* Use a single point of truth (CmdLineExtensions.GetCommandLineFields) to determine which fields are used: non-static, no [Ignore] attribute, and ordered by base type first

* Static field in Test1.cs no longer needs [Ignore] because of that
* Some more minor code cleanup

Author: Timwi

Src/CmdLineExtensions.cs

@@ -8,11 +8,8 @@ namespace RT.CommandLine;
 
 static class CmdLineExtensions
 {
-    public static string[] GetOrderedOptionAttributeNames(this MemberInfo member)
-    {
-        var attr = member.GetCustomAttributes<OptionAttribute>().FirstOrDefault();
-        return attr == null ? null : attr.Names.OrderBy(compareOptionNames).ToArray();
-    }
+    public static string[] GetOrderedOptionAttributeNames(this MemberInfo member) =>
+        member.GetCustomAttributes<OptionAttribute>().FirstOrDefault()?.Names.OrderBy(compareOptionNames).ToArray();
 
     private static int compareOptionNames(string opt1, string opt2)
     {
@@ -70,4 +67,9 @@ public static ConsoleColoredString FormatParameterUsage(this FieldInfo field, bo
             field.GetOrderedOptionAttributeNames().First().Color(CmdLineColor.Option),
             "<".Color(CmdLineColor.FieldBrackets) + field.Name.Color(CmdLineColor.Field) + ">".Color(CmdLineColor.FieldBrackets));
     }
+
+    public static IEnumerable<FieldInfo> GetCommandLineFields(this Type type) =>
+        type.GetFields(BindingFlags.Instance | BindingFlags.NonPublic | BindingFlags.Public)
+            .Where(f => !f.IsDefined<IgnoreAttribute>())
+            .OrderBy(f => f.DeclaringType.SelectChain(t => t.BaseType).Count());
 }

Src/CommandLine.cs

@@ -219,11 +219,8 @@ private static object parseCommandLine(string[] args, Type type, int i, Func<Con
         FieldInfo swallowingField = null;
         var haveSeenOptionalPositional = false;
 
-        foreach (var field in type.GetFields())
+        foreach (var field in type.GetCommandLineFields())
         {
-            if (field.IsDefined<IgnoreAttribute>())
-                continue;
-
             var positional = field.IsDefined<IsPositionalAttribute>();
             var option = field.GetCustomAttributes<OptionAttribute>().FirstOrDefault();
             var mandatory = field.IsDefined<IsMandatoryAttribute>();
@@ -745,11 +742,13 @@ private static void getFieldsForHelp(Type type, out List<FieldInfo> optionalOpti
         optionalPositional = [];
         mandatoryPositional = [];
 
-        foreach (var field in type.GetFields().Where(f => !f.IsDefined<UndocumentedAttribute>() && !f.IsDefined<IgnoreAttribute>()))
-            (field.IsDefined<IsMandatoryAttribute>()
+        foreach (var field in type.GetCommandLineFields().Where(f => !f.IsDefined<UndocumentedAttribute>()))
+        {
+            var fieldInfos = field.IsDefined<IsMandatoryAttribute>()
                 ? (field.IsDefined<IsPositionalAttribute>() ? mandatoryPositional : mandatoryOptions)
-                : (field.IsDefined<IsPositionalAttribute>() ? optionalPositional : optionalOptions)
-            ).Add(field);
+                : (field.IsDefined<IsPositionalAttribute>() ? optionalPositional : optionalOptions);
+            fieldInfos.Add(field);
+        }
     }
 
     private static ConsoleColoredString getDocumentation(MemberInfo member, Func<ConsoleColoredString, ConsoleColoredString> helpProcessor) =>
@@ -794,11 +793,8 @@ private static void postBuildStep(IPostBuildReporter rep, Type commandLineType,
 
         checkDocumentation(rep, commandLineType, classDocRecommended);
 
-        foreach (var field in commandLineType.GetFields())
+        foreach (var field in commandLineType.GetCommandLineFields())
         {
-            if (field.IsDefined<IgnoreAttribute>())
-                continue;
-
             if (lastField != null)
                 rep.Error($"The type of {lastField.DeclaringType.FullName}.{lastField.Name} necessitates that it is the last one in the class.", "class " + commandLineType.Name, field.Name);
 
@@ -876,7 +872,7 @@ private static void postBuildStep(IPostBuildReporter rep, Type commandLineType,
                     {
                         // check that the non-default enum values’ Options are present and do not clash
                         var optionNames = enumField.GetOrderedOptionAttributeNames();
-                        if (optionNames == null || !optionNames.Any())
+                        if (optionNames == null || optionNames.Length > 0)
                             rep.Error($"{field.FieldType.FullName}.{enumField.Name} (used by {commandLineType.FullName}.{field.Name}): Enum value must have an [Option] attribute with at least one option name (unless it is the field's default value and the field is optional).", "enum " + field.FieldType.Name, enumField.Name);
                         else
                             checkOptionsUnique(rep, optionNames, optionTaken, commandLineType, field, enumField);

Tests/Test1.cs

@@ -12,7 +12,6 @@ class Test1Cmd : ICommandLineValidatable
     [IsPositional, IsMandatory]
     public Test1SubcommandBase Subcommand;
 
-    [Ignore]
     public static int ValidateCalled = 0;
 
     public ConsoleColoredString Validate()