Fix enum error message to apply to global options

Author: dusrdev

src/ConsoleAppFramework/Command.cs

@@ -255,7 +255,7 @@ string Core(ITypeSymbol type, bool nullable)
                     if (type.TypeKind == TypeKind.Enum)
                     {
                         string typeName = type.ToDisplayString(SymbolDisplayFormat.FullyQualifiedFormat);
-                        return $"if ({incrementIndex}!Enum.TryParse<{typeName}>(commandArgs[i], true, {outArgVar})) {{ ThrowArgumentParseFailed<{typeName}>(\"{argumentName}\", commandArgs[i]); }}{elseExpr}";
+                        return $"if ({incrementIndex}!Enum.TryParse<{typeName}>(commandArgs[i], true, {outArgVar})) {{ ThrowArgumentParseFailedEnum(typeof({typeName}), \"{argumentName}\", commandArgs[i]); }}{elseExpr}";
                     }
 
                     // ParamsArray

src/ConsoleAppFramework/ConsoleAppBaseCode.cs

@@ -257,8 +257,9 @@ static void ThrowArgumentParseFailed(string argumentName, string value)
         throw new ArgumentParseFailedException($"Argument '{argumentName}' failed to parse, provided value: {value}");
     }
 
-    static void ThrowArgumentParseFailed<TEnum>(string argumentName, string value) where TEnum : struct, Enum {
-        var values = string.Join(", ", Enum.GetNames<TEnum>());
+    static void ThrowArgumentParseFailedEnum(Type enumType, string argumentName, string value)
+    {
+        var values = string.Join(", ", Enum.GetNames(enumType));
         throw new ArgumentParseFailedException($"Argument '{argumentName}' is invalid. Provided value: {value}. Valid values: {values}");
     }
 
@@ -747,6 +748,11 @@ static T ParseArgument<T>(ref ReadOnlyMemory<string> args, int i)
                         return value;
                     }
 
+                    if (typeof(T).IsEnum)
+                    {
+                        ThrowArgumentParseFailedEnum(typeof(T), args.Span[i], args.Span[i + 1]);
+                    }
+
                     ThrowArgumentParseFailed(args.Span[i], args.Span[i + 1]);
                 }
                 else

tests/ConsoleAppFramework.GeneratorTests/GlobalOptionTest.cs

@@ -85,6 +85,32 @@ enum Fruit
 """, "--parameter 100 --x 10 --dry-run --y 20 --fruit grape", "(100, True, Grape) -> (10, 20)");
     }
 
+    [Test]
+    public async Task EnumErrorShowsValidValues()
+    {
+        var result = verifier.Error("""
+ConsoleApp.Log = x => Console.Write(x);
+
+var app = ConsoleApp.Create();
+app.ConfigureGlobalOptions((ref ConsoleApp.GlobalOptionsBuilder builder) =>
+{
+    var fruit = builder.AddGlobalOption("--fruit", "", Fruit.Apple);
+    return fruit;
+});
+
+app.Add("", (ConsoleAppContext context) => { });
+app.Run(args);
+
+enum Fruit
+{
+    Orange, Apple, Grape
+}
+""", "--fruit Potato");
+
+        await Assert.That(result.Stdout).Contains("Argument '--fruit' is invalid. Provided value: Potato. Valid values: Orange, Apple, Grape");
+        await Assert.That(result.ExitCode).IsEqualTo(1);
+    }
+
     [Test]
     public async Task DefaultValueForOption()
     {