fix: update help text to show allowed values from AllowedValues attribute instead of Enum values (#391)

Author: scott-xu

src/CommandLineUtils/HelpText/DefaultHelpTextGenerator.cs

@@ -192,20 +192,28 @@ protected virtual void GenerateArguments(
 
                 foreach (var arg in visibleArguments)
                 {
-                    var enumNames = ExtractNamesFromEnum(arg.UnderlyingType);
-                    var description = enumNames.Any()
-                        ? $"{arg.Description}\nAllowed values are: {string.Join(", ", enumNames)}."
-                        : arg.Description;
+                    var description = arg.Description;
+                    var allowedValuesBeenSet = false;
 
                     foreach (var attributeValidator in arg.Validators.Cast<AttributeValidator>())
                     {
                         if (attributeValidator?.ValidationAttribute is AllowedValuesAttribute allowedValuesAttribute)
                         {
                             description += $"\nAllowed values are: {string.Join(", ", allowedValuesAttribute.AllowedValues)}.";
+                            allowedValuesBeenSet = true;
                             break;
                         }
                     }
 
+                    if (!allowedValuesBeenSet)
+                    {
+                        var enumNames = ExtractNamesFromEnum(arg.UnderlyingType);
+                        if (enumNames.Any())
+                        {
+                            description += $"\nAllowed values are: {string.Join(", ", enumNames)}.";
+                        }
+                    }
+
                     var wrappedDescription = IndentWriter?.Write(description);
                     var message = string.Format(outputFormat, arg.Name, wrappedDescription);
 
@@ -236,20 +244,28 @@ protected virtual void GenerateOptions(
 
                 foreach (var opt in visibleOptions)
                 {
-                    var enumNames = ExtractNamesFromEnum(opt.UnderlyingType);
-                    var description = enumNames.Any()
-                        ? $"{opt.Description}\nAllowed values are: {string.Join(", ", enumNames)}."
-                        : opt.Description;
+                    var description = opt.Description;
+                    var allowedValuesBeenSet = false;
 
                     foreach (var attributeValidator in opt.Validators.Cast<AttributeValidator>())
                     {
                         if (attributeValidator?.ValidationAttribute is AllowedValuesAttribute allowedValuesAttribute)
                         {
                             description += $"\nAllowed values are: {string.Join(", ", allowedValuesAttribute.AllowedValues)}.";
+                            allowedValuesBeenSet = true;
                             break;
                         }
                     }
 
+                    if (!allowedValuesBeenSet)
+                    {
+                        var enumNames = ExtractNamesFromEnum(opt.UnderlyingType);
+                        if (enumNames.Any())
+                        {
+                            description += $"\nAllowed values are: {string.Join(", ", enumNames)}.";
+                        }
+                    }
+
                     var wrappedDescription = IndentWriter?.Write(description);
                     var message = string.Format(outputFormat, Format(opt), wrappedDescription);
 

test/CommandLineUtils.Tests/DefaultHelpTextGeneratorTests.cs

@@ -112,19 +112,23 @@ public void ShowHelp()
             app.Option("--rStrOpt <E>", "restricted str option desc.", CommandOptionType.SingleValue, o => o.IsRequired().Accepts().Values("Foo", "Bar"));
             app.Option<int>("--intOpt <E>", "int option desc.", CommandOptionType.SingleValue);
             app.Option<SomeEnum>("--enumOpt <E>", "enum option desc.", CommandOptionType.SingleValue);
+            app.Option<SomeEnum>("--rEnumOpt <E>", "restricted enum option desc.", CommandOptionType.SingleValue, o => o.Accepts().Values("None", "Normal"));
             app.Argument("SomeStringArgument", "string arg desc.");
             app.Argument("RestrictedStringArgument", "restricted string arg desc.", a => a.IsRequired().Accepts().Values("Foo", "Bar"));
             app.Argument<SomeEnum>("SomeEnumArgument", "enum arg desc.");
+            app.Argument<SomeEnum>("RestrictedEnumArgument", "restricted enum arg desc.", a => a.Accepts().Values("None", "Normal"));
             var helpText = GetHelpText(app);
 
-            Assert.Equal(@"Usage:  [options] <SomeStringArgument> <RestrictedStringArgument> <SomeEnumArgument>
+            Assert.Equal(@"Usage:  [options] <SomeStringArgument> <RestrictedStringArgument> <SomeEnumArgument> <RestrictedEnumArgument>
 
 Arguments:
   SomeStringArgument        string arg desc.
   RestrictedStringArgument  restricted string arg desc.
                             Allowed values are: Foo, Bar.
   SomeEnumArgument          enum arg desc.
                             Allowed values are: None, Normal, Extreme.
+  RestrictedEnumArgument    restricted enum arg desc.
+                            Allowed values are: None, Normal.
 
 Options:
   -?|-h|--help              Show help information.
@@ -134,6 +138,8 @@ SomeEnumArgument          enum arg desc.
   --intOpt <E>              int option desc.
   --enumOpt <E>             enum option desc.
                             Allowed values are: None, Normal, Extreme.
+  --rEnumOpt <E>            restricted enum option desc.
+                            Allowed values are: None, Normal.
 
 ",
             helpText,
@@ -148,14 +154,16 @@ public void ShowHelpFromAttributes()
             app.Conventions.UseDefaultConventions();
             var helpText = GetHelpText(app);
 
-            Assert.Equal(@"Usage: test [options] <SomeStringArgument> <RestrictedStringArgument> <SomeEnumArgument>
+            Assert.Equal(@"Usage: test [options] <SomeStringArgument> <RestrictedStringArgument> <SomeEnumArgument> <RestrictedEnumArgument>
 
 Arguments:
   SomeStringArgument                string arg desc.
   RestrictedStringArgument          restricted string arg desc.
                                     Allowed values are: Foo, Bar.
   SomeEnumArgument                  enum arg desc.
                                     Allowed values are: None, Normal, Extreme.
+  RestrictedEnumArgument            restricted enum arg desc.
+                                    Allowed values are: None, Normal.
 
 Options:
   -strOpt|--str-opt <STR_OPT>       str option desc.
@@ -164,6 +172,8 @@ SomeEnumArgument                  enum arg desc.
   -intOpt|--int-opt <INT_OPT>       int option desc.
   -enumOpt|--verbosity <VERBOSITY>  enum option desc.
                                     Allowed values are: None, Normal, Extreme.
+  -rEnumOpt|--verb2 <VERB2>         restricted enum option desc.
+                                    Allowed values are: None, Normal.
   -?|-h|--help                      Show help information.
 
 ",
@@ -187,6 +197,10 @@ public class MyApp
             [Option(ShortName = "enumOpt", Description = "enum option desc.")]
             public SomeEnum Verbosity { get; set; }
 
+            [Option(ShortName = "rEnumOpt", Description = "restricted enum option desc.")]
+            [AllowedValues("None", "Normal")]
+            public SomeEnum Verb2 { get; set; }
+
             [Argument(0, Description = "string arg desc.")]
             public string SomeStringArgument { get; set; }
 
@@ -197,6 +211,10 @@ public class MyApp
 
             [Argument(2, Description = "enum arg desc.")]
             public SomeEnum SomeEnumArgument { get; set; }
+
+            [Argument(3, Description = "restricted enum arg desc.")]
+            [AllowedValues("None", "Normal")]
+            public SomeEnum RestrictedEnumArgument { get; set; }
         }
 
         [Theory]