fix: array options not bound to command line args (dotnet#8784)

src/docfx/Extensions/ArrayOptionConverter.cs

@@ -0,0 +1,25 @@
+// Copyright (c) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+using System.ComponentModel;
+using System.Globalization;
+
+namespace Microsoft.DocAsCode;
+
+internal class ArrayOptionConverter : TypeConverter
+{
+    public override object ConvertTo(ITypeDescriptorContext context, CultureInfo culture, object value, Type destinationType)
+    {
+        return value is string && (destinationType == typeof(IEnumerable<string>) || destinationType == typeof(string[]));
+    }
+
+    public override object ConvertFrom(ITypeDescriptorContext context, CultureInfo culture, object value)
+    {
+        if (value is string str)
+        {
+            return str.Split(',', StringSplitOptions.RemoveEmptyEntries);
+        }
+
+        return base.ConvertFrom(context, culture, value);
+    }
+}

src/docfx/Models/BuildCommandOptions.cs

@@ -19,14 +19,17 @@ internal class BuildCommandOptions : LogOptions
 
     [Description("Specify the urls of xrefmap used by content files.")]
     [CommandOption("-x|--xref")]
+    [TypeConverter(typeof(ArrayOptionConverter))]
     public IEnumerable<string> XRefMaps { get; set; }
 
     [Description("Specify the template name to apply to. If not specified, output YAML file will not be transformed.")]
     [CommandOption("-t|--template")]
+    [TypeConverter(typeof(ArrayOptionConverter))]
     public IEnumerable<string> Templates { get; set; }
 
     [Description("Specify which theme to use. By default 'default' theme is offered.")]
     [CommandOption("--theme")]
+    [TypeConverter(typeof(ArrayOptionConverter))]
     public IEnumerable<string> Themes { get; set; }
 
     [Description("Host the generated documentation to a website")]
@@ -79,6 +82,7 @@ internal class BuildCommandOptions : LogOptions
 
     [Description("Set the order of post processors in plugins")]
     [CommandOption("--postProcessors")]
+    [TypeConverter(typeof(ArrayOptionConverter))]
     public IEnumerable<string> PostProcessors { get; set; }
 
     [Description("If set to true, docfx does not dereference (aka. copy) file to the output folder, instead, it saves a link_to_path property inside mainfiest.json to indicate the physical location of that file.")]

src/docfx/Models/PdfCommandOptions.cs

@@ -51,6 +51,7 @@ internal class PdfCommandOptions : BuildCommandOptions
 
     [Description("Specify the toc files to be excluded")]
     [CommandOption("--excludedTocs")]
+    [TypeConverter(typeof(ArrayOptionConverter))]
     public IEnumerable<string> ExcludedTocs { get; set; }
 
     [Description("Specify the base path to generate external link, {host}/{locale}/{basePath}")]