    if (urlsAsSnippets != null && urlsAsSnippets.Count != 0)
     {
         var snippets = new List<Snippet>();
 
-        await snippets.AppendUrlsAsSnippets(configResult.UrlsAsSnippets);
+        await snippets.AppendUrlsAsSnippets(urlsAsSnippets);
         processor.AddSnippets(snippets);
     }