From 465f9e5d8eec0e83e6e6bb05f1e9c00e15eab062 Mon Sep 17 00:00:00 2001
From: Kevin B <Keboo@users.noreply.github.com>
Date: Mon, 15 Feb 2021 16:30:15 -0800
Subject: [PATCH] Making argument internal to option (#1148)

* WIP making argument internal to option

* Fixing NRT warning

* Fixing end to end test app

* Updating tests
---
 .../Perf_Parser_CustomScenarios.cs            |   5 +-
 .../Perf_Parser_Directives_Suggest.cs         |  16 +-
 .../CommandLine/Perf_Parser_Options_Bare.cs   |   8 +-
 .../Perf_Parser_Options_With_Arguments.cs     |   8 +-
 .../CommandLine/Perf_Suggestions.cs           |  10 +-
 .../ConfigureFromMethodTests.cs               |   2 +-
 .../CommandLine.cs                            |  20 +-
 .../HostingTests.cs                           |   5 +-
 .../EndToEndTestApp/Program.cs                |  20 +-
 src/System.CommandLine.Tests/ArgumentTests.cs |  21 +-
 .../Binding/ModelBinderTests.cs               |  80 +---
 .../ModelBindingCommandHandlerTests.cs        |  73 +---
 .../Binding/TypeConversionTests.cs            | 218 ++--------
 src/System.CommandLine.Tests/CommandTests.cs  |   8 +-
 .../Help/HelpBuilderTests.Approval.cs         |  35 +-
 .../Help/HelpBuilderTests.cs                  |  74 +---
 .../Invocation/CommandHandlerTests.cs         | 122 +-----
 src/System.CommandLine.Tests/OptionTests.cs   |  64 +--
 .../ParseDiagramTests.cs                      |  28 +-
 .../ParserTests.MultipleArguments.cs          |   5 +-
 .../ParserTests.MultiplePositions.cs          |  15 +-
 src/System.CommandLine.Tests/ParserTests.cs   | 401 +++---------------
 .../ParsingValidationTests.cs                 |  67 +--
 .../ResponseFileTests.cs                      |  38 +-
 .../SuggestDirectiveTests.cs                  |   5 +-
 .../SuggestionTests.cs                        | 238 +++--------
 .../SymbolResultTests.cs                      |  10 +-
 src/System.CommandLine/Argument.cs            |   4 +-
 src/System.CommandLine/Help/HelpOption.cs     |   4 +-
 src/System.CommandLine/Option.cs              |  89 +++-
 src/System.CommandLine/Option{T}.cs           |  73 ++--
 31 files changed, 416 insertions(+), 1350 deletions(-)

diff --git a/src/System.CommandLine.Benchmarks/CommandLine/Perf_Parser_CustomScenarios.cs b/src/System.CommandLine.Benchmarks/CommandLine/Perf_Parser_CustomScenarios.cs
index 942471f05..74d9215db 100644
--- a/src/System.CommandLine.Benchmarks/CommandLine/Perf_Parser_CustomScenarios.cs
+++ b/src/System.CommandLine.Benchmarks/CommandLine/Perf_Parser_CustomScenarios.cs
@@ -20,10 +20,7 @@ public void SetupOneOptWithNestedCommand()
         {
             var rootCommand = new Command("root_command");
             var nestedCommand = new Command("nested_command");
-            var option = new Option("-opt1")
-            {
-                Argument = new Argument<int>(() => 123)
-            };
+            var option = new Option<int>("-opt1", () => 123);
             nestedCommand.AddOption(option);
             rootCommand.AddCommand(nestedCommand);
 
diff --git a/src/System.CommandLine.Benchmarks/CommandLine/Perf_Parser_Directives_Suggest.cs b/src/System.CommandLine.Benchmarks/CommandLine/Perf_Parser_Directives_Suggest.cs
index 257e4aeb0..c3a0e2b9d 100644
--- a/src/System.CommandLine.Benchmarks/CommandLine/Perf_Parser_Directives_Suggest.cs
+++ b/src/System.CommandLine.Benchmarks/CommandLine/Perf_Parser_Directives_Suggest.cs
@@ -26,20 +26,8 @@ public void Setup()
 
             var eatCommand = new Command("eat")
             {
-                new Option("--fruit")
-                {
-                    Argument = new Argument<string>()
-                    {
-                        Suggestions = {"apple", "banana", "cherry" }
-                    }
-                },
-                new Option("--vegetable")
-                {
-                    Argument = new Argument<string>()
-                    {
-                        Suggestions = {"asparagus", "broccoli", "carrot" }
-                    }
-                }
+                new Option<string>("--fruit").AddSuggestions("apple", "banana", "cherry"),
+                new Option<string>("--vegetable").AddSuggestions("asparagus", "broccoli", "carrot")
             };
 
             _testParser = new CommandLineBuilder(eatCommand)
diff --git a/src/System.CommandLine.Benchmarks/CommandLine/Perf_Parser_Options_Bare.cs b/src/System.CommandLine.Benchmarks/CommandLine/Perf_Parser_Options_Bare.cs
index 926b86cfe..5ed969570 100644
--- a/src/System.CommandLine.Benchmarks/CommandLine/Perf_Parser_Options_Bare.cs
+++ b/src/System.CommandLine.Benchmarks/CommandLine/Perf_Parser_Options_Bare.cs
@@ -21,13 +21,9 @@ public class Perf_Parser_Options_Bare
         private IEnumerable<Option> GenerateTestOptions(int count, IArgumentArity arity)
             => Enumerable.Range(0, count)
                          .Select(i =>
-                                     new Option($"-option{i}")
+                                     new Option($"-option{i}", arity: arity)
                                      {
-                                         Description = $"Description for -option {i} ....",
-                                         Argument = new Argument
-                                         {
-                                             Arity = arity
-                                         }
+                                         Description = $"Description for -option {i} ...."
                                      }
                          );
 
diff --git a/src/System.CommandLine.Benchmarks/CommandLine/Perf_Parser_Options_With_Arguments.cs b/src/System.CommandLine.Benchmarks/CommandLine/Perf_Parser_Options_With_Arguments.cs
index 9cd563c1a..2ff7ffd80 100644
--- a/src/System.CommandLine.Benchmarks/CommandLine/Perf_Parser_Options_With_Arguments.cs
+++ b/src/System.CommandLine.Benchmarks/CommandLine/Perf_Parser_Options_With_Arguments.cs
@@ -19,13 +19,9 @@ public class Perf_Parser_Options_With_Arguments
 
         private IEnumerable<Option> GenerateTestOptions(int count, IArgumentArity arity)
             => Enumerable.Range(0, count)
-                         .Select(i => new Option($"-option{i}")
+                         .Select(i => new Option($"-option{i}", arity: arity)
                              {
-                                 Description = $"Description for -option {i} ....",
-                                 Argument = new Argument
-                                 {
-                                     Arity = arity
-                                 }
+                                 Description = $"Description for -option {i} ...."
                              }
                          );
 
diff --git a/src/System.CommandLine.Benchmarks/CommandLine/Perf_Suggestions.cs b/src/System.CommandLine.Benchmarks/CommandLine/Perf_Suggestions.cs
index 0b0867209..ea483ddd5 100644
--- a/src/System.CommandLine.Benchmarks/CommandLine/Perf_Suggestions.cs
+++ b/src/System.CommandLine.Benchmarks/CommandLine/Perf_Suggestions.cs
@@ -37,14 +37,8 @@ private IEnumerable<Option> GenerateOptionsArray(int count)
         [GlobalSetup(Target = nameof(SuggestionsFromSymbol))]
         public void Setup_FromSymbol()
         {
-            _testSymbol = new Option("--hello")
-            {
-                Argument = new Argument
-                    {
-                        Arity = ArgumentArity.ExactlyOne,
-                        Suggestions = { GenerateSuggestionsArray(TestSuggestionsCount) }
-                }
-            };
+            _testSymbol = new Option("--hello", arity: ArgumentArity.ExactlyOne)
+                .AddSuggestions(GenerateSuggestionsArray(TestSuggestionsCount));
         }
 
         [Benchmark]
diff --git a/src/System.CommandLine.DragonFruit.Tests/ConfigureFromMethodTests.cs b/src/System.CommandLine.DragonFruit.Tests/ConfigureFromMethodTests.cs
index 2b6ab2dff..423e3d434 100644
--- a/src/System.CommandLine.DragonFruit.Tests/ConfigureFromMethodTests.cs
+++ b/src/System.CommandLine.DragonFruit.Tests/ConfigureFromMethodTests.cs
@@ -220,7 +220,7 @@ public void Options_are_not_built_for_infrastructure_types_exposed_by_method_par
             var options = handlerMethod.BuildOptions();
 
             options.Should()
-                   .NotContain(o => o.Argument.ArgumentType == type);
+                   .NotContain(o => o.ArgumentType == type);
         }
 
         [Fact]
diff --git a/src/System.CommandLine.DragonFruit/CommandLine.cs b/src/System.CommandLine.DragonFruit/CommandLine.cs
index 8c498a753..7a002feaf 100644
--- a/src/System.CommandLine.DragonFruit/CommandLine.cs
+++ b/src/System.CommandLine.DragonFruit/CommandLine.cs
@@ -290,24 +290,16 @@ public static IEnumerable<Option> BuildOptions(this MethodInfo method)
 
         public static Option BuildOption(this ParameterDescriptor parameter)
         {
-            var argument = new Argument
-                           {
-                               ArgumentType = parameter.ValueType
-                           };
-
+            Func<object> getDefaultValue = null;
             if (parameter.HasDefaultValue)
             {
-                argument.SetDefaultValueFactory(parameter.GetDefaultValue);
+                getDefaultValue = parameter.GetDefaultValue;
             }
-
-            var option = new Option(
+            return new Option(
                 parameter.BuildAlias(),
-                parameter.ValueName)
-            {
-                Argument = argument
-            };
-
-            return option;
+                parameter.ValueName,
+                parameter.ValueType,
+                getDefaultValue);
         }
 
         private static string GetDefaultXmlDocsFileLocation(Assembly assembly)
diff --git a/src/System.CommandLine.Hosting.Tests/HostingTests.cs b/src/System.CommandLine.Hosting.Tests/HostingTests.cs
index 73f9c9c1c..3243e47f0 100644
--- a/src/System.CommandLine.Hosting.Tests/HostingTests.cs
+++ b/src/System.CommandLine.Hosting.Tests/HostingTests.cs
@@ -201,10 +201,7 @@ public static void UseHost_binds_parsed_arguments_to_options()
             MyOptions options = null;
 
             var rootCmd = new RootCommand();
-            rootCmd.AddOption(
-                new Option($"-{nameof(MyOptions.MyArgument)}")
-                { Argument = new Argument<int>() }
-                );
+            rootCmd.AddOption(new Option<int>($"-{nameof(MyOptions.MyArgument)}"));
             rootCmd.Handler = CommandHandler.Create((IHost host) =>
             {
                 options = host.Services
diff --git a/src/System.CommandLine.Suggest.Tests/EndToEndTestApp/Program.cs b/src/System.CommandLine.Suggest.Tests/EndToEndTestApp/Program.cs
index 79b5fd37c..2619f82d1 100644
--- a/src/System.CommandLine.Suggest.Tests/EndToEndTestApp/Program.cs
+++ b/src/System.CommandLine.Suggest.Tests/EndToEndTestApp/Program.cs
@@ -13,22 +13,10 @@ static async Task Main(string[] args)
         {
             var rootCommand = new RootCommand
             {
-                new Option("--apple" )
-                {
-                    Argument = new Argument<string>()
-                },
-                new Option("--banana")
-                {
-                    Argument = new Argument<string>()
-                },
-                new Option("--cherry")
-                {
-                    Argument = new Argument<string>()
-                },
-                new Option("--durian")
-                {
-                    Argument = new Argument<string>()
-                }
+                new Option<string>("--apple" ),
+                new Option<string>("--banana"),
+                new Option<string>("--cherry"),
+                new Option<string>("--durian")
             };
 
             rootCommand.Handler = CommandHandler.Create(typeof(Program).GetMethod(nameof(Run)));
diff --git a/src/System.CommandLine.Tests/ArgumentTests.cs b/src/System.CommandLine.Tests/ArgumentTests.cs
index e8441c87c..e5f92e6cf 100644
--- a/src/System.CommandLine.Tests/ArgumentTests.cs
+++ b/src/System.CommandLine.Tests/ArgumentTests.cs
@@ -367,14 +367,11 @@ public async Task Custom_argument_parser_is_only_called_once()
                 {
                     Handler = CommandHandler.Create<int>(Run)
                 };
-                command.AddOption(new Option("--value")
+                command.AddOption(new Option<int>("--value", result =>
                 {
-                    Argument = new Argument<int>(result =>
-                    {
-                        callCount++;
-                        return int.Parse(result.Tokens.Single().Value);
-                    })
-                });
+                    callCount++;
+                    return int.Parse(result.Tokens.Single().Value);
+                }));
 
                 await command.InvokeAsync("--value 42");
 
@@ -439,14 +436,11 @@ public void When_custom_conversion_fails_then_an_option_does_not_accept_further_
                 var command = new Command("the-command")
                 {
                     new Argument<string>(),
-                    new Option("-x")
-                    {
-                        Argument = new Argument<string>(argResult =>
+                    new Option<string>("-x", argResult =>
                         {
                             argResult.ErrorMessage = "nope";
                             return default;
                         })
-                    }
                 };
 
                 var result = command.Parse("the-command -x nope yep");
@@ -459,9 +453,7 @@ public void When_argument_cannot_be_parsed_as_the_specified_type_then_getting_va
             {
                 var command = new Command("the-command")
                 {
-                    new Option(new[] { "-o", "--one" })
-                    {
-                        Argument = new Argument<int>(argumentResult =>
+                    new Option<int>(new[] { "-o", "--one" }, argumentResult =>
                         {
                             if (int.TryParse(argumentResult.Tokens.Select(t => t.Value).Single(), out var value))
                             {
@@ -472,7 +464,6 @@ public void When_argument_cannot_be_parsed_as_the_specified_type_then_getting_va
 
                             return default;
                         })
-                    }
                 };
 
                 var result = command.Parse("the-command -o not-an-int");
diff --git a/src/System.CommandLine.Tests/Binding/ModelBinderTests.cs b/src/System.CommandLine.Tests/Binding/ModelBinderTests.cs
index c7e5feedf..bccc5c9b3 100644
--- a/src/System.CommandLine.Tests/Binding/ModelBinderTests.cs
+++ b/src/System.CommandLine.Tests/Binding/ModelBinderTests.cs
@@ -29,13 +29,7 @@ public class ModelBinderTests
 
             var command = new Command("the-command")
                           {
-                              new Option("--value")
-                              {
-                                  Argument = new Argument
-                                             {
-                                                 ArgumentType = type
-                                             }
-                              }
+                              new Option("--value", argumentType: type)
                           };
 
             var bindingContext = new BindingContext(command.Parse(commandLine));
@@ -111,10 +105,7 @@ public class ModelBinderTests
         [Fact]
         public void Explicitly_configured_default_values_can_be_bound_by_name_to_constructor_parameters()
         {
-            var option = new Option("--string-option")
-            {
-                Argument = new Argument<string>(() => "the default")
-            };
+            var option = new Option<string>("--string-option", () => "the default");
 
             var command = new Command("the-command");
             command.AddOption(option);
@@ -143,13 +134,7 @@ public void Explicitly_configured_default_values_can_be_bound_by_name_to_constru
 
             var command = new Command("the-command")
                           {
-                              new Option("--value")
-                              {
-                                  Argument = new Argument
-                                             {
-                                                 ArgumentType = type
-                                             }
-                              }
+                              new Option("--value", argumentType: type)
                           };
             var parser = new Parser(command);
 
@@ -199,10 +184,7 @@ public void Types_having_constructors_accepting_a_single_string_are_bound_using_
         {
             var tempPath = Path.GetTempPath();
 
-            var option = new Option("--value")
-            {
-                Argument = new Argument<DirectoryInfo>()
-            };
+            var option = new Option<DirectoryInfo>("--value");
 
             var command = new Command("the-command");
             command.AddOption(option);
@@ -217,12 +199,7 @@ public void Types_having_constructors_accepting_a_single_string_are_bound_using_
         [Fact]
         public void Explicitly_configured_default_values_can_be_bound_by_name_to_property_setters()
         {
-            var argument = new Argument<string>(() => "the default");
-
-            var option = new Option("--value")
-            {
-                Argument = argument
-            };
+            var option = new Option<string>("--value", () => "the default");
 
             var command = new Command("the-command");
             command.AddOption(option);
@@ -241,10 +218,7 @@ public void Property_setters_with_no_default_value_and_no_matching_option_are_no
         {
             var command = new Command("the-command")
                           {
-                              new Option("--string-option")
-                              {
-                                  Argument = new Argument<string>()
-                              }
+                              new Option<string>("--string-option")
                           };
 
             var binder = new ModelBinder(typeof(ClassWithSettersAndCtorParametersWithDifferentNames));
@@ -263,10 +237,7 @@ public void Parse_result_can_be_used_to_create_an_instance_without_doing_handler
         {
             var parser = new Parser(new Command("the-command")
                                     {
-                                        new Option("--int-option")
-                                        {
-                                            Argument = new Argument<int>()
-                                        }
+                                        new Option<int>("--int-option")
                                     });
             var bindingContext = new BindingContext(parser.Parse("the-command --int-option 123"));
             var binder = new ModelBinder(typeof(ClassWithMultiLetterSetters));
@@ -281,10 +252,7 @@ public void Parse_result_can_be_used_to_modify_an_existing_instance_without_doin
         {
             var parser = new Parser(new Command("the-command")
                                     {
-                                        new Option("--int-option")
-                                        {
-                                            Argument = new Argument<int>()
-                                        }
+                                        new Option<int>("--int-option")
                                     });
             var instance = new ClassWithMultiLetterSetters();
             var bindingContext = new BindingContext(parser.Parse("the-command --int-option 123"));
@@ -300,10 +268,7 @@ public void Values_from_options_on_parent_commands_are_bound_by_name_by_default(
         {
             var parentCommand = new Command("parent-command")
                                 {
-                                    new Option("--int-option")
-                                    {
-                                        Argument = new Argument<int>()
-                                    },
+                                    new Option<int>("--int-option"),
                                     new Command("child-command")
                                 };
 
@@ -323,10 +288,7 @@ public void Default_values_from_options_on_parent_commands_are_bound_by_name_by_
         {
             var parentCommand = new Command("parent-command")
                                 {
-                                    new Option("--int-option")
-                                    {
-                                        Argument = new Argument<int>(() => 123)
-                                    },
+                                    new Option<int>("--int-option", () => 123),
                                     new Command("child-command")
                                 };
 
@@ -391,10 +353,7 @@ public void Default_values_from_parent_command_arguments_are_bound_by_name_by_de
         public void Values_from_options_on_parent_commands_can_be_bound_regardless_of_naming()
         {
             var childCommand = new Command("child-command");
-            var option = new Option("-x")
-            {
-                Argument = new Argument<int>()
-            };
+            var option = new Option<int>("-x");
             var parentCommand = new Command("parent-command")
                                 {
                                     option,
@@ -436,10 +395,7 @@ public void Arbitrary_values_can_be_bound()
         public void PropertyInfo_can_be_bound_to_option()
         {
             var command = new Command("the-command");
-            var option = new Option("--fred")
-            {
-                Argument = new Argument<int>()
-            };
+            var option = new Option<int>("--fred");
             command.Add(option);
 
             var type = typeof(ClassWithMultiLetterSetters);
@@ -481,7 +437,7 @@ public void PropertyInfo_can_be_bound_to_argument()
         public void PropertyExpression_can_be_bound_to_option()
         {
             var command = new Command("the-command");
-            var option = new Option("--fred") { Argument = new Argument<int>() };
+            var option = new Option<int>("--fred");
             command.AddOption(option);
 
             var binder = new ModelBinder<ClassWithMultiLetterSetters>();
@@ -520,7 +476,7 @@ public void PropertyExpression_can_be_bound_to_argument()
         [Fact]
         public void Option_argument_is_bound_to_longest_constructor()
         {
-            var option = new Option("--int-property") { Argument = new Argument<int>() };
+            var option = new Option<int>("--int-property");
             var parser = new Parser(option);
 
             var bindingContext = new BindingContext(parser.Parse("--int-property 42"));
@@ -549,8 +505,8 @@ public void Command_argument_is_bound_to_longest_constructor()
         [Fact]
         public void Explicit_model_binder_binds_only_to_configured_properties()
         {
-            var intOption = new Option("--int-property") { Argument = new Argument<int>() };
-            var stringOption = new Option("--string-property") { Argument = new Argument<string>() };
+            var intOption = new Option<int>("--int-property");
+            var stringOption = new Option<string>("--string-property");
             var parser = new Parser(intOption, stringOption);
 
             var bindingContext = new BindingContext(parser.Parse("--int-property 42 --string-property Hello"));
@@ -569,8 +525,8 @@ public void Explicit_model_binder_binds_only_to_configured_properties()
         [Fact]
         public void Explicit_model_binder_binds_only_to_configured_ctor_parameters()
         {
-            var intOption = new Option("-a") { Argument = new Argument<int>() };
-            var stringOption = new Option("-b") { Argument = new Argument<string>() };
+            var intOption = new Option<int>("-a");
+            var stringOption = new Option<string>("-b");
             var parser = new Parser(intOption, stringOption);
             var ctor = typeof(ClassWithMultiLetterCtorParameters)
                 .GetConstructors(BindingFlags.Public | BindingFlags.Instance)[0];
diff --git a/src/System.CommandLine.Tests/Binding/ModelBindingCommandHandlerTests.cs b/src/System.CommandLine.Tests/Binding/ModelBindingCommandHandlerTests.cs
index f6fbc005c..6a422a324 100644
--- a/src/System.CommandLine.Tests/Binding/ModelBindingCommandHandlerTests.cs
+++ b/src/System.CommandLine.Tests/Binding/ModelBindingCommandHandlerTests.cs
@@ -36,13 +36,9 @@ public class ModelBindingCommandHandlerTests
 
             var command = new Command("the-command")
                           {
-                              new Option("--value")
+                              new Option("--value", argumentType: type)
                               {
-                                  Argument = new Argument
-                                             {
-                                                 Name = "value",
-                                                 ArgumentType = type
-                                             }
+                                  ArgumentName = "value"
                               }
                           };
 
@@ -75,13 +71,9 @@ public class ModelBindingCommandHandlerTests
 
             var command = new Command("the-command")
                           {
-                              new Option("--value")
+                              new Option("--value", argumentType: type)
                               {
-                                  Argument = new Argument
-                                             {
-                                                 Name = "value",
-                                                 ArgumentType = type
-                                             }
+                                  ArgumentName = "value"
                               }
                           };
 
@@ -114,13 +106,9 @@ public class ModelBindingCommandHandlerTests
 
             var command = new Command("the-command")
                           {
-                              new Option("--value")
+                              new Option("--value", argumentType: type)
                               {
-                                  Argument = new Argument
-                                             {
-                                                 Name = "value",
-                                                 ArgumentType = type
-                                             }
+                                  ArgumentName = "value"
                               }
                           };
 
@@ -137,10 +125,9 @@ public void When_name_is_not_among_aliases_then_binder_will_bind_option_by_name(
         {
             var rootCommand = new RootCommand
             {
-                new Option("-n")
+                new Option<string[]>("-n")
                 {
-                    Argument = new Argument<string[]>("header"),
-                    Name = "name"
+                    ArgumentName = "name"
                 }
             };
 
@@ -202,13 +189,9 @@ public void When_name_is_not_among_aliases_then_binder_will_bind_option_by_name(
 
             var command = new Command("command")
                           {
-                              new Option("-x")
+                              new Option("-x", argumentType: parameterType)
                               {
-                                  Argument = new Argument
-                                  {
-                                      Name = "value",
-                                      ArgumentType = parameterType
-                                  }
+                                  ArgumentName = "value"
                               }
                           };
 
@@ -252,13 +235,7 @@ public async Task When_argument_type_is_not_known_until_binding_then_int_paramet
 
             var root = new RootCommand
             {
-                new Option("-x")
-                {
-                    Argument = new Argument
-                    {
-                        Arity = new ArgumentArity(1, 1)
-                    }
-                }
+                new Option("-x", arity: new ArgumentArity(1, 1))
             };
             root.Handler = handler;
 
@@ -352,13 +329,7 @@ public void When_argument_type_is_more_specific_than_parameter_type_then_paramet
 
             var command = new Command("command")
                           {
-                              new Option("--value")
-                              {
-                                  Argument = new Argument
-                                             {
-                                                 ArgumentType = testCase.ParameterType
-                                             }
-                              }
+                              new Option("--value", argumentType: testCase.ParameterType)
                           };
             command.Handler = handler;
 
@@ -380,12 +351,9 @@ public async Task When_binding_fails_due_to_parameter_naming_mismatch_then_handl
         {
             string[] received = { "this should get overwritten" };
 
-            var o = new Option(
+            var o = new Option<string[]>(
                 new[] { "-i" },
-                "Path to an image or directory of supported images")
-            {
-                Argument = new Argument<string[]>()
-            };
+                "Path to an image or directory of supported images");
 
             var command = new Command("command") { o };
             command.Handler = CommandHandler.Create<string[], InvocationContext>((nameDoesNotMatch, c) => received = nameDoesNotMatch);
@@ -528,16 +496,9 @@ public async Task When_binding_fails_due_to_parameter_naming_mismatch_then_handl
 
             var handler = CommandHandler.Create(captureMethod);
 
-            var option = new Option("--value")
-            {
-                Argument = new Argument
-                {
-                    ArgumentType = c.ParameterType
-                }
-            };
+            var option = new Option("--value", argumentType: c.ParameterType);
 
-            var command = new Command(
-                "command")
+            var command = new Command("command")
             {
                 option
             };
@@ -545,7 +506,7 @@ public async Task When_binding_fails_due_to_parameter_naming_mismatch_then_handl
             {
                 throw new InvalidOperationException("Cannot bind to this type of handler");
             }
-            bindingHandler.BindParameter(parameter, option); 
+            bindingHandler.BindParameter(parameter, option);
             command.Handler = handler;
 
             var commandLine = $"--value {c.CommandLine}";
diff --git a/src/System.CommandLine.Tests/Binding/TypeConversionTests.cs b/src/System.CommandLine.Tests/Binding/TypeConversionTests.cs
index 42f4456d5..9e649ec04 100644
--- a/src/System.CommandLine.Tests/Binding/TypeConversionTests.cs
+++ b/src/System.CommandLine.Tests/Binding/TypeConversionTests.cs
@@ -106,17 +106,6 @@ public void Command_Argument_defaults_arity_to_ZeroOrOne_for_nullable_types()
             command.Arguments.Single().Arity.Should().BeEquivalentTo(ArgumentArity.ZeroOrOne);
         }
 
-        [Fact]
-        public void Option_Argument_defaults_arity_to_ExactlyOne_for_nullable_types()
-        {
-            var option = new Option("-i")
-            {
-                Argument = new Argument<int?>()
-            };
-
-            option.Argument.Arity.Should().BeEquivalentTo(ArgumentArity.ExactlyOne);
-        }
-
         [Theory]
         [InlineData(typeof(int[]))]
         [InlineData(typeof(IEnumerable<int>))]
@@ -196,13 +185,7 @@ public void By_default_an_option_with_zero_or_one_argument_parses_as_the_argumen
         {
             var command = new Command("the-command")
             {
-                new Option("-x")
-                {
-                    Argument = new Argument
-                    {
-                        Arity = ArgumentArity.ZeroOrOne
-                    }
-                }
+                new Option("-x", arity: ArgumentArity.ZeroOrOne)
             };
 
             var result = command.Parse("the-command -x the-argument");
@@ -217,13 +200,7 @@ public void By_default_an_option_with_exactly_one_argument_parses_as_the_argumen
         {
             var command = new Command("the-command")
             {
-                new Option("-x")
-                {
-                    Argument = new Argument
-                    {
-                        Arity = ArgumentArity.ExactlyOne
-                    }
-                }
+                new Option("-x", arity: ArgumentArity.ExactlyOne)
             };
 
             var result = command.Parse("the-command -x the-argument");
@@ -238,13 +215,7 @@ public void When_exactly_one_argument_is_expected_and_none_are_provided_then_get
         {
             var command = new Command("the-command")
             {
-                new Option("-x")
-                {
-                    Argument = new Argument
-                    {
-                        Arity = ArgumentArity.ExactlyOne
-                    }
-                }
+                new Option("-x", arity: ArgumentArity.ExactlyOne)
             };
 
             var result = command.Parse("the-command -x");
@@ -264,13 +235,7 @@ public void When_zero_or_more_arguments_of_unspecified_type_are_expected_and_non
         {
             var command = new Command("the-command")
             {
-                new Option("-x")
-                {
-                    Argument = new Argument
-                    {
-                        Arity = ArgumentArity.ZeroOrMore
-                    }
-                }
+                new Option("-x", arity: ArgumentArity.ZeroOrMore)
             };
 
             var result = command.Parse("the-command -x");
@@ -287,15 +252,7 @@ public void When_zero_or_more_arguments_of_unspecified_type_are_expected_and_non
         public void
             When_zero_or_more_arguments_of_unspecified_type_are_expected_and_none_are_provided_and_there_is_a_default_then_getting_value_returns_default_in_an_empty_sequence_of_strings()
         {
-            var option = new Option("-x")
-            {
-                Argument = new Argument
-                {
-                    Arity = ArgumentArity.ZeroOrMore
-                }
-            };
-
-            option.Argument.SetDefaultValueFactory(() => "the-default");
+            var option = new Option("-x", getDefaultValue: () => "the-default", arity: ArgumentArity.ZeroOrMore);
 
             var command = new Command("the-command")
             {
@@ -317,13 +274,7 @@ public void When_one_or_more_arguments_of_unspecified_type_are_expected_and_none
         {
             var command = new Command("the-command")
             {
-                new Option("-x")
-                {
-                    Argument = new Argument
-                    {
-                        Arity = ArgumentArity.OneOrMore
-                    }
-                }
+                new Option("-x", arity: ArgumentArity.OneOrMore)
             };
 
             var result = command.Parse("the-command -x");
@@ -343,13 +294,7 @@ public void By_default_an_option_that_allows_multiple_arguments_and_is_passed_mu
         {
             var command = new Command("the-command")
             {
-                new Option("-x")
-                {
-                    Argument = new Argument
-                    {
-                        Arity = ArgumentArity.ZeroOrMore
-                    }
-                }
+                new Option("-x", arity: ArgumentArity.ZeroOrMore)
             };
 
             command.Parse("the-command -x arg1 -x arg2")
@@ -363,13 +308,7 @@ public void By_default_an_option_that_allows_multiple_arguments_and_is_passed_on
         {
             var command = new Command("the-command")
             {
-                new Option("-x")
-                {
-                    Argument = new Argument
-                    {
-                        Arity = ArgumentArity.ZeroOrMore
-                    }
-                }
+                new Option("-x", arity: ArgumentArity.ZeroOrMore)
             };
 
             command.Parse("the-command -x arg1")
@@ -386,17 +325,13 @@ public void When_command_argument_has_arity_greater_than_one_it_captures_argumen
         {
             var command = new Command("the-command")
             {
-                new Option("-a")
-                {
-                    Argument = new Argument<string>()
-                },
+                new Option<string>("-a"),
                 new Argument<string>("the-arg")
                 {
                     Arity = ArgumentArity.ZeroOrMore
                 }
             };
 
-
             var result = command.Parse(commandLine);
 
             result.ValueForArgument("the-arg")
@@ -512,10 +447,7 @@ public void A_default_value_with_a_custom_constructor_can_be_specified_for_a_com
         [Fact]
         public void An_option_argument_with_a_default_argument_can_be_converted_to_the_requested_type()
         {
-            var option = new Option("-x")
-            {
-                Argument = new Argument<string>(() => "123")
-            };
+            var option = new Option<string>("-x", () => "123");
 
             var command = new Command("something")
             {
@@ -534,10 +466,7 @@ public void Specifying_an_option_argument_overrides_the_default_value()
         {
             var command = new Command("something")
             {
-                new Option("-x")
-                {
-                    Argument = new Argument<int>(() => 123)
-                }
+                new Option<int>("-x", () => 123)
             };
 
             var result = command.Parse("something -x 456");
@@ -550,13 +479,7 @@ public void Specifying_an_option_argument_overrides_the_default_value()
         [Fact]
         public void Values_can_be_correctly_converted_to_int_without_the_parser_specifying_a_custom_converter()
         {
-            var option = new Option("-x")
-            {
-                Argument = new Argument
-                {
-                    Arity = ArgumentArity.ZeroOrOne
-                }
-            };
+            var option = new Option("-x", arity: ArgumentArity.ZeroOrOne);
 
             var value = option.Parse("-x 123").ValueForOption<int>(option);
 
@@ -566,13 +489,7 @@ public void Values_can_be_correctly_converted_to_int_without_the_parser_specifyi
         [Fact]
         public void Values_can_be_correctly_converted_to_nullable_int_with_no_value_without_the_parser_specifying_a_custom_converter()
         {
-            var option = new Option("-x")
-            {
-                Argument = new Argument
-                {
-                    Arity = ArgumentArity.ZeroOrOne
-                }
-            };
+            var option = new Option("-x", arity: ArgumentArity.ZeroOrOne);
 
             var value = option.Parse("").ValueForOption<int?>("-x");
 
@@ -582,13 +499,7 @@ public void Values_can_be_correctly_converted_to_nullable_int_with_no_value_with
         [Fact]
         public void Values_can_be_correctly_converted_to_nullable_int_with_a_value_without_the_parser_specifying_a_custom_converter()
         {
-            var option = new Option("-x")
-            {
-                Argument = new Argument
-                {
-                    Arity = ArgumentArity.ZeroOrOne
-                }
-            };
+            var option = new Option("-x", arity: ArgumentArity.ZeroOrOne);
 
             var value = option.Parse("-x 123").ValueForOption<int?>(option);
 
@@ -598,13 +509,7 @@ public void Values_can_be_correctly_converted_to_nullable_int_with_a_value_witho
         [Fact]
         public void Values_can_be_correctly_converted_to_decimal_without_the_parser_specifying_a_custom_converter()
         {
-            var option = new Option("-x")
-            {
-                Argument = new Argument
-                {
-                    Arity = ArgumentArity.ZeroOrOne
-                }
-            };
+            var option = new Option("-x", arity: ArgumentArity.ZeroOrOne);
 
             var value = option.Parse("-x 123.456").ValueForOption<decimal>(option);
 
@@ -614,13 +519,7 @@ public void Values_can_be_correctly_converted_to_decimal_without_the_parser_spec
         [Fact]
         public void Values_can_be_correctly_converted_to_double_without_the_parser_specifying_a_custom_converter()
         {
-            var option = new Option("-x")
-            {
-                Argument = new Argument
-                {
-                    Arity = ArgumentArity.ZeroOrOne
-                }
-            };
+            var option = new Option("-x", arity: ArgumentArity.ZeroOrOne);
 
             var value = option.Parse("-x 123.456").ValueForOption<double>("-x");
 
@@ -630,13 +529,7 @@ public void Values_can_be_correctly_converted_to_double_without_the_parser_speci
         [Fact]
         public void Values_can_be_correctly_converted_to_float_without_the_parser_specifying_a_custom_converter()
         {
-            var option = new Option("-x")
-            {
-                Argument = new Argument
-                {
-                    Arity = ArgumentArity.ZeroOrOne
-                }
-            };
+            var option = new Option("-x", arity: ArgumentArity.ZeroOrOne);
 
             var value = option.Parse("-x 123.456").ValueForOption<float>("-x");
 
@@ -646,13 +539,7 @@ public void Values_can_be_correctly_converted_to_float_without_the_parser_specif
         [Fact]
         public void Options_with_no_arguments_specified_can_be_correctly_converted_to_bool_without_the_parser_specifying_it()
         {
-            var option = new Option("-x")
-            {
-                Argument = new Argument
-                {
-                    Arity = ArgumentArity.ZeroOrOne
-                }
-            };
+            var option = new Option("-x", arity: ArgumentArity.ZeroOrOne);
 
             option.Parse("-x").ValueForOption<bool>("-x").Should().BeTrue();
         }
@@ -660,13 +547,7 @@ public void Options_with_no_arguments_specified_can_be_correctly_converted_to_bo
         [Fact]
         public void Options_with_arguments_specified_can_be_correctly_converted_to_bool_without_the_parser_specifying_a_custom_converter()
         {
-            var option = new Option("-x")
-            {
-                Argument = new Argument
-                {
-                    Arity = ArgumentArity.ZeroOrOne
-                }
-            };
+            var option = new Option("-x", arity: ArgumentArity.ZeroOrOne);
 
             option.Parse("-x false").ValueForOption<bool>("-x").Should().BeFalse();
             option.Parse("-x true").ValueForOption<bool>("-x").Should().BeTrue();
@@ -675,13 +556,7 @@ public void Options_with_arguments_specified_can_be_correctly_converted_to_bool_
         [Fact]
         public void Values_can_be_correctly_converted_to_array_of_int_without_the_parser_specifying_a_custom_converter()
         {
-            var option = new Option("-x")
-            {
-                Argument = new Argument
-                {
-                    Arity = ArgumentArity.ZeroOrMore
-                }
-            };
+            var option = new Option("-x", arity: ArgumentArity.ZeroOrMore);
 
             var value = option.Parse("-x 1 -x 2 -x 3").ValueForOption<int[]>("-x");
 
@@ -715,16 +590,7 @@ public void Values_can_be_correctly_converted_to_array_of_int_without_the_parser
             int maxArity,
             Type argumentType)
         {
-            var argument = new Argument
-            {
-                ArgumentType = argumentType,
-                Arity = new ArgumentArity(minArity, maxArity)
-            };
-
-            var option = new Option("--items")
-            {
-                Argument = argument
-            };
+            var option = new Option("--items", argumentType: argumentType, arity: new ArgumentArity(minArity, maxArity));
 
             var command = new RootCommand
             {
@@ -740,13 +606,7 @@ public void Values_can_be_correctly_converted_to_array_of_int_without_the_parser
         [Fact]
         public void Values_can_be_correctly_converted_to_List_of_int_without_the_parser_specifying_a_custom_converter()
         {
-            var option = new Option("-x")
-            {
-                Argument = new Argument
-                {
-                    Arity = ArgumentArity.ZeroOrMore
-                }
-            };
+            var option = new Option("-x", arity: ArgumentArity.ZeroOrMore);
 
             var value = option.Parse("-x 1 -x 2 -x 3").ValueForOption<List<int>>("-x");
 
@@ -756,13 +616,7 @@ public void Values_can_be_correctly_converted_to_List_of_int_without_the_parser_
         [Fact]
         public void Values_can_be_correctly_converted_to_IEnumerable_of_int_without_the_parser_specifying_a_custom_converter()
         {
-            var option = new Option("-x")
-            {
-                Argument = new Argument
-                {
-                    Arity = ArgumentArity.ZeroOrMore
-                }
-            };
+            var option = new Option("-x", arity: ArgumentArity.ZeroOrMore);
 
             var value = option.Parse("-x 1 -x 2 -x 3").ValueForOption<IEnumerable<int>>("-x");
 
@@ -772,10 +626,7 @@ public void Values_can_be_correctly_converted_to_IEnumerable_of_int_without_the_
         [Fact]
         public void Enum_values_can_be_correctly_converted_based_on_enum_value_name_without_the_parser_specifying_a_custom_converter()
         {
-            var option = new Option("-x")
-            {
-                Argument = new Argument<DayOfWeek>()
-            };
+            var option = new Option<DayOfWeek>("-x");
 
             var parseResult = option.Parse("-x Monday");
 
@@ -787,10 +638,7 @@ public void Enum_values_can_be_correctly_converted_based_on_enum_value_name_with
         [Fact]
         public void Enum_values_that_cannot_be_parsed_result_in_an_informative_error()
         {
-            var option = new Option("-x")
-            {
-                Argument = new Argument<DayOfWeek>()
-            };
+            var option = new Option<DayOfWeek>("-x");
 
             var value = option.Parse("-x Notaday");
 
@@ -803,13 +651,7 @@ public void Enum_values_that_cannot_be_parsed_result_in_an_informative_error()
         [Fact]
         public void When_getting_values_and_specifying_a_conversion_type_that_is_not_supported_then_it_throws()
         {
-            var option = new Option("-x")
-            {
-                Argument = new Argument
-                {
-                    Arity = ArgumentArity.ZeroOrOne
-                }
-            };
+            var option = new Option("-x", arity: ArgumentArity.ZeroOrOne);
 
             var result = option.Parse("-x not-an-int");
 
@@ -826,13 +668,7 @@ public void When_getting_values_and_specifying_a_conversion_type_that_is_not_sup
         [Fact]
         public void When_getting_an_array_of_values_and_specifying_a_conversion_type_that_is_not_supported_then_it_throws()
         {
-            var option = new Option("-x")
-            {
-                Argument = new Argument
-                {
-                    Arity = ArgumentArity.ZeroOrOne
-                }
-            };
+            var option = new Option("-x", arity: ArgumentArity.ZeroOrOne);
 
             var result = option.Parse("-x not-an-int -x 2");
 
diff --git a/src/System.CommandLine.Tests/CommandTests.cs b/src/System.CommandLine.Tests/CommandTests.cs
index 9fad14c16..fc763112f 100644
--- a/src/System.CommandLine.Tests/CommandTests.cs
+++ b/src/System.CommandLine.Tests/CommandTests.cs
@@ -19,13 +19,7 @@ public CommandTests()
                 {
                     new Command("inner")
                     {
-                        new Option("--option")
-                        {
-                            Argument = new Argument
-                            {
-                                Arity = ArgumentArity.ExactlyOne
-                            }
-                        }
+                        new Option("--option", arity: ArgumentArity.ExactlyOne)
                     }
                 });
         }
diff --git a/src/System.CommandLine.Tests/Help/HelpBuilderTests.Approval.cs b/src/System.CommandLine.Tests/Help/HelpBuilderTests.Approval.cs
index 63d7ce013..34bfed78d 100644
--- a/src/System.CommandLine.Tests/Help/HelpBuilderTests.Approval.cs
+++ b/src/System.CommandLine.Tests/Help/HelpBuilderTests.Approval.cs
@@ -40,34 +40,29 @@ public void Help_describes_default_values_for_complex_root_command_scenario()
                     parseArgument: _ => "the-root-option--no-description-default-arg-value",
                     isDefault: true
                 ),
-                new Option(aliases: new string[] {"--the-root-option-no-default-arg", "-tronda"}) {
+                new Option<string>(aliases: new string[] {"--the-root-option-no-default-arg", "-tronda"}) {
                     Description = "the-root-option-no-default-description",
-                    Argument = new Argument<string>("the-root-option-arg-no-default-arg")
-                    {
-                        Description = "the-root-option-arg-no-default-description"
-                    },
+                    ArgumentName = "the-root-option-arg-no-default-arg",
+                    ArgumentDescription = "the-root-option-arg-no-default-description",
                     IsRequired = true
                 },
-                new Option(aliases: new string[] {"--the-root-option-default-arg", "-troda"}) {
+                new Option<string>(aliases: new string[] {"--the-root-option-default-arg", "-troda"}, () => "the-root-option-arg-value") 
+                {
                     Description = "the-root-option-default-arg-description",
-                    Argument = new Argument<string>("the-root-option-arg", () => "the-root-option-arg-value")
-                    {
-                        Description = "the-root-option-arg-description"
-                    },
+                    ArgumentName = "the-root-option-arg",
+                    ArgumentDescription = "the-root-option-arg-description"
                 },
-                new Option(aliases: new string[] {"--the-root-option-enum-arg", "-troea"}) {
+                new Option<FileAccess>(aliases: new string[] {"--the-root-option-enum-arg", "-troea"}, () => FileAccess.Read) 
+                {
                     Description = "the-root-option-description",
-                    Argument = new Argument<FileAccess>("the-root-option-arg", () => FileAccess.Read)
-                    {
-                        Description = "the-root-option-arg-description",
-                    }
+                    ArgumentName = "the-root-option-arg",
+                    ArgumentDescription = "the-root-option-arg-description"
                 },
-                new Option(aliases: new string[] {"--the-root-option-required-enum-arg", "-trorea"}) {
+                new Option<FileAccess>(aliases: new string[] {"--the-root-option-required-enum-arg", "-trorea"}, () => FileAccess.Read) 
+                {
                     Description = "the-root-option-description",
-                    Argument = new Argument<FileAccess>("the-root-option-arg", () => FileAccess.Read)
-                    {
-                        Description = "the-root-option-arg-description",
-                    },
+                    ArgumentName = "the-root-option-arg",
+                    ArgumentDescription = "the-root-option-arg-description",
                     IsRequired = true
                 },
                 new Option(aliases: new string[] {"--the-root-option-multi-line-description", "-tromld"}) {
diff --git a/src/System.CommandLine.Tests/Help/HelpBuilderTests.cs b/src/System.CommandLine.Tests/Help/HelpBuilderTests.cs
index 33d4a492b..521b0f944 100644
--- a/src/System.CommandLine.Tests/Help/HelpBuilderTests.cs
+++ b/src/System.CommandLine.Tests/Help/HelpBuilderTests.cs
@@ -512,12 +512,9 @@ public void Arguments_section_is_not_included_if_there_are_only_options_with_arg
         {
             var command = new Command("command")
             {
-                new Option("-v", "Sets the verbosity.")
+                new Option("-v", "Sets the verbosity.", arity: ArgumentArity.ExactlyOne)
                 {
-                    Argument = new Argument
-                    {
-                        Name = "argument for options", Arity = ArgumentArity.ExactlyOne
-                    }
+                    ArgumentName = "argument for options"
                 }
             };
 
@@ -531,12 +528,9 @@ public void Arguments_section_includes_configured_argument_aliases()
         {
             var command = new Command("the-command", "command help")
             {
-                new Option(new[] { "-v", "--verbosity" })
+                new Option(new[] { "-v", "--verbosity" }, arity: ArgumentArity.ExactlyOne)
                 {
-                    Argument = new Argument
-                    {
-                        Name = "LEVEL", Arity = ArgumentArity.ExactlyOne
-                    },
+                    ArgumentName = "LEVEL",
                     Description = "Sets the verbosity."
                 }
             };
@@ -870,14 +864,7 @@ public void Option_argument_descriptor_is_empty_for_boolean_values(Type type)
             var command = new Command(
                 "outer", "Help text for the outer command")
                           {
-                              new Option("--opt", description)
-                              {
-                                  Argument = new Argument
-                                             {
-                                                 Description = description,
-                                                 ArgumentType = type
-                                             }
-                              }
+                              new Option("--opt", description, argumentType: type)
                           };
 
             HelpBuilder helpBuilder = GetHelpBuilder(SmallMaxWidth);
@@ -897,13 +884,7 @@ public void Option_argument_descriptor_indicates_enums_values(Type type)
             var command = new Command(
                               "outer", "Help text for the outer command")
                           {
-                              new Option("--opt", description)
-                              {
-                                  Argument = new Argument
-                                             {
-                                                 ArgumentType = type
-                                             }
-                              }
+                              new Option("--opt", description, argumentType: type)
                           };
 
             HelpBuilder helpBuilder = GetHelpBuilder(SmallMaxWidth);
@@ -1184,21 +1165,15 @@ public void Options_section_properly_wraps()
         public void Options_section_does_not_contain_hidden_argument()
         {
             var command = new Command("the-command", "Does things.");
-            var opt1 = new Option("option1")
+            var opt1 = new Option<int>("option1")
             {
-                Argument = new Argument<int>
-                {
-                    Name = "the-hidden",
-                    IsHidden = true
-                }
+                ArgumentName = "the-hidden",
+                ArgumentIsHidden = true,
             };
-            var opt2 = new Option("option2")
+            var opt2 = new Option<int>("option2")
             {
-                Argument = new Argument<int>
-                {
-                    Name = "the-visible",
-                    IsHidden = false
-                }
+                ArgumentName = "the-visible",
+                ArgumentIsHidden = false
             };
             command.AddOption(opt1);
             command.AddOption(opt2);
@@ -1234,10 +1209,10 @@ public void Required_options_are_indicated_when_argument_is_named()
         {
             var command = new RootCommand
             {
-                new Option(new[] {"-r", "--required" })
+                new Option<string>(new[] {"-r", "--required" })
                 {
                     IsRequired = true,
-                    Argument = new Argument<string>("ARG")
+                    ArgumentName = "ARG"
                 }
             };
 
@@ -1337,17 +1312,11 @@ public void Option_aliases_are_shown_before_long_names_regardless_of_alphabetica
         [Fact]
         public void Help_describes_default_value_for_option_with_argument_having_default_value()
         {
-            var argument = new Argument
-            {
-                Name = "the-arg",
-            };
-            argument.SetDefaultValue("the-arg-value");
-
             var command = new Command("the-command", "command help")
             {
-                new Option(new[] { "-arg"})
+                new Option(new[] { "-arg"}, getDefaultValue: () => "the-arg-value")
                 {
-                    Argument = argument
+                    ArgumentName = "the-arg"
                 }
             };
 
@@ -1363,17 +1332,12 @@ public void Help_describes_default_value_for_option_with_argument_having_default
         [Fact]
         public void Help_should_not_contain_default_value_for_hidden_argument_defined_for_option()
         {
-            var argument = new Argument
-            {
-                Name = "the-arg",
-                IsHidden = true
-            };
-            argument.SetDefaultValue("the-arg-value");
             var command = new Command("the-command", "command help")
             {
-                new Option(new[] { "-arg"})
+                new Option(new[] { "-arg"}, getDefaultValue: () => "the-arg-value")
                 {
-                    Argument = argument
+                    ArgumentName = "the-arg",
+                    ArgumentIsHidden = true
                 }
             };
 
diff --git a/src/System.CommandLine.Tests/Invocation/CommandHandlerTests.cs b/src/System.CommandLine.Tests/Invocation/CommandHandlerTests.cs
index 33e83e2d7..00cb6e4c1 100644
--- a/src/System.CommandLine.Tests/Invocation/CommandHandlerTests.cs
+++ b/src/System.CommandLine.Tests/Invocation/CommandHandlerTests.cs
@@ -44,16 +44,8 @@ void Execute(string name, int age)
             }
 
             var command = new Command("command");
-            command.AddOption(
-                new Option("--name")
-                {
-                    Argument = new Argument<string>()
-                });
-            command.AddOption(
-                new Option("--age")
-                {
-                    Argument = new Argument<int>()
-                });
+            command.AddOption(new Option<string>("--name"));
+            command.AddOption(new Option<int>("--age"));
             command.Handler = CommandHandler.Create<string, int>(Execute);
 
             await command.InvokeAsync("command --age 425 --name Gandalf", _console);
@@ -75,16 +67,8 @@ void Execute(string n, int a)
             }
 
             var command = new Command("command");
-            command.AddOption(
-                new Option("--name")
-                {
-                    Argument = new Argument<string>()
-                });
-            command.AddOption(
-                new Option("--age")
-                {
-                    Argument = new Argument<int>()
-                });
+            command.AddOption(new Option<string>("--name"));
+            command.AddOption(new Option<string>("--age"));
             command.Handler = CommandHandler.Create<string, int>(Execute);
 
             await command.InvokeAsync("command --age 425 --name Gandalf", _console);
@@ -105,13 +89,7 @@ void Execute(string firstName)
 
             var command = new Command("command")
             {
-                new Option("--first-name")
-                {
-                    Argument = new Argument
-                    {
-                        Arity = ArgumentArity.ExactlyOne
-                    }
-                }
+                new Option("--first-name", arity: ArgumentArity.ExactlyOne)
             };
             command.Handler = CommandHandler.Create<string>(Execute);
 
@@ -133,14 +111,8 @@ void Execute(string name, int AGE)
             }
 
             var command = new Command("command");
-            command.AddOption(new Option("--NAME")
-            {
-                Argument = new Argument { Arity = ArgumentArity.ExactlyOne }
-            });
-            command.AddOption(new Option("--age")
-            {
-                Argument = new Argument<int>()
-            });
+            command.AddOption(new Option("--NAME", arity: ArgumentArity.ExactlyOne));
+            command.AddOption(new Option<int>("--age"));
             command.Handler = CommandHandler.Create<string, int>(Execute);
 
             await command.InvokeAsync("command --age 425 --NAME Gandalf", _console);
@@ -163,14 +135,8 @@ void Execute(string name, int age)
 
             var command = new Command("command")
             {
-                new Option("--name")
-                {
-                    Argument = new Argument<string>()
-                },
-                new Option("--age")
-                {
-                    Argument = new Argument<int>()
-                }
+                new Option<string>("--name"),
+                new Option<int>("--age")
             };
             command.Handler = CommandHandler.Create<string, int>(Execute);
 
@@ -194,14 +160,8 @@ void Execute(string name, int age)
 
             var command = new Command("command")
             {
-                new Option(new[] { "-n", "--NAME" })
-                {
-                    Argument = new Argument<string>()
-                },
-                new Option(new[] { "-a", "--age" })
-                {
-                    Argument = new Argument<int>()
-                }
+                new Option<string>(new[] { "-n", "--NAME" }),
+                new Option<int>(new[] { "-a", "--age" })
             };
             command.Handler = CommandHandler.Create<string, int>(Execute);
 
@@ -219,14 +179,8 @@ public async Task Method_parameters_on_the_invoked_lambda_are_bound_to_matching_
 
             var command = new Command("command")
             {
-                new Option("--name")
-                {
-                    Argument = new Argument<string>()
-                },
-                new Option("--age")
-                {
-                    Argument = new Argument<int>()
-                }
+                new Option<string>("--name"),
+                new Option<int>("--age")
             };
             command.Handler = CommandHandler.Create<string, int>((name, age) =>
             {
@@ -247,10 +201,7 @@ public async Task Nullable_parameters_are_bound_to_correct_value_when_option_is_
 
             var command = new Command("command")
             {
-                new Option("--age")
-                {
-                    Argument = new Argument<int?>()
-                }
+                new Option<int?>("--age")
             };
             command.Handler = CommandHandler.Create<int?>(age =>
             {
@@ -270,10 +221,7 @@ public async Task Nullable_parameters_are_bound_to_null_when_option_is_not_speci
 
             var command = new Command("command")
             {
-                new Option("--age")
-                {
-                    Argument = new Argument<int?>()
-                }
+                new Option<int?>("--age")
             };
             command.Handler = CommandHandler.Create<int?>(age =>
             {
@@ -295,10 +243,7 @@ public async Task Method_parameters_of_types_having_constructors_accepting_a_sin
 
             var command = new Command("command")
             {
-                new Option("--dir")
-                {
-                    Argument = new Argument<DirectoryInfo>()
-                }
+                new Option<DirectoryInfo>("--dir")
             };
             command.Handler = CommandHandler.Create<DirectoryInfo>(dir =>
             {
@@ -317,10 +262,7 @@ public async Task Method_parameters_of_type_ParseResult_receive_the_current_Pars
 
             var command = new Command("command")
             {
-                new Option("-x")
-                {
-                    Argument = new Argument<int>()
-                }
+                new Option<int>("-x")
             };
             command.Handler = CommandHandler.Create<ParseResult>(result => { boundParseResult = result; });
 
@@ -351,10 +293,7 @@ public async Task Method_parameters_of_type_IConsole_receive_the_current_console
         {
             var command = new Command("command")
             {
-                new Option("-x")
-                {
-                    Argument = new Argument<int>()
-                }
+                new Option<int>("-x")
             };
             command.Handler = CommandHandler.Create<IConsole>(console => { console.Out.Write("Hello!"); });
 
@@ -370,10 +309,7 @@ public async Task Method_parameters_of_type_InvocationContext_receive_the_curren
 
             var command = new Command("command")
             {
-                new Option("-x")
-                {
-                    Argument = new Argument<int>()
-                }
+                new Option<int>("-x")
             };
             command.Handler = CommandHandler.Create<InvocationContext>(context => { boundContext = context; });
 
@@ -404,14 +340,8 @@ public async Task Method_parameters_on_the_invoked_member_method_are_bound_to_ma
 
             var command = new Command("command")
             {
-                new Option("--name")
-                {
-                    Argument = new Argument<string>()
-                },
-                new Option("--age")
-                {
-                    Argument = new Argument<int>()
-                }
+                new Option<string>("--name"),
+                new Option<int>("--age")
             };
             command.Handler = CommandHandler.Create((ExecuteTestDelegate)testClass.Execute);
 
@@ -428,14 +358,8 @@ public async Task Method_parameters_on_the_invoked_member_method_are_bound_to_ma
 
             var command = new Command("command")
             {
-                new Option("--name")
-                {
-                    Argument = new Argument<string>()
-                },
-                new Option("--age")
-                {
-                    Argument = new Argument<int>()
-                }
+                new Option<string>("--name"),
+                new Option<int>("--age")
             };
             command.Handler = CommandHandler.Create(
                 testClass.GetType().GetMethod(nameof(ExecuteTestClass.Execute)),
diff --git a/src/System.CommandLine.Tests/OptionTests.cs b/src/System.CommandLine.Tests/OptionTests.cs
index c36edbc91..5be21a863 100644
--- a/src/System.CommandLine.Tests/OptionTests.cs
+++ b/src/System.CommandLine.Tests/OptionTests.cs
@@ -209,15 +209,9 @@ public void When_options_use_different_prefixes_they_still_work(string prefix)
         {
             var rootCommand = new RootCommand
                               {
-                                  new Option(prefix + "a")
-                                  {
-                                      Argument = new Argument<string>()
-                                  },
+                                  new Option<string>(prefix + "a"),
                                   new Option(prefix + "b"),
-                                  new Option(prefix + "c")
-                                  {
-                                      Argument = new Argument<string>()
-                                  }
+                                  new Option<string>(prefix + "c")
                               };
             var result = rootCommand.Parse(prefix + "c value-for-c " + prefix + "a value-for-a");
 
@@ -239,56 +233,20 @@ public void When_option_not_explicitly_provides_help_will_use_default_help()
         [Fact]
         public void Argument_takes_option_alias_as_its_name_when_it_is_not_provided()
         {
-            var command = new Option("--alias")
-            {
-                Argument = new Argument
-                {
-                    Arity = ArgumentArity.ZeroOrOne
-                }
-            };
+            var command = new Option("--alias", arity: ArgumentArity.ZeroOrOne);
 
-            command.Argument.Name.Should().Be("alias");
+            command.ArgumentName.Should().Be("alias");
         }
 
         [Fact]
         public void Argument_retains_name_when_it_is_provided()
         {
-            var option = new Option("-alias")
+            var option = new Option("-alias", arity: ArgumentArity.ZeroOrOne)
             {
-                Argument = new Argument
-                {
-                    Name = "arg",
-                    Arity = ArgumentArity.ZeroOrOne
-                }
+                ArgumentName = "arg"
             };
 
-            option.Argument.Name.Should().Be("arg");
-        }
-
-        [Fact]
-        public void Option_T_Argument_returns_an_Argument_T_when_not_explicitly_initialized()
-        {
-            var option = new Option<int>("-i");
-
-            option.Argument.Should().BeOfType<Argument<int>>();
-        }
-
-        [Theory]
-        [InlineData(typeof(Argument))]
-        [InlineData(typeof(Argument<string>))]
-        public void Option_T_Argument_cannot_be_set_to_Argument_of_incorrect_type(Type argumentType)
-        {
-            var option = new Option<int>("i");
-
-            var argument = Activator.CreateInstance(argumentType);
-
-            option.Invoking(o => o.Argument = (Argument) argument)
-                  .Should()
-                  .Throw<ArgumentException>()
-                  .Which
-                  .Message
-                  .Should()
-                  .Be($"Argument must be of type {typeof(Argument<int>)} but was {argument.GetType()}");
+            option.ArgumentName.Should().Be("arg");
         }
 
         [Fact]
@@ -310,18 +268,14 @@ public void Option_T_default_value_can_be_set()
         [Fact]
         public void Option_T_default_value_is_validated()
         {
-            var arg = new Argument<int>(() => 123);
-            arg.AddValidator( symbol =>
+            var option = new Option<int>("-x", () => 123);
+            option.AddValidator( symbol =>
                     symbol.Tokens
                     .Select(t => t.Value)
                     .Where(v => v == "123")
                     .Select(x => "ERR")
                     .FirstOrDefault());
 
-            var option = new Option("-x")
-            { 
-                Argument = arg
-            };
 
             option
                 .Parse("-x 123")
diff --git a/src/System.CommandLine.Tests/ParseDiagramTests.cs b/src/System.CommandLine.Tests/ParseDiagramTests.cs
index ed9022264..3c2acd4e6 100644
--- a/src/System.CommandLine.Tests/ParseDiagramTests.cs
+++ b/src/System.CommandLine.Tests/ParseDiagramTests.cs
@@ -17,13 +17,7 @@ public void Parse_result_diagram_helps_explain_parse_operation()
                 new Command(
                     "the-command")
                   {
-                        new Option("-x")
-                        {
-                            Argument = new Argument
-                            {
-                                Arity = ArgumentArity.ExactlyOne
-                            }
-                        },
+                        new Option("-x", arity: ArgumentArity.ExactlyOne),
                         new Option("-y"),
                         new Argument
                         {
@@ -58,10 +52,7 @@ public void Parse_diagram_shows_type_conversion_errors()
         {
             var command = new RootCommand
             {
-                new Option("-f")
-                {
-                    Argument = new Argument<int>()
-                }
+                new Option<int>("-f")
             };
 
             var result = command.Parse("-f not-an-int");
@@ -76,18 +67,9 @@ public void Parse_diagram_identifies_options_where_default_values_have_been_appl
         {
             var rootCommand = new RootCommand
             {
-                new Option(new[] { "-h", "--height" })
-                {
-                    Argument = new Argument<int>(getDefaultValue: () => 10)
-                },
-                new Option(new[] { "-w", "--width" })
-                {
-                    Argument = new Argument<int>(getDefaultValue: () => 15)
-                },
-                new Option(new[] { "-c", "--color" })
-                {
-                    Argument = new Argument<ConsoleColor>(() => ConsoleColor.Cyan)
-                }
+                new Option<int>(new[] { "-h", "--height" }, () => 10),
+                new Option<int>(new[] { "-w", "--width" }, () => 15),
+                new Option<ConsoleColor>(new[] { "-c", "--color" }, () => ConsoleColor.Cyan)
             };
 
             var result = rootCommand.Parse("-w 9000");
diff --git a/src/System.CommandLine.Tests/ParserTests.MultipleArguments.cs b/src/System.CommandLine.Tests/ParserTests.MultipleArguments.cs
index cad661eec..074f16ccc 100644
--- a/src/System.CommandLine.Tests/ParserTests.MultipleArguments.cs
+++ b/src/System.CommandLine.Tests/ParserTests.MultipleArguments.cs
@@ -88,10 +88,7 @@ public void When_multiple_arguments_are_present_then_their_order_relative_to_sib
                     new Argument<string> { Name = "first" },
                     new Argument<string> { Name = "second" },
                     new Argument<string[]> { Name = "third" },
-                    new Option("--verbose")
-                    {
-                        Argument = new Argument<bool>()
-                    }
+                    new Option<bool>("--verbose")
                 };
 
                 var parseResult = command.Parse(commandLine);
diff --git a/src/System.CommandLine.Tests/ParserTests.MultiplePositions.cs b/src/System.CommandLine.Tests/ParserTests.MultiplePositions.cs
index f287615e6..292633a75 100644
--- a/src/System.CommandLine.Tests/ParserTests.MultiplePositions.cs
+++ b/src/System.CommandLine.Tests/ParserTests.MultiplePositions.cs
@@ -73,10 +73,7 @@ public void When_an_argument_is_shared_between_an_outer_and_inner_command_then_s
             [InlineData("outer inner --the-option xyz")]
             public void An_option_can_be_specified_in_more_than_one_position(string commandLine)
             {
-                var option = new Option("--the-option")
-                {
-                    Argument = new Argument<string>()
-                };
+                var option = new Option<string>("--the-option");
 
                 var command = new Command("outer")
                 {
@@ -104,10 +101,7 @@ public void An_option_can_be_specified_in_more_than_one_position(string commandL
             [InlineData("outer inner --the-option xyz")]
             public void When_an_option_is_shared_between_an_outer_and_inner_command_then_specifying_in_one_does_not_result_in_error_on_other(string commandLine)
             {
-                var option = new Option("--the-option")
-                {
-                    Argument = new Argument<string>()
-                };
+                var option = new Option<string>("--the-option");
 
                 var command = new Command("outer")
                 {
@@ -136,10 +130,7 @@ public void When_an_option_is_shared_between_an_outer_and_inner_command_then_spe
                     {
                     })
                 };
-                reusedCommand.Add(new Option("--the-option")
-                {
-                    Argument = new Argument<string>()
-                });
+                reusedCommand.Add(new Option<string>("--the-option"));
 
                 var outer = new Command("outer")
                 {
diff --git a/src/System.CommandLine.Tests/ParserTests.cs b/src/System.CommandLine.Tests/ParserTests.cs
index b8a8169bf..fdef7b51e 100644
--- a/src/System.CommandLine.Tests/ParserTests.cs
+++ b/src/System.CommandLine.Tests/ParserTests.cs
@@ -110,15 +110,9 @@ public void Two_options_are_parsed_correctly()
         [Fact]
         public void Parse_result_contains_arguments_to_options()
         {
-            var optionOne = new Option(new[] { "-o", "--one" })
-            {
-                Argument = new Argument { Arity = ArgumentArity.ExactlyOne }
-            };
+            var optionOne = new Option(new[] { "-o", "--one" }, arity: ArgumentArity.ExactlyOne);
 
-            var optionTwo = new Option(new[] { "-t", "--two" })
-            {
-                Argument = new Argument { Arity = ArgumentArity.ExactlyOne }
-            };
+            var optionTwo = new Option(new[] { "-t", "--two" }, arity: ArgumentArity.ExactlyOne);
 
             var parser = new Parser(
                 optionOne,
@@ -207,13 +201,7 @@ public void The_portion_of_the_command_line_following_a_double_dash_is_accessibl
         [Fact]
         public void Short_form_options_can_be_specified_using_equals_delimiter()
         {
-            var option = new Option("-x")
-            {
-                Argument = new Argument
-                {
-                    Arity = ArgumentArity.ExactlyOne
-                }
-            };
+            var option = new Option("-x", arity: ArgumentArity.ExactlyOne);
 
             var result = option.Parse("-x=some-value");
 
@@ -226,13 +214,7 @@ public void Short_form_options_can_be_specified_using_equals_delimiter()
         public void Long_form_options_can_be_specified_using_equals_delimiter()
         {
             var option = 
-                new Option("--hello")
-                {
-                    Argument = new Argument
-                    {
-                        Arity = ArgumentArity.ExactlyOne
-                    }
-                };
+                new Option("--hello", arity: ArgumentArity.ExactlyOne);
 
             var result = option.Parse("--hello=there");
 
@@ -244,13 +226,7 @@ public void Long_form_options_can_be_specified_using_equals_delimiter()
         [Fact]
         public void Short_form_options_can_be_specified_using_colon_delimiter()
         {
-            var option = new Option("-x")
-            {
-                Argument = new Argument
-                {
-                    Arity = ArgumentArity.ExactlyOne
-                }
-            };
+            var option = new Option("-x", arity: ArgumentArity.ExactlyOne);
 
             var result = option.Parse("-x:some-value");
 
@@ -262,13 +238,7 @@ public void Short_form_options_can_be_specified_using_colon_delimiter()
         [Fact]
         public void Long_form_options_can_be_specified_using_colon_delimiter()
         {
-            var option = new Option("--hello")
-            {
-                Argument = new Argument
-                {
-                    Arity = ArgumentArity.ExactlyOne
-                }
-            };
+            var option = new Option("--hello", arity: ArgumentArity.ExactlyOne);
 
             var result = option.Parse("--hello:there");
 
@@ -365,10 +335,7 @@ public void Options_do_not_get_unbundled_unless_all_resulting_options_would_be_v
         [Fact]
         public void Required_option_arguments_are_not_unbundled()
         {
-            var optionA = new Option("-a")
-            {
-                Argument = new Argument<string>()
-            };
+            var optionA = new Option<string>("-a");
             var optionB = new Option("-b");
             var optionC = new Option("-c");
 
@@ -391,13 +358,7 @@ public void Required_option_arguments_are_not_unbundled()
         [Fact]
         public void Optional_option_arguments_are_unbundled()
         {
-            var optionA = new Option("-a")
-            {
-                Argument = new Argument<string>
-                {
-                    Arity = ArgumentArity.ZeroOrOne
-                }
-            };
+            var optionA = new Option<string>("-a", arity: ArgumentArity.ZeroOrOne);
             var optionB = new Option("-b");
             var optionC = new Option("-c");
 
@@ -420,20 +381,8 @@ public void Optional_option_arguments_are_unbundled()
         public void Last_bundled_option_can_accept_argument_with_no_separator()
         {
             var optionA = new Option("-a");
-            var optionB = new Option("-b")
-            {
-                Argument = new Argument<string>
-                {
-                    Arity = ArgumentArity.ZeroOrOne
-                }
-            };
-            var optionC = new Option("-c") 
-            {
-                Argument = new Argument<string>
-                {
-                    Arity = ArgumentArity.ExactlyOne
-                }
-            };
+            var optionB = new Option<string>("-b", arity: ArgumentArity.ZeroOrOne);
+            var optionC = new Option<string>("-c", arity: ArgumentArity.ExactlyOne);
 
             var command = new RootCommand
             {
@@ -456,20 +405,8 @@ public void Last_bundled_option_can_accept_argument_with_no_separator()
         public void Last_bundled_option_can_accept_argument_with_equals_separator()
         {
             var optionA = new Option("-a");
-            var optionB = new Option("-b")
-            {
-                Argument = new Argument<string>
-                {
-                    Arity = ArgumentArity.ZeroOrOne
-                }
-            };
-            var optionC = new Option("-c") 
-            {
-                Argument = new Argument<string>
-                {
-                    Arity = ArgumentArity.ExactlyOne
-                }
-            };
+            var optionB = new Option<string>("-b", arity: ArgumentArity.ZeroOrOne);
+            var optionC = new Option<string>("-c", arity: ArgumentArity.ExactlyOne);
 
             var command = new RootCommand
             {
@@ -492,20 +429,8 @@ public void Last_bundled_option_can_accept_argument_with_equals_separator()
         public void Last_bundled_option_can_accept_argument_with_colon_separator()
         {
             var optionA = new Option("-a");
-            var optionB = new Option("-b")
-            {
-                Argument = new Argument<string>
-                {
-                    Arity = ArgumentArity.ZeroOrOne
-                }
-            };
-            var optionC = new Option("-c") 
-            {
-                Argument = new Argument<string>
-                {
-                    Arity = ArgumentArity.ExactlyOne
-                }
-            };
+            var optionB = new Option<string>("-b", arity: ArgumentArity.ZeroOrOne);
+            var optionC = new Option<string>("-c", arity: ArgumentArity.ExactlyOne);
 
             var command = new RootCommand
             {
@@ -528,20 +453,8 @@ public void Last_bundled_option_can_accept_argument_with_colon_separator()
         public void Invalid_char_in_bundle_causes_rest_to_be_interpreted_as_value()
         {
             var optionA = new Option("-a");
-            var optionB = new Option("-b")
-            {
-                Argument = new Argument<string>
-                {
-                    Arity = ArgumentArity.ZeroOrOne
-                }
-            };
-            var optionC = new Option("-c") 
-            {
-                Argument = new Argument<string>
-                {
-                    Arity = ArgumentArity.ExactlyOne
-                }
-            };
+            var optionB = new Option<string>("-b", arity: ArgumentArity.ZeroOrOne);
+            var optionC = new Option<string>("-c", arity: ArgumentArity.ExactlyOne);
 
             var command = new RootCommand
             {
@@ -566,20 +479,8 @@ public void Invalid_char_in_bundle_causes_rest_to_be_interpreted_as_value()
         [Fact]
         public void Parser_root_Options_can_be_specified_multiple_times_and_their_arguments_are_collated()
         {
-            var animalsOption = new Option(new[] { "-a", "--animals" })
-            {
-                Argument = new Argument
-                {
-                    Arity = ArgumentArity.ZeroOrMore
-                }, Description = ""
-            };
-            var vegetablesOption = new Option(new[] { "-v", "--vegetables" })
-            {
-                Argument = new Argument
-                {
-                    Arity = ArgumentArity.ZeroOrMore
-                }, Description = ""
-            };
+            var animalsOption = new Option(new[] { "-a", "--animals" }, arity: ArgumentArity.ZeroOrMore);
+            var vegetablesOption = new Option(new[] { "-v", "--vegetables" }, arity: ArgumentArity.ZeroOrMore);
             var parser = new Parser(
                 animalsOption,
                 vegetablesOption);
@@ -602,20 +503,9 @@ public void Parser_root_Options_can_be_specified_multiple_times_and_their_argume
         [Fact]
         public void Options_can_be_specified_multiple_times_and_their_arguments_are_collated()
         {
-            var animalsOption = new Option(new[] { "-a", "--animals" })
-            {
-                Argument = new Argument
-                {
-                    Arity = ArgumentArity.ZeroOrMore
-                }.FromAmong("dog", "cat", "sheep"), Description = ""
-            };
-            var vegetablesOption = new Option(new[] { "-v", "--vegetables" })
-            {
-                Argument = new Argument
-                {
-                    Arity = ArgumentArity.ZeroOrMore
-                }, Description = ""
-            };
+            var animalsOption = new Option(new[] { "-a", "--animals" }, arity: ArgumentArity.ZeroOrMore)
+                .FromAmong("dog", "cat", "sheep");
+            var vegetablesOption = new Option(new[] { "-v", "--vegetables" }, arity: ArgumentArity.ZeroOrMore);
             var parser = new Parser(
                 new Command("the-command") {
                     animalsOption,
@@ -640,20 +530,8 @@ public void Options_can_be_specified_multiple_times_and_their_arguments_are_coll
         [Fact]
         public void When_a_Parser_root_option_is_not_respecified_but_limit_is_not_reached_then_the_following_token_is_used_as_value()
         {
-            var animalsOption = new Option(new[] { "-a", "--animals" })
-            {
-                Argument = new Argument
-                {
-                    Arity = ArgumentArity.ZeroOrMore
-                }, Description = ""
-            };
-            var vegetablesOption = new Option(new[] { "-v", "--vegetables" })
-            {
-                Argument = new Argument
-                {
-                    Arity = ArgumentArity.ZeroOrMore
-                }, Description = ""
-            };
+            var animalsOption = new Option(new[] { "-a", "--animals" }, arity: ArgumentArity.ZeroOrMore);
+            var vegetablesOption = new Option(new[] { "-v", "--vegetables" }, arity: ArgumentArity.ZeroOrMore);
 
             var parser = new Parser(
                 animalsOption,
@@ -684,20 +562,8 @@ public void When_a_Parser_root_option_is_not_respecified_but_limit_is_not_reache
         [Fact]
         public void When_a_Parser_root_option_is_not_respecified_and_limit_is_reached_then_the_following_token_is_unmatched()
         {
-            var animalsOption = new Option(new[] { "-a", "--animals" })
-            {
-                Argument = new Argument
-                {
-                    Arity = ArgumentArity.ZeroOrOne
-                }, Description = ""
-            };
-            var vegetablesOption = new Option(new[] { "-v", "--vegetables" })
-            {
-                Argument = new Argument
-                {
-                    Arity = ArgumentArity.ZeroOrMore
-                }, Description = ""
-            };
+            var animalsOption = new Option(new[] { "-a", "--animals" }, arity: ArgumentArity.ZeroOrOne);
+            var vegetablesOption = new Option(new[] { "-v", "--vegetables" }, arity: ArgumentArity.ZeroOrMore);
 
             var parser = new Parser(
                 animalsOption,
@@ -726,20 +592,8 @@ public void When_a_Parser_root_option_is_not_respecified_and_limit_is_reached_th
         [Fact]
         public void When_an_option_is_not_respecified_but_limit_is_not_reached_then_the_following_token_is_considered_as_value()
         {
-            var animalsOption = new Option(new[] { "-a", "--animals" })
-            {
-                Argument = new Argument
-                {
-                    Arity = ArgumentArity.ZeroOrMore
-                }
-            };
-            var vegetablesOption = new Option(new[] { "-v", "--vegetables" })
-            {
-                Argument = new Argument
-                {
-                    Arity = ArgumentArity.ZeroOrMore
-                }
-            };
+            var animalsOption = new Option(new[] { "-a", "--animals" }, arity: ArgumentArity.ZeroOrMore);
+            var vegetablesOption = new Option(new[] { "-v", "--vegetables" }, arity: ArgumentArity.ZeroOrMore);
             var parser = new Parser(
                 new Command("the-command")
                 {
@@ -774,21 +628,9 @@ public void When_an_option_is_not_respecified_but_limit_is_not_reached_then_the_
         [Fact]
         public void When_an_option_is_not_respecified_but_limit_is_reached_then_the_following_token_is_considered_an_argument_to_the_parent_command()
         {
-            var animalsOption = new Option(new[] { "-a", "--animals" })
-            {
-                Argument = new Argument
-                {
-                    Arity = ArgumentArity.ZeroOrOne
-                }
-            };
+            var animalsOption = new Option(new[] { "-a", "--animals" }, arity: ArgumentArity.ZeroOrOne);
 
-            var vegetablesOption = new Option(new[] { "-v", "--vegetables" })
-            {
-                Argument = new Argument
-                {
-                    Arity = ArgumentArity.ZeroOrMore
-                }
-            };
+            var vegetablesOption = new Option(new[] { "-v", "--vegetables" }, arity: ArgumentArity.ZeroOrOne);
             
             var parser = new Parser(
                 new Command("the-command")
@@ -826,20 +668,8 @@ public void Command_with_multiple_options_is_parsed_correctly()
         {
             var option = new Command("outer")
             {
-                new Option("--inner1")
-                {
-                    Argument = new Argument
-                    {
-                        Arity = ArgumentArity.ExactlyOne
-                    }
-                },
-                new Option("--inner2")
-                {
-                    Argument = new Argument
-                    {
-                        Arity = ArgumentArity.ExactlyOne
-                    }
-                }
+                new Option("--inner1", arity: ArgumentArity.ExactlyOne),
+                new Option("--inner2", arity: ArgumentArity.ExactlyOne)
             };
 
             var parser = new Parser(option);
@@ -866,10 +696,7 @@ public void Relative_order_of_arguments_and_options_within_a_command_does_not_ma
             var command = new Command("move")
             {
                 new Argument<string[]>(),
-                new Option("-X")
-                {
-                    Argument = new Argument<string>()
-                }
+                new Option<string>("-X")
             };
 
             // option before args
@@ -912,14 +739,8 @@ public void Original_order_of_tokens_is_preserved_in_ParseResult_Tokens(string c
             var command = new Command("the-command")
                           {
                               new Argument<string[]>(),
-                              new Option("--one")
-                              {
-                                  Argument = new Argument<string>()
-                              },
-                              new Option("--many")
-                              {
-                                  Argument = new Argument<string[]>()
-                              }
+                              new Option<string>("--one"),
+                              new Option<string[]>("--many")
                           };
 
             var result = command.Parse(commandLine);
@@ -1039,10 +860,7 @@ public void When_child_option_will_not_accept_arg_then_parent_can()
         [Fact]
         public void When_parent_option_will_not_accept_arg_then_child_can()
         {
-            var option = new Option("-x")
-            {
-                Argument = new Argument<string>()
-            };
+            var option = new Option<string>("-x");
             var command = new Command("the-command")
             {
                 option
@@ -1198,10 +1016,7 @@ public void Subsequent_occurrences_of_tokens_matching_command_names_are_parsed_a
                 new Command("complete")
                 {
                     new Argument<string>(),
-                    new Option("--position")
-                    {
-                        Argument = new Argument<int>()
-                    }
+                    new Option<int>("--position")
                 }
             };
 
@@ -1223,13 +1038,7 @@ public void A_root_command_can_be_omitted_from_the_parsed_args()
                           {
                               new Command("inner")
                               {
-                                  new Option("-x")
-                                  {
-                                      Argument = new Argument
-                                      {
-                                          Arity = ArgumentArity.ExactlyOne
-                                      }
-                                  }
+                                  new Option("-x", arity: ArgumentArity.ExactlyOne)
                               }
                           };
 
@@ -1246,13 +1055,7 @@ public void A_root_command_can_match_a_full_path_to_an_executable()
             {
                 new Command("inner")
                 {
-                    new Option("-x")
-                    {
-                        Argument = new Argument
-                        {
-                            Arity = ArgumentArity.ExactlyOne
-                        }
-                    }
+                    new Option("-x", arity: ArgumentArity.ExactlyOne)
                 }
             };
 
@@ -1270,13 +1073,7 @@ public void A_renamed_RootCommand_can_be_omitted_from_the_parsed_args()
                               {
                                   new Command("inner")
                                   {
-                                      new Option("-x")
-                                      {
-                                          Argument = new Argument
-                                          {
-                                              Arity = ArgumentArity.ExactlyOne
-                                          }
-                                      }
+                                      new Option("-x", arity: ArgumentArity.ExactlyOne)
                                   }
                               };
             rootCommand.Name = "outer";
@@ -1354,10 +1151,7 @@ public void When_an_option_with_a_default_value_is_not_matched_then_the_option_c
         {
             var command = new Command("command");
             command.AddOption(
-                new Option(new[] { "-o", "--option" })
-                {
-                    Argument = new Argument<string>(() => "the-default")
-                });
+                new Option<string>(new[] { "-o", "--option" }, () => "the-default"));
 
             ParseResult result = command.Parse("command");
 
@@ -1370,10 +1164,7 @@ public void When_an_option_with_a_default_value_is_not_matched_then_the_option_c
         [Fact]
         public void When_an_option_with_a_default_value_is_not_matched_then_the_option_result_is_implicit()
         {
-            var option = new Option(new[]{ "-o", "--option" })
-            {
-                Argument = new Argument<string>(() => "the-default")
-            };
+            var option = new Option<string>(new[]{ "-o", "--option" }, () => "the-default");
 
             var command = new Command("command")
             {
@@ -1571,13 +1362,7 @@ public void Options_can_have_the_same_alias_differentiated_only_by_prefix()
         [InlineData("-x:\"\"", "")]
         public void When_an_argument_is_enclosed_in_double_quotes_its_value_has_the_quotes_removed(string input, string expected)
         {
-            var option = new Option("-x")
-            {
-                Argument = new Argument
-                {
-                    Arity = ArgumentArity.ZeroOrMore
-                }
-            };
+            var option = new Option("-x", arity: ArgumentArity.ZeroOrMore);
 
             var parseResult = option.Parse(input);
 
@@ -1597,23 +1382,10 @@ public void Arguments_can_start_with_prefixes_that_make_them_look_like_options(s
         {
             var command = new Command("command")
             {
-                new Option("-x")
-                {
-                    Argument = new Argument
-                    {
-                        Arity = ArgumentArity.ZeroOrOne
-                    }
-                },
-                new Option("-z")
-                {
-                    Argument = new Argument
-                    {
-                        Arity = ArgumentArity.ZeroOrOne
-                    }
-                }
+                new Option("-x", arity: ArgumentArity.ZeroOrOne),
+                new Option("-z", arity: ArgumentArity.ZeroOrOne)
             };
 
-
             var result = command.Parse(input);
 
             var valueForOption = result.ValueForOption("-x");
@@ -1628,20 +1400,8 @@ public void Arguments_can_match_the_aliases_of_sibling_options(string input)
         {
             var command = new Command("command")
             {
-                new Option("-x")
-                {
-                    Argument = new Argument
-                    {
-                        Arity = ArgumentArity.ZeroOrOne
-                    }
-                },
-                new Option("-y")
-                {
-                    Argument = new Argument
-                    {
-                        Arity = ArgumentArity.ZeroOrOne
-                    }
-                }
+                new Option("-x", arity: ArgumentArity.ZeroOrOne),
+                new Option("-y", arity: ArgumentArity.ZeroOrOne)
             };
 
             var result = command.Parse(input);
@@ -1684,10 +1444,7 @@ public void Boolean_options_with_no_argument_specified_do_not_match_subsequent_a
         {
             var command = new Command("command")
             {
-                new Option("-v")
-                {
-                    Argument = new Argument<bool>()
-                }
+                new Option<bool>("-v")
             };
 
             var result = command.Parse("-v an-argument");
@@ -1702,22 +1459,8 @@ public void When_a_command_line_has_unmatched_tokens_they_are_not_applied_to_sub
             {
                 TreatUnmatchedTokensAsErrors = false
             };
-            command.AddOption(
-                new Option("-x")
-                {
-                    Argument = new Argument
-                    {
-                        Arity = ArgumentArity.ExactlyOne
-                    }
-                });
-            command.AddOption(
-                new Option("-y")
-                {
-                    Argument = new Argument
-                    {
-                        Arity = ArgumentArity.ExactlyOne
-                    }
-                });
+            command.AddOption(new Option("-x", arity: ArgumentArity.ExactlyOne));
+            command.AddOption(new Option("-y", arity: ArgumentArity.ExactlyOne));
 
             var result = command.Parse("-x 23 unmatched-token -y 42");
 
@@ -1830,13 +1573,7 @@ public void When_command_arguments_are_greater_than_maximum_arity_then_an_error_
         [Fact]
         public void Option_argument_arity_can_be_a_fixed_value_greater_than_1()
         {
-            var option = new Option("-x")
-            {
-                Argument = new Argument
-                {
-                    Arity = new ArgumentArity(3, 3)
-                }
-            };
+            var option = new Option("-x", arity: new ArgumentArity(3, 3));
 
             var command = new Command("the-command")
             {
@@ -1856,13 +1593,7 @@ public void Option_argument_arity_can_be_a_fixed_value_greater_than_1()
         [Fact]
         public void Option_argument_arity_can_be_a_range_with_a_lower_bound_greater_than_1()
         {
-            var option = new Option("-x")
-            {
-                Argument = new Argument
-                {
-                    Arity = new ArgumentArity(3, 5)
-                }
-            };
+            var option = new Option("-x", arity: new ArgumentArity(3, 5));
 
             var command = new Command("the-command")
             {
@@ -1892,13 +1623,7 @@ public void Option_argument_arity_can_be_a_range_with_a_lower_bound_greater_than
         [Fact]
         public void When_option_arguments_are_fewer_than_minimum_arity_then_an_error_is_returned()
         {
-            var option = new Option("-x")
-            {
-                Argument = new Argument
-                {
-                    Arity = new ArgumentArity(2, 3)
-                }
-            };
+            var option = new Option("-x", arity: new ArgumentArity(2, 3));
 
             var command = new Command("the-command")
             {
@@ -1918,13 +1643,7 @@ public void When_option_arguments_are_greater_than_maximum_arity_then_an_error_i
         {
             var command = new Command("the-command")
             {
-                new Option("-x")
-                {
-                    Argument = new Argument
-                    {
-                        Arity = new ArgumentArity(2, 3)
-                    }
-                }
+                new Option("-x", arity: new ArgumentArity(2, 3))
             };
 
             command.Parse("-x 1 2 3 4")
@@ -1950,17 +1669,11 @@ public void Argument_with_custom_type_converter_can_be_bound()
         [Fact]
         public void Argument_with_custom_collection_type_converter_can_be_bound()
         {
-            var option = new Option("--value")
-            {
-                Argument = new Argument<CollectionWithCustomTypeConverter>
-                {
-                    Arity = ArgumentArity.ExactlyOne
-                }
-            };
+            var option = new Option<CollectionWithCustomTypeConverter>("--value", arity: ArgumentArity.ExactlyOne);
 
             var parseResult = option.Parse("--value a;b;c");
 
-            var instance = (CollectionWithCustomTypeConverter)parseResult.ValueForOption("--value");
+            CollectionWithCustomTypeConverter instance = parseResult.ValueForOption(option);
 
             instance.Should().BeEquivalentTo("a", "b", "c");
         }
@@ -2046,9 +1759,7 @@ public class CollectionWithCustomTypeConverter : List<string>
         {
             public CollectionWithCustomTypeConverter(IEnumerable<string> values)
                 : base(values)
-            {
-
-            }
+            { }
         }
       
         public class CustomCollectionTypeConverter : TypeConverter
diff --git a/src/System.CommandLine.Tests/ParsingValidationTests.cs b/src/System.CommandLine.Tests/ParsingValidationTests.cs
index faab26faa..aedd99914 100644
--- a/src/System.CommandLine.Tests/ParsingValidationTests.cs
+++ b/src/System.CommandLine.Tests/ParsingValidationTests.cs
@@ -26,14 +26,8 @@ public ParsingValidationTests(ITestOutputHelper output)
         public void When_an_option_accepts_only_specific_arguments_but_a_wrong_one_is_supplied_then_an_informative_error_is_returned()
         {
             var parser = new Parser(
-                new Option("-x")
-                {
-                    Argument = new Argument
-                        {
-                            Arity = ArgumentArity.ExactlyOne 
-                        }
-                        .FromAmong("this", "that", "the-other-thing")
-                });
+                new Option("-x", arity: ArgumentArity.ExactlyOne)
+                    .FromAmong("this", "that", "the-other-thing"));
 
             var result = parser.Parse("-x none-of-those");
 
@@ -47,13 +41,8 @@ public void When_an_option_accepts_only_specific_arguments_but_a_wrong_one_is_su
         [Fact]
         public void When_an_option_has_en_error_then_the_error_has_a_reference_to_the_option()
         {
-            var option = new Option("-x")
-            {
-                Argument = new Argument
-                {
-                    Arity = ArgumentArity.ExactlyOne
-                }.FromAmong("this", "that")
-            };
+            var option = new Option("-x", arity: ArgumentArity.ExactlyOne)
+                .FromAmong("this", "that");
 
             var parser = new Parser(option);
 
@@ -68,13 +57,7 @@ public void When_an_option_has_en_error_then_the_error_has_a_reference_to_the_op
         [Fact]
         public void When_a_required_argument_is_not_supplied_then_an_error_is_returned()
         {
-            var parser = new Parser(new Option("-x")
-            {
-                Argument = new Argument
-                {
-                    Arity = ArgumentArity.ExactlyOne
-                }
-            });
+            var parser = new Parser(new Option("-x", arity: ArgumentArity.ExactlyOne));
 
             var result = parser.Parse("-x");
 
@@ -250,7 +233,7 @@ public void A_custom_validator_can_be_added_to_an_argument()
         public void Validators_on_global_options_are_executed_when_invoking_a_subcommand(string commandLine)
         {
             var option = new Option<FileInfo>("--file");
-            option.Argument.AddValidator(r =>
+            option.AddValidator(r =>
             {
                 return "Invoked validator";
             });
@@ -266,7 +249,7 @@ public void Validators_on_global_options_are_executed_when_invoking_a_subcommand
 
             result.Errors
                   .Should()
-                  .ContainSingle(e => e.SymbolResult.Symbol == option.Argument)
+                  .ContainSingle(e => e.SymbolResult.Symbol == option)
                   .Which
                   .Message
                   .Should()
@@ -601,13 +584,7 @@ public void A_command_argument_with_multiple_FileSystemInfos_can_be_invalid_base
                     {
                         Arity = ArgumentArity.ZeroOrMore
                     }.ExistingOnly(),
-                    new Option("--to")
-                    {
-                        Argument = new Argument
-                        {
-                            Arity = ArgumentArity.ExactlyOne
-                        }
-                    }
+                    new Option("--to", arity: ArgumentArity.ExactlyOne)
                 };
 
                 var path = NonexistentPath();
@@ -806,13 +783,7 @@ public void A_command_with_subcommands_is_valid_to_invoke_if_it_has_a_handler()
         public void When_an_option_is_specified_more_than_once_but_only_allowed_once_then_an_informative_error_is_returned()
         {
             var parser = new Parser(
-                new Option("-x")
-                {
-                    Argument = new Argument
-                    {
-                        Arity = ArgumentArity.ExactlyOne
-                    }
-                });
+                new Option("-x", arity: ArgumentArity.ExactlyOne));
 
             var result = parser.Parse("-x 1 -x 2");
 
@@ -826,10 +797,7 @@ public void When_an_option_is_specified_more_than_once_but_only_allowed_once_the
         public void When_arity_is_ExactlyOne_it_validates_against_extra_arguments()
         {
             var parser = new Parser(
-                new Option("-x")
-                {
-                    Argument = new Argument<int>()
-                });
+                new Option<int>("-x"));
 
             var result = parser.Parse("-x 1 -x 2");
 
@@ -843,10 +811,7 @@ public void When_arity_is_ExactlyOne_it_validates_against_extra_arguments()
         public void When_an_option_has_a_default_value_it_is_not_valid_to_specify_the_option_without_an_argument()
         {
             var parser = new Parser(
-                new Option("-x")
-                {
-                    Argument = new Argument<int>(() => 123)
-                });
+                new Option<int>("-x", () => 123));
 
             var result = parser.Parse("-x");
 
@@ -860,14 +825,8 @@ public void When_an_option_has_a_default_value_it_is_not_valid_to_specify_the_op
         public void When_an_option_has_a_default_value_then_the_default_should_apply_if_not_specified()
         {
             var parser = new Parser(
-                new Option("-x")
-                {
-                    Argument = (Argument) new Argument<int>(() => 123)
-                },
-                new Option("-y")
-                {
-                    Argument = (Argument) new Argument<int>(() => 456)
-                });
+                new Option<int>("-x", () => 123),
+                new Option<int>("-y", () => 456));
 
             var result = parser.Parse("");
 
diff --git a/src/System.CommandLine.Tests/ResponseFileTests.cs b/src/System.CommandLine.Tests/ResponseFileTests.cs
index 31cb0d4b7..e305c826f 100644
--- a/src/System.CommandLine.Tests/ResponseFileTests.cs
+++ b/src/System.CommandLine.Tests/ResponseFileTests.cs
@@ -61,10 +61,7 @@ public void When_response_file_is_specified_it_loads_options_with_arguments_from
             var result = new RootCommand
                          {
                              new Option("--flag"),
-                             new Option("--flag2")
-                             {
-                                 Argument = new Argument<int>()
-                             }
+                             new Option<int>("--flag2")
                          }
                 .Parse($"@{responseFile}");
 
@@ -172,10 +169,7 @@ public void Response_file_can_contain_blank_lines()
                 "123");
 
             var result = new CommandLineBuilder()
-                         .AddOption(new Option("--flag")
-                         {
-                             Argument = new Argument<int>()
-                         })
+                         .AddOption(new Option<int>("--flag"))
                          .Build()
                          .Parse($"@{responseFile}");
 
@@ -270,14 +264,8 @@ public void When_response_file_parse_as_space_separated_returns_expected_values(
 
             var rootCommand = new RootCommand
             {
-                new Option("--flag")
-                {
-                    Argument = new Argument<string>()
-                },
-                new Option("--flag2")
-                {
-                    Argument = new Argument<int>()
-                }
+                new Option<string>("--flag"),
+                new Option<int>("--flag2")
             };
             var parser = new CommandLineBuilder(rootCommand)
                          .ParseResponseFileAs(ResponseFileHandling.ParseArgsAsSpaceSeparated)
@@ -317,9 +305,9 @@ public void Response_files_can_refer_to_other_response_files()
             var file2 = ResponseFile($"@{file3}", "--two", "2");
             var file1 = ResponseFile("--one", "1", $"@{file2}");
 
-            var option1 = new Option("--one") { Argument = new Argument<int>() };
-            var option2 = new Option("--two") { Argument = new Argument<int>() };
-            var option3 = new Option("--three") { Argument = new Argument<int>() };
+            var option1 = new Option<int>("--one");
+            var option2 = new Option<int>("--two");
+            var option3 = new Option<int>("--three");
 
             var command = new RootCommand
                           {
@@ -342,8 +330,8 @@ public void When_response_file_options_or_arguments_contain_trailing_spaces_they
         {
             var responseFile = ResponseFile("--option1 ", "value1 ", "--option2\t", "2\t");
 
-            var option1 = new Option("--option1") { Argument = new Argument<string>() };
-            var option2 = new Option("--option2") { Argument = new Argument<int>() };
+            var option1 = new Option<string>("--option1");
+            var option2 = new Option<int>("--option2");
 
             var result = new RootCommand { option1, option2 }.Parse($"@{responseFile}");
             result.ValueForOption("--option1").Should().Be("value1");
@@ -355,8 +343,8 @@ public void When_response_file_options_or_arguments_contain_leading_spaces_they_
         {
             var responseFile = ResponseFile(" --option1", " value1", "\t--option2", "\t2");
 
-            var option1 = new Option("--option1") { Argument = new Argument<string>() };
-            var option2 = new Option("--option2") { Argument = new Argument<int>() };
+            var option1 = new Option<string>("--option1");
+            var option2 = new Option<int>("--option2");
 
             var result = new RootCommand { option1, option2 }.Parse($"@{responseFile}");
             result.ValueForOption("--option1").Should().Be("value1");
@@ -369,8 +357,8 @@ public void When_response_file_options_or_arguments_contain_trailing_and_leading
         {
             var responseFile = ResponseFile(" --option1 ", " value1 ", "\t--option2\t", "\t2\t");
 
-            var option1 = new Option("--option1") { Argument = new Argument<string>() };
-            var option2 = new Option("--option2") { Argument = new Argument<int>() };
+            var option1 = new Option<string>("--option1");
+            var option2 = new Option<int>("--option2");
 
             var result = new RootCommand { option1, option2 }.Parse($"@{responseFile}");
             result.ValueForOption("--option1").Should().Be("value1");
diff --git a/src/System.CommandLine.Tests/SuggestDirectiveTests.cs b/src/System.CommandLine.Tests/SuggestDirectiveTests.cs
index 64234d9ec..d80c963c1 100644
--- a/src/System.CommandLine.Tests/SuggestDirectiveTests.cs
+++ b/src/System.CommandLine.Tests/SuggestDirectiveTests.cs
@@ -255,10 +255,7 @@ public async Task It_does_not_repeat_suggestion_for_already_specified_bool_optio
         {
             var command = new RootCommand
             {
-                new Option("--bool-option")
-                {
-                    Argument = new Argument<bool>()
-                }
+                new Option<bool>("--bool-option")
             };
 
             var console = new TestConsole();
diff --git a/src/System.CommandLine.Tests/SuggestionTests.cs b/src/System.CommandLine.Tests/SuggestionTests.cs
index 92a9caa62..5bda333c3 100644
--- a/src/System.CommandLine.Tests/SuggestionTests.cs
+++ b/src/System.CommandLine.Tests/SuggestionTests.cs
@@ -24,14 +24,8 @@ public SuggestionTests(ITestOutputHelper output)
         [Fact]
         public void Option_GetSuggestions_returns_argument_suggestions_if_configured()
         {
-            var option = new Option("--hello")
-            {
-                Argument = new Argument
-                    {
-                        Arity = ArgumentArity.ExactlyOne,
-                        Suggestions = { "one", "two", "three" }
-                    }
-            };
+            var option = new Option("--hello", arity: ArgumentArity.ExactlyOne)
+                .AddSuggestions("one", "two", "three");
 
             var suggestions = option.GetSuggestions();
 
@@ -159,18 +153,12 @@ public void Command_GetSuggestions_with_text_to_match_orders_by_match_position_t
         public void When_an_option_has_a_default_value_it_will_still_be_suggested()
         {
             var parser = new Parser(
-                new Option("--apple", "kinds of apples")
-                {
-                    Argument = new Argument<string[]>("cortland")
-                },
-                new Option("--banana", "kinds of bananas")
+                new Option<string[]>("--apple", "kinds of apples")
                 {
-                    Argument = new Argument<string[]>()
+                    ArgumentName = "cortland"
                 },
-                new Option("--cherry", "kinds of cherries")
-                {
-                    Argument = new Argument<string>()
-                });
+                new Option<string[]>("--banana", "kinds of bananas"),
+                new Option<string>("--cherry", "kinds of cherries"));
 
             var result = parser.Parse("");
 
@@ -187,24 +175,13 @@ public void When_an_option_has_a_default_value_it_will_still_be_suggested()
         public void Command_Getsuggestions_can_access_ParseResult()
         {
             var parser = new Parser(
-                new Option("--origin")
+                new Option<string>("--origin"),
+                new Option<string>("--clone")
+                .AddSuggestions((parseResult, match) =>
                 {
-                    Argument = new Argument<string>()
-                },
-                new Option("--clone")
-                {
-                    Argument = new Argument<string>()
-                    {
-                        Suggestions =
-                        {
-                            (parseResult, match) =>
-                            {
-                                var opt1Value = parseResult?.ValueForOption<string>("--origin");
-                                return opt1Value != null ? new[] { opt1Value } : Array.Empty<string>();
-                            }
-                        }
-                    }
-                });
+                    var opt1Value = parseResult?.ValueForOption<string>("--origin");
+                    return opt1Value != null ? new[] { opt1Value } : Array.Empty<string>();
+                }));
 
             var result = parser.Parse("--origin test --clone ");
 
@@ -219,25 +196,13 @@ public void Command_Getsuggestions_can_access_ParseResult()
         public void Command_Getsuggestions_can_access_ParseResult_reverse_order()
         {
             var parser = new Parser(
-                new Option("--origin")
-                {
-                    Argument = new Argument<string>()
-                },
-                new Option("--clone")
+                new Option<string>("--origin"),
+                new Option<string>("--clone")
+                .AddSuggestions((parseResult, match) =>
                 {
-                    Argument = new Argument<string>()
-                    {
-                        Suggestions =
-                        {
-                            (parseResult, match) =>
-                            {
-                                var opt1Value = parseResult?.ValueForOption<string>("--origin");
-                                return opt1Value != null ? new[] { opt1Value } : Array.Empty<string>();
-                            }
-
-                        }
-                    }
-                });
+                    var opt1Value = parseResult?.ValueForOption<string>("--origin");
+                    return opt1Value != null ? new[] { opt1Value } : Array.Empty<string>();
+                }));
 
             var result = parser.Parse("--clone  --origin test");
 
@@ -346,10 +311,7 @@ public void When_a_subcommand_has_been_specified_then_its_sibling_options_with_a
             var command = new RootCommand("parent")
             {
                 new Command("child"),
-                new Option("--parent-option")
-                {
-                    Argument = new Argument<string>()
-                },
+                new Option<string>("--parent-option"),
                 new Argument<string>()
             };
 
@@ -370,10 +332,7 @@ public void When_a_subcommand_has_been_specified_then_its_child_options_will_be_
                 new Argument<string>(),
                 new Command("child")
                 {
-                    new Option("--child-option")
-                    {
-                        Argument = new Argument<string>()
-                    }
+                    new Option<string>("--child-option")
                 }
             };
 
@@ -453,16 +412,10 @@ public void An_option_can_be_hidden_from_suggestions_by_setting_IsHidden_to_true
         public void Parser_options_can_supply_context_sensitive_matches()
         {
             var parser = new Parser(
-                new Option("--bread")
-                {
-                    Argument = new Argument { Arity = ArgumentArity.ExactlyOne }
-                        .FromAmong("wheat", "sourdough", "rye")
-                },
-                new Option("--cheese")
-                {
-                    Argument = new Argument { Arity = ArgumentArity.ExactlyOne }
-                        .FromAmong("provolone", "cheddar", "cream cheese")
-                });
+                new Option("--bread", arity: ArgumentArity.ExactlyOne)
+                    .FromAmong("wheat", "sourdough", "rye"),
+                new Option("--cheese", arity: ArgumentArity.ExactlyOne)
+                    .FromAmong("provolone", "cheddar", "cream cheese"));
 
             var commandLine = "--bread";
             var result = parser.Parse(commandLine);
@@ -561,22 +514,10 @@ public void Argument_suggestions_can_be_based_on_the_proximate_option()
             var parser = new Parser(
                 new Command("outer")
                 {
-                    new Option("--one")
-                    {
-                        Argument = new Argument
-                            {
-                                Arity = ArgumentArity.ExactlyOne
-                            }
-                            .FromAmong("one-a", "one-b")
-                    },
-                    new Option("--two")
-                    {
-                        Argument = new Argument
-                            {
-                                Arity = ArgumentArity.ExactlyOne
-                            }
-                            .FromAmong("two-a", "two-b")
-                    }
+                    new Option("--one", arity: ArgumentArity.ExactlyOne)
+                        .FromAmong("one-a", "one-b"),
+                    new Option("--two", arity: ArgumentArity.ExactlyOne)
+                        .FromAmong("two-a", "two-b")
                 });
 
             var commandLine = "outer --two";
@@ -606,14 +547,8 @@ public void Suggestions_can_be_provided_in_the_absence_of_validation()
         {
             var command = new Command("the-command")
                 {
-                    new Option("-t")
-                    {
-                        Argument = new Argument
-                            {
-                                Arity = ArgumentArity.ExactlyOne,
-                                Suggestions = { "vegetable", "mineral", "animal" }
-                            }
-                    }
+                    new Option("-t", arity: ArgumentArity.ExactlyOne)
+                        .AddSuggestions("vegetable", "mineral", "animal")
                 };
 
             command.Parse("the-command -t m")
@@ -651,13 +586,8 @@ public void Option_argument_suggestions_can_be_provided_using_a_delegate()
         {
             var command = new Command("the-command")
             {
-                new Option<string>("-x") 
-                {
-                    Argument = new Argument<string>()
-                    {
-                        Suggestions = { (_, __) => new [] { "vegetable", "mineral", "animal" } }
-                    }
-                }
+                new Option<string>("-x")
+                    .AddSuggestions((_, __) => new [] { "vegetable", "mineral", "animal" })
             };
 
             var parseResult = command.Parse("the-command -x m");
@@ -673,27 +603,12 @@ public void When_caller_does_the_tokenizing_then_argument_suggestions_are_based_
         {
             var command = new Command("outer")
             {
-                new Option("one")
-                {
-                    Argument = new Argument
-                    {
-                        Arity = ArgumentArity.ExactlyOne
-                    }.FromAmong("one-a", "one-b", "one-c")
-                },
-                new Option("two")
-                {
-                    Argument = new Argument
-                    {
-                        Arity = ArgumentArity.ExactlyOne
-                    }.FromAmong("two-a", "two-b", "two-c")
-                },
-                new Option("three")
-                {
-                    Argument = new Argument
-                    {
-                        Arity = ArgumentArity.ExactlyOne
-                    }.FromAmong("three-a", "three-b", "three-c")
-                }
+                new Option("one", arity: ArgumentArity.ExactlyOne)
+                    .FromAmong("one-a", "one-b", "one-c"),
+                new Option("two", arity: ArgumentArity.ExactlyOne)
+                    .FromAmong("two-a", "two-b", "two-c"),
+                new Option("three", arity: ArgumentArity.ExactlyOne)
+                    .FromAmong("three-a", "three-b", "three-c")
             };
 
             var parser = new CommandLineBuilder()
@@ -712,27 +627,12 @@ public void When_caller_does_not_do_the_tokenizing_then_argument_suggestions_are
         {
             var command = new Command("outer")
             {
-                new Option("one")
-                {
-                    Argument = new Argument
-                    {
-                        Arity = ArgumentArity.ExactlyOne
-                    }.FromAmong("one-a", "one-b", "one-c")
-                },
-                new Option("two")
-                {
-                    Argument = new Argument
-                    {
-                        Arity = ArgumentArity.ExactlyOne
-                    }.FromAmong("two-a", "two-b", "two-c")
-                },
-                new Option("three")
-                {
-                    Argument = new Argument
-                    {
-                        Arity = ArgumentArity.ExactlyOne
-                    }.FromAmong("three-a", "three-b", "three-c")
-                }
+                new Option("one", arity: ArgumentArity.ExactlyOne)
+                    .FromAmong("one-a", "one-b", "one-c"),
+                new Option("two", arity: ArgumentArity.ExactlyOne)
+                    .FromAmong("two-a", "two-b", "two-c"),
+                new Option("three", arity: ArgumentArity.ExactlyOne)
+                    .FromAmong("three-a", "three-b", "three-c")
             };
 
             var result = command.Parse("outer two b");
@@ -831,14 +731,8 @@ public void Options_that_have_been_specified_to_their_maximum_arity_are_not_sugg
         {
             var command = new Command("command")
             {
-                new Option("--allows-one")
-                {
-                    Argument = new Argument<string>()
-                },
-                new Option("--allows-many")
-                {
-                    Argument = new Argument<string[]>()
-                }
+                new Option<string>("--allows-one"),
+                new Option<string[]>("--allows-many")
             };
 
             var commandLine = "--allows-one x";
@@ -851,14 +745,8 @@ public void Options_that_have_been_specified_to_their_maximum_arity_are_not_sugg
         public void When_current_symbol_is_an_option_that_requires_arguments_then_parent_symbol_suggestions_are_omitted()
         {
             var parser = new CommandLineBuilder()
-                         .AddOption(new Option("--allows-one")
-                         {
-                             Argument = new Argument<string>()
-                         })
-                         .AddOption(new Option("--allows-many")
-                         {
-                             Argument = new Argument<string[]>()
-                         })
+                         .AddOption(new Option<string>("--allows-one"))
+                         .AddOption(new Option<string[]>("--allows-many"))
                          .UseSuggestDirective()
                          .Build();
 
@@ -872,14 +760,8 @@ public void Option_substring_matching_when_arguments_have_default_values()
         {
             var command = new Command("the-command")
             {
-                new Option("--implicit")
-                {
-                    Argument = new Argument<string>(getDefaultValue: () => "the-default")
-                },
-                new Option("--not")
-                {
-                    Argument = new Argument<string>("the-default")
-                }
+                new Option<string>("--implicit", () => "the-default"),
+                new Option<string>("--not", () => "the-default")
             };
 
             var suggestions = command.Parse("m").GetSuggestions();
@@ -948,14 +830,8 @@ public void When_position_is_greater_than_input_length_in_a_string_command_line_
                 var command = new Command("the-command")
                 {
                     new Argument<string>(),
-                    new Option("--option1")
-                    {
-                        Argument = new Argument<string>().FromAmong("apple", "banana", "cherry", "durian")
-                    },
-                    new Option("--option2")
-                    {
-                        Argument = new Argument<string>()
-                    }
+                    new Option<string>("--option1").FromAmong("apple", "banana", "cherry", "durian"),
+                    new Option<string>("--option2")
                 };
 
                 var textToMatch = command.Parse("the-command --option1 a")
@@ -1047,14 +923,8 @@ public void When_position_is_unspecified_in_array_command_line_and_final_token_m
             {
                 var command = new Command("the-command")
                 {
-                    new Option("--option1")
-                    {
-                        Argument = new Argument<string>().FromAmong("apple", "banana", "cherry", "durian")
-                    },
-                    new Option("--option2")
-                    {
-                        Argument = new Argument<string>()
-                    },
+                    new Option<string>("--option1").FromAmong("apple", "banana", "cherry", "durian"),
+                    new Option<string>("--option2"),
                     new Argument<string>()
                 };
 
diff --git a/src/System.CommandLine.Tests/SymbolResultTests.cs b/src/System.CommandLine.Tests/SymbolResultTests.cs
index e8a0259c5..fc3a54a10 100644
--- a/src/System.CommandLine.Tests/SymbolResultTests.cs
+++ b/src/System.CommandLine.Tests/SymbolResultTests.cs
@@ -12,10 +12,7 @@ public class SymbolResultTests
         [Fact]
         public void An_option_with_a_default_value_and_no_explicitly_provided_argument_has_an_empty_arguments_property()
         {
-            var option = new Option("-x")
-            {
-                Argument = new Argument<string>("default")
-            };
+            var option = new Option<string>("-x", () => "default");
 
             var result = new RootCommand
             {
@@ -44,10 +41,7 @@ public void HasOption_can_be_used_to_check_the_presence_of_an_implicit_option()
         {
             var command = new Command("the-command")
             {
-                new Option(new[] { "-c", "--count" })
-                {
-                    Argument = new Argument<int>(() => 5)
-                }
+                new Option<int>(new[] { "-c", "--count" }, () => 5)
             };
 
             var result = command.Parse("the-command");
diff --git a/src/System.CommandLine/Argument.cs b/src/System.CommandLine/Argument.cs
index 4b74c52a5..deadaf161 100644
--- a/src/System.CommandLine/Argument.cs
+++ b/src/System.CommandLine/Argument.cs
@@ -5,6 +5,7 @@
 using System.CommandLine.Binding;
 using System.CommandLine.Parsing;
 using System.CommandLine.Suggestions;
+using System.Diagnostics.CodeAnalysis;
 using System.Linq;
 
 namespace System.CommandLine
@@ -44,7 +45,8 @@ public Argument(string name)
         /// <summary>
         /// Gets or sets the arity of the argument.
         /// </summary>
-        public IArgumentArity Arity
+        [NotNull]
+        public IArgumentArity? Arity
         {
             get
             {
diff --git a/src/System.CommandLine/Help/HelpOption.cs b/src/System.CommandLine/Help/HelpOption.cs
index 4218f2541..62ea2899f 100644
--- a/src/System.CommandLine/Help/HelpOption.cs
+++ b/src/System.CommandLine/Help/HelpOption.cs
@@ -16,10 +16,10 @@ internal class HelpOption : Option
         {
         }
 
-        public override Argument Argument
+        internal override Argument Argument
         {
             get => Argument.None;
-            set => throw new NotSupportedException();
+            set { }
         }
 
         protected bool Equals(HelpOption other)
diff --git a/src/System.CommandLine/Option.cs b/src/System.CommandLine/Option.cs
index d6ead081c..d011a33a6 100644
--- a/src/System.CommandLine/Option.cs
+++ b/src/System.CommandLine/Option.cs
@@ -15,12 +15,29 @@ public class Option :
         private string? _implicitName;
         private protected readonly HashSet<string> _unprefixedAliases = new HashSet<string>();
 
-        public Option(string alias, string? description = null)
-            : this(new[] { alias }, description)
-        {
-        }
-
-        public Option(string[] aliases, string? description = null) : base(description)
+        public Option(
+            string alias,
+            string? description = null,
+            Type? argumentType = null,
+            Func<object?>? getDefaultValue = null,
+            IArgumentArity? arity = null)
+            : this(new[] { alias }, description, argumentType, getDefaultValue, arity)
+        { }
+
+        public Option(
+            string[] aliases,
+            string? description = null,
+            Type? argumentType = null,
+            Func<object?>? getDefaultValue = null,
+            IArgumentArity? arity = null)
+            : this(aliases, description, GetArgument(argumentType, getDefaultValue, arity))
+        { }
+
+        internal Option(
+            string[] aliases,
+            string? description,
+            Argument? argument)
+            : base(description)
         {
             if (aliases is null)
             {
@@ -37,13 +54,42 @@ public Option(string[] aliases, string? description = null) : base(description)
                 var alias = aliases[i];
                 AddAlias(alias);
             }
+            if (argument != null)
+            {
+                Argument = argument;
+            }
         }
 
-        public virtual Argument Argument
+        private static Argument? GetArgument(Type? argumentType, Func<object?>? getDefaultValue, IArgumentArity? arity)
         {
-            get => Children.Arguments.Count > 0
-                       ? Children.Arguments[0]
-                       : Argument.None;
+            if (argumentType is null &&
+                getDefaultValue is null &&
+                arity is null)
+            {
+                return null;
+            }
+
+            var rv = new Argument();
+            if (argumentType != null)
+            {
+                rv.ArgumentType = argumentType;
+            }
+            if (getDefaultValue != null)
+            {
+                rv.SetDefaultValueFactory(getDefaultValue);
+            }
+            if (arity != null)
+            {
+                rv.Arity = arity;
+            }
+            return rv;
+        }
+
+        private protected virtual Argument GetDefaultArgument() => Argument.None;
+
+        internal virtual Argument Argument
+        {
+            get => Arguments.FirstOrDefault() ?? Argument.None;
             set
             {
                 for (var i = 0; i < Children.Arguments.Count; i++)
@@ -55,6 +101,29 @@ public virtual Argument Argument
             }
         }
 
+        //TODO: Guard against Argument.None?
+        public string ArgumentName
+        {
+            get => Argument.Name;
+            set => Argument.Name = value;
+        }
+
+        public string? ArgumentDescription
+        {
+            get => Argument.Description;
+            set => Argument.Description = value;
+        }
+
+        public bool ArgumentIsHidden
+        {
+            get => Argument.IsHidden;
+            set => Argument.IsHidden = value;
+        }
+
+        public Type ArgumentType => Argument.ArgumentType;
+
+        private IEnumerable<Argument> Arguments => Children.OfType<Argument>();
+
         public override string Name
         {
             get => base.Name;
diff --git a/src/System.CommandLine/Option{T}.cs b/src/System.CommandLine/Option{T}.cs
index 208d9a2ec..948111100 100644
--- a/src/System.CommandLine/Option{T}.cs
+++ b/src/System.CommandLine/Option{T}.cs
@@ -8,79 +8,62 @@ namespace System.CommandLine
     public class Option<T> : Option
     {
         public Option(
-            string alias, 
-            string? description = null) : base(alias, description)
-        {
-            Argument = new Argument<T>();
-        }
+            string alias,
+            string? description = null,
+            IArgumentArity? arity = null) 
+            : base(new[] { alias }, description, new Argument<T> { Arity = arity })
+        { }
 
         public Option(
-            string[] aliases, 
-            string? description = null) : base(aliases, description)
-        {
-            Argument = new Argument<T>();
-        }
+            string[] aliases,
+            string? description = null) 
+            : base(aliases, description, new Argument<T>())
+        { }
 
         public Option(
             string alias,
             ParseArgument<T> parseArgument,
             bool isDefault = false,
-            string? description = null) : base(alias, description)
-        {
-            if (parseArgument is null)
-            {
-                throw new ArgumentNullException(nameof(parseArgument));
-            }
-
-            Argument = new Argument<T>(parseArgument, isDefault);
-        }
+            string? description = null) 
+            : base(new[] { alias }, description, 
+                  new Argument<T>(parseArgument ?? throw new ArgumentNullException(nameof(parseArgument)), isDefault))
+        { }
 
         public Option(
             string[] aliases,
             ParseArgument<T> parseArgument,
             bool isDefault = false,
-            string? description = null) : base(aliases, description)
-        {
-            if (parseArgument is null)
-            {
-                throw new ArgumentNullException(nameof(parseArgument));
-            }
-
-            Argument = new Argument<T>(parseArgument, isDefault);
-        }
+            string? description = null) 
+            : base(aliases, description, new Argument<T>(parseArgument ?? throw new ArgumentNullException(nameof(parseArgument)), isDefault))
+        { }
 
         public Option(
             string alias,
             Func<T> getDefaultValue,
-            string? description = null) : base(alias, description)
-        {
-            if (getDefaultValue is null)
-            {
-                throw new ArgumentNullException(nameof(getDefaultValue));
-            }
-
-            Argument = new Argument<T>(getDefaultValue);
-        }
+            string? description = null) 
+            : base(new[] { alias }, description, 
+                  new Argument<T>(getDefaultValue ?? throw new ArgumentNullException(nameof(getDefaultValue))))
+        { }
 
         public Option(
             string[] aliases,
             Func<T> getDefaultValue,
-            string? description = null) : base(aliases, description)
-        {
-            if (getDefaultValue is null)
-            {
-                throw new ArgumentNullException(nameof(getDefaultValue));
-            }
+            string? description = null) 
+            : base(aliases, description, new Argument<T>(getDefaultValue ?? throw new ArgumentNullException(nameof(getDefaultValue))))
+        { }
 
-            Argument = new Argument<T>(getDefaultValue);
+        private protected override Argument GetDefaultArgument()
+        {
+            return new Argument<T> { Arity = ArgumentArity.Zero };
         }
 
-        public override Argument Argument
+        internal override Argument Argument
         {
             set
             {
                 if (!(value is Argument<T>))
                 {
+
                     throw new ArgumentException($"{nameof(Argument)} must be of type {typeof(Argument<T>)} but was {value?.GetType().ToString() ?? "null"}");
                 }