Keep default values out of global option help

src/Repl.Core/Help/HelpTextBuilder.Rendering.cs

@@ -316,7 +316,27 @@ private static Type UnwrapAsyncReturnType(Type returnType)
 
 	private static bool IsDefaultForType(object value, Type type)
 	{
-		return ParsingOptions.IsDefaultForType(value, type);
+		if (type == typeof(bool))
+		{
+			return value is false;
+		}
+
+		if (type == typeof(int))
+		{
+			return value is 0;
+		}
+
+		if (type == typeof(long))
+		{
+			return value is 0L;
+		}
+
+		if (type == typeof(double))
+		{
+			return value is 0.0d;
+		}
+
+		return false;
 	}
 
 	private static string ResolveOptionPlaceholder(Type parameterType)
@@ -605,10 +625,6 @@ private static string[][] BuildGlobalOptionRows(ParsingOptions parsingOptions)
 				var description = string.IsNullOrWhiteSpace(option.Description)
 					? "Custom global option."
 					: option.Description;
-				if (!string.IsNullOrWhiteSpace(option.DefaultValue))
-				{
-					description = $"{description} [default: {option.DefaultValue}]";
-				}
 
 				return new[]
 				{

src/Repl.IntegrationTests/Given_CustomGlobalOptions.cs

@@ -51,8 +51,8 @@ public void When_RequestingRootHelp_Then_CustomGlobalOptionIsListedInGlobalOptio
 	}
 
 	[TestMethod]
-	[Description("Regression guard: verifies typed global option descriptions and defaults are rendered in root help.")]
-	public void When_RequestingRootHelpForTypedGlobalOptions_Then_DescriptionsAndDefaultsAreListed()
+	[Description("Regression guard: verifies typed global option descriptions are rendered in root help without adding default-value display.")]
+	public void When_RequestingRootHelpForTypedGlobalOptions_Then_DescriptionsAreListed()
 	{
 		var sut = ReplApp.Create()
 			.UseGlobalOptions<DemoGlobals>();
@@ -62,10 +62,10 @@ public void When_RequestingRootHelpForTypedGlobalOptions_Then_DescriptionsAndDef
 
 		output.ExitCode.Should().Be(0);
 		output.Text.Should().Contain("--tenant, -t");
-		output.Text.Should().Contain("Tenant id used for all commands. [default: default]");
+		output.Text.Should().Contain("Tenant id used for all commands.");
 		output.Text.Should().Contain("--verbose, -v");
 		output.Text.Should().Contain("Enable verbose diagnostics for all commands.");
-		output.Text.Should().NotContain("Enable verbose diagnostics for all commands. [default: False]");
+		output.Text.Should().NotContain("[default:");
 	}
 
 	[TestMethod]
@@ -76,15 +76,15 @@ public void When_RequestingRootHelpForExplicitGlobalOption_Then_DescriptionIsLis
 			.Options(options => options.Parsing.AddGlobalOption<string>(
 				"tenant",
 				description: "Tenant id used for all commands.",
-				aliases: ["-t"],
-				defaultValue: "default"));
+				aliases: ["-t"]));
 		sut.Map("ping", () => "ok");
 
 		var output = ConsoleCaptureHelper.Capture(() => sut.Run(["--help", "--no-logo"]));
 
 		output.ExitCode.Should().Be(0);
 		output.Text.Should().Contain("--tenant, -t");
-		output.Text.Should().Contain("Tenant id used for all commands. [default: default]");
+		output.Text.Should().Contain("Tenant id used for all commands.");
+		output.Text.Should().NotContain("[default:");
 	}
 
 	private sealed class DemoGlobals

src/Repl.Tests/Given_GlobalOptionsAccessor.cs

@@ -67,6 +67,30 @@ public void When_OptionNotProvidedButRegisteredDefault_Then_GetValueReturnsRegis
 		sut.GetValue<int>("port").Should().Be(3000);
 	}
 
+	[TestMethod]
+	[Description("GetValue returns caller default when a value-typed option has no explicit registration default.")]
+	public void When_ValueTypeOptionNotProvidedAndNoRegisteredDefault_Then_GetValueReturnsCallerDefault()
+	{
+		var parsing = new ParsingOptions();
+		parsing.AddGlobalOption<int>("port");
+		var sut = new GlobalOptionsSnapshot(parsing);
+		sut.Update(new Dictionary<string, IReadOnlyList<string>>(StringComparer.OrdinalIgnoreCase));
+
+		sut.GetValue<int>("port", 8080).Should().Be(8080);
+	}
+
+	[TestMethod]
+	[Description("GetValue returns caller default when a described value-typed option has no explicit registration default.")]
+	public void When_DescribedValueTypeOptionNotProvidedAndNoRegisteredDefault_Then_GetValueReturnsCallerDefault()
+	{
+		var parsing = new ParsingOptions();
+		parsing.AddGlobalOption<int>("port", "Port used by the server.");
+		var sut = new GlobalOptionsSnapshot(parsing);
+		sut.Update(new Dictionary<string, IReadOnlyList<string>>(StringComparer.OrdinalIgnoreCase));
+
+		sut.GetValue<int>("port", 8080).Should().Be(8080);
+	}
+
 	[TestMethod]
 	[Description("HasValue returns false before parsing.")]
 	public void When_NeverUpdated_Then_HasValueReturnsFalse()