dotnet · jonsequitur · Dec 18, 2021 · Dec 18, 2021 · Dec 18, 2021
diff --git a/...ty.Tests/ApiCompatibilityApprovalTests.System_CommandLine_api_is_not_changed.approved.txt b/...ty.Tests/ApiCompatibilityApprovalTests.System_CommandLine_api_is_not_changed.approved.txt
diff --git a/src/System.CommandLine.Benchmarks/CommandLine/Perf_Parser_NestedCommands.cs b/src/System.CommandLine.Benchmarks/CommandLine/Perf_Parser_NestedCommands.cs
@@ -55,7 +55,7 @@ public void SetupRootCommand()
             GenerateTestNestedCommands(rootCommand, TestCommandsDepth, TestCommandsDepth);
 
             // Choose only one path from the commands tree for the test arguments string
-            ISymbol currentCmd = rootCommand;
+            Symbol currentCmd = rootCommand;
             while (currentCmd.Children.Count > 0)
             {
                 currentCmd = currentCmd.Children[0];

diff --git a/src/System.CommandLine.Generator.CommandHandler/CommandExtensions.cs b/src/System.CommandLine.Generator.CommandHandler/CommandExtensions.cs
@@ -18,7 +18,7 @@ public static class CommandExtensions
     public static void SetHandler<TDelegate>(
         this Command command,
         TDelegate @delegate,
-        params ISymbol[] symbols)
+        params Symbol[] symbols)
     {
         throw new InvalidOperationException(_messageForWhenGeneratorIsNotInUse);
     }

diff --git a/src/System.CommandLine.NamingConventionBinder/ModelBinder.cs b/src/System.CommandLine.NamingConventionBinder/ModelBinder.cs
@@ -135,7 +135,7 @@ private bool ShortCutTheBinding()
                                                    bindingContext.ParseResult.CommandResult.LocalizationResources,
                                                    out var boundValue)
                    ? (true, boundValue?.Value, true)
-                   : (false,(object?) null, false);
+                   : (false, null, false);
     }
 
     private (bool success, object? newInstance, bool anyNonDefaults) InstanceFromSpecificConstructor(

diff --git a/src/System.CommandLine.NamingConventionBinder/SpecificSymbolValueSource.cs b/src/System.CommandLine.NamingConventionBinder/SpecificSymbolValueSource.cs
@@ -21,15 +21,15 @@ public bool TryGetValue(IValueDescriptor valueDescriptor,
         var specificDescriptor = ValueDescriptor;
         switch (specificDescriptor)
         {
-            case IOption option:
+            case Option option:
                 var optionResult = bindingContext?.ParseResult.FindResultFor(option);
                 if (optionResult is not null)
                 {
                     boundValue = optionResult.GetValueOrDefault();
                     return true;
                 }
                 break;
-            case IArgument argument:
+            case Argument argument:
                 var argumentResult = bindingContext?.ParseResult.FindResultFor(argument);
                 if (argumentResult is not null)
                 {

diff --git a/src/System.CommandLine.Tests/CommandTests.cs b/src/System.CommandLine.Tests/CommandTests.cs
@@ -215,7 +215,7 @@ public void Commands_can_have_aliases()
 
             var result = command.Parse("that");
 
-            result.CommandResult.Command.Should().Be(command);
+            result.CommandResult.Command.Should().BeSameAs(command);
             result.Errors.Should().BeEmpty();
         }
 
@@ -229,7 +229,7 @@ public void RootCommand_can_have_aliases()
 
             var result = command.Parse("that");
 
-            result.CommandResult.Command.Should().Be(command);
+            result.CommandResult.Command.Should().BeSameAs(command);
             result.Errors.Should().BeEmpty();
         }
 
@@ -246,7 +246,7 @@ public void Subcommands_can_have_aliases()
 
             var result = rootCommand.Parse("that");
 
-            result.CommandResult.Command.Should().Be(subcommand);
+            result.CommandResult.Command.Should().BeSameAs(subcommand);
             result.Errors.Should().BeEmpty();
         }
 

diff --git a/src/System.CommandLine.Tests/Help/HelpBuilderExtensions.cs b/src/System.CommandLine.Tests/Help/HelpBuilderExtensions.cs
@@ -10,7 +10,7 @@ public static class HelpBuilderExtensions
     {
         public static void Write(
             this HelpBuilder builder,
-            ICommand command,
+            Command command,
             TextWriter writer) =>
             builder.Write(new HelpContext(builder, command, writer));
     }

diff --git a/src/System.CommandLine.Tests/ParserTests.cs b/src/System.CommandLine.Tests/ParserTests.cs
@@ -838,8 +838,8 @@ public void A_renamed_RootCommand_can_be_omitted_from_the_parsed_args()
             var result2 = rootCommand.Parse("outer inner -x hello");
             var result3 = rootCommand.Parse($"{RootCommand.ExecutableName} inner -x hello");
 
-            result2.RootCommandResult.Command.Should().Be(result1.RootCommandResult.Command);
-            result3.RootCommandResult.Command.Should().Be(result1.RootCommandResult.Command);
+            result2.RootCommandResult.Command.Should().BeSameAs(result1.RootCommandResult.Command);
+            result3.RootCommandResult.Command.Should().BeSameAs(result1.RootCommandResult.Command);
         }
 
         [Fact]
@@ -1069,19 +1069,19 @@ public void Option_and_Command_can_have_the_same_alias()
                   .CommandResult
                   .Command
                   .Should()
-                  .Be(innerCommand);
+                  .BeSameAs(innerCommand);
 
             parser.Parse("outer --inner")
                   .CommandResult
                   .Command
                   .Should()
-                  .Be(outerCommand);
+                  .BeSameAs(outerCommand);
 
             parser.Parse("outer --inner inner")
                   .CommandResult
                   .Command
                   .Should()
-                  .Be(innerCommand);
+                  .BeSameAs(innerCommand);
 
             parser.Parse("outer --inner inner")
                   .CommandResult
@@ -1218,7 +1218,7 @@ public void Option_arguments_can_match_subcommands()
             _output.WriteLine(result.ToString());
 
             result.GetValueForOption(optionA).Should().Be("subcommand");
-            result.CommandResult.Command.Should().Be(root);
+            result.CommandResult.Command.Should().BeSameAs(root);
         }
 
         [Fact]
@@ -1236,7 +1236,7 @@ public void Arguments_can_match_subcommands()
 
             var result = root.Parse("subcommand one two three subcommand four");
 
-            result.CommandResult.Command.Should().Be(subcommand);
+            result.CommandResult.Command.Should().BeSameAs(subcommand);
 
             result.GetValueForArgument(argument)
                   .Should()
@@ -1681,7 +1681,7 @@ public void Empty_strings_in_parsed_args_array_are_ignored()
 
             result.Errors.Should().BeEmpty();
 
-            result.CommandResult.Command.Should().Be(subcommand);
+            result.CommandResult.Command.Should().BeSameAs(subcommand);
             result.FindResultFor(option).Should().NotBeNull();
         }
 

diff --git a/src/System.CommandLine.Tests/ParsingValidationTests.cs b/src/System.CommandLine.Tests/ParsingValidationTests.cs
@@ -915,7 +915,7 @@ public void A_command_with_subcommands_is_valid_to_invoke_if_it_has_a_handler()
             var result = outer.Parse("outer inner");
 
             result.Errors.Should().BeEmpty();
-            result.CommandResult.Command.Should().Be(inner);
+            result.CommandResult.Command.Should().BeSameAs(inner);
         }
 
         [Fact]

diff --git a/src/System.CommandLine.Tests/SymbolSetExtensions.cs b/src/System.CommandLine.Tests/SymbolSetExtensions.cs
@@ -8,7 +8,7 @@ namespace System.CommandLine.Tests
 {
     internal static class SymbolSetExtensions
     {
-        internal static ISymbol GetByAlias(this SymbolSet symbolSet, string alias)
+        internal static Symbol GetByAlias(this SymbolSet symbolSet, string alias)
             => symbolSet.SingleOrDefault(symbol => symbol.Name.Equals(alias) || symbol is IdentifierSymbol id && id.HasAlias(alias));
 
         internal static bool ContainsAlias(this SymbolSet symbolSet, string alias)

diff --git a/src/System.CommandLine/Argument.cs b/src/System.CommandLine/Argument.cs
@@ -5,13 +5,14 @@
 using System.CommandLine.Binding;
 using System.CommandLine.Parsing;
 using System.CommandLine.Completions;
-using System.Diagnostics.CodeAnalysis;
 using System.Linq;
 
 namespace System.CommandLine
 {
-    /// <inheritdoc cref="IArgument"/>
-    public class Argument : Symbol, IArgument
+    /// <summary>
+    /// A symbol defining a value that can be passed on the command line to a <see cref="Command">command</see> or <see cref="Option">option</see>.
+    /// </summary>
+    public class Argument : Symbol, IValueDescriptor
     {
         private Func<ArgumentResult, object?>? _defaultValueFactory;
         private ArgumentArity _arity;
@@ -204,9 +205,6 @@ public override IEnumerable<CompletionItem> GetCompletions(CompletionContext con
         /// <inheritdoc />
         public override string ToString() => $"{nameof(Argument)}: {Name}";
 
-        /// <inheritdoc />
-        ArgumentArity IArgument.Arity => Arity;
-
         /// <inheritdoc />
         string IValueDescriptor.ValueName => Name;
     }

diff --git a/src/System.CommandLine/ArgumentArity.cs b/src/System.CommandLine/ArgumentArity.cs
@@ -49,12 +49,12 @@ public ArgumentArity(int minimumNumberOfValues, int maximumNumberOfValues)
         }
 
         /// <summary>
-        /// Gets the minimum number of values required for an <see cref="IArgument">argument</see>.
+        /// Gets the minimum number of values required for an <see cref="Argument">argument</see>.
         /// </summary>
         public int MinimumNumberOfValues { get; }
 
         /// <summary>
-        /// Gets the maximum number of values allowed for an <see cref="IArgument">argument</see>.
+        /// Gets the maximum number of values allowed for an <see cref="Argument">argument</see>.
         /// </summary>
         public int MaximumNumberOfValues { get; }
 
@@ -72,7 +72,7 @@ public override int GetHashCode()
 
         internal static FailedArgumentConversionArityResult? Validate(
             SymbolResult symbolResult,
-            IArgument argument,
+            Argument argument,
             int minimumNumberOfValues,
             int maximumNumberOfValues)
         {
@@ -148,12 +148,12 @@ internal static ArgumentArity Default(Type type, Argument argument, ParentNode?
 
             if (type != typeof(string) && typeof(IEnumerable).IsAssignableFrom(type))
             {
-                return parent is ICommand
+                return parent is Command
                            ? ZeroOrMore
                            : OneOrMore;
             }
 
-            if (parent is ICommand &&
+            if (parent is Command &&
                 (argument.HasDefaultValue ||
                  type.IsNullable()))
             {

diff --git a/src/System.CommandLine/Binding/ArgumentConversionResult.cs b/src/System.CommandLine/Binding/ArgumentConversionResult.cs
@@ -5,19 +5,19 @@ namespace System.CommandLine.Binding
 {
     internal abstract class ArgumentConversionResult
     {
-        private protected ArgumentConversionResult(IArgument argument)
+        private protected ArgumentConversionResult(Argument argument)
         {
             Argument = argument ?? throw new ArgumentNullException(nameof(argument));
         }
 
-        public IArgument Argument { get; }
+        public Argument Argument { get; }
 
         internal string? ErrorMessage { get; set; }
 
-        internal static FailedArgumentConversionResult Failure(IArgument argument, string error) => new(argument, error);
+        internal static FailedArgumentConversionResult Failure(Argument argument, string error) => new(argument, error);
 
-        public static SuccessfulArgumentConversionResult Success(IArgument argument, object? value) => new(argument, value);
+        public static SuccessfulArgumentConversionResult Success(Argument argument, object? value) => new(argument, value);
 
-        internal static NoArgumentConversionResult None(IArgument argument) => new(argument);
+        internal static NoArgumentConversionResult None(Argument argument) => new(argument);
     }
 }
diff --git a/src/System.CommandLine/Binding/ArgumentConverter.cs b/src/System.CommandLine/Binding/ArgumentConverter.cs
@@ -110,7 +110,7 @@ internal static class ArgumentConverter
         private delegate bool TryConvertString(string token, out object? value);
 
         internal static ArgumentConversionResult ConvertObject(
-            IArgument argument,
+            Argument argument,
             Type type,
             object? value,
             LocalizationResources localizationResources)
@@ -135,7 +135,7 @@ internal static ArgumentConversionResult ConvertObject(
         }
 
         private static ArgumentConversionResult ConvertString(
-            IArgument argument,
+            Argument argument,
             Type type,
             string value,
             LocalizationResources localizationResources)
@@ -184,7 +184,7 @@ private static ArgumentConversionResult ConvertString(
         }
 
         public static ArgumentConversionResult ConvertStrings(
-            IArgument argument,
+            Argument argument,
             Type type,
             IReadOnlyList<string> tokens,
             LocalizationResources localizationResources,
@@ -354,7 +354,7 @@ private static bool HasStringTypeConverter(this Type type) =>
             typeConverter.CanConvertFrom(typeof(string));
 
         private static FailedArgumentConversionResult Failure(
-            IArgument argument,
+            Argument argument,
             Type expectedType,
             string value,
             LocalizationResources localizationResources)

diff --git a/src/System.CommandLine/Binding/BindingContext.cs b/src/System.CommandLine/Binding/BindingContext.cs
@@ -119,7 +119,7 @@ internal bool TryBindToScalarValue(
                 else
                 {
                     var parsed = ArgumentConverter.ConvertObject(
-                        valueDescriptor as IArgument ?? new Argument(valueDescriptor.ValueName),
+                        valueDescriptor as Argument ?? new Argument(valueDescriptor.ValueName),
                         valueDescriptor.ValueType,
                         value,
                         localizationResources);

diff --git a/src/System.CommandLine/Binding/FailedArgumentConversionArityResult.cs b/src/System.CommandLine/Binding/FailedArgumentConversionArityResult.cs
@@ -5,7 +5,7 @@ namespace System.CommandLine.Binding
 {
     internal abstract class FailedArgumentConversionArityResult : FailedArgumentConversionResult
     {
-        internal FailedArgumentConversionArityResult(IArgument argument, string errorMessage) : base(argument, errorMessage)
+        internal FailedArgumentConversionArityResult(Argument argument, string errorMessage) : base(argument, errorMessage)
         {
         }
     }

diff --git a/src/System.CommandLine/Binding/FailedArgumentConversionResult.cs b/src/System.CommandLine/Binding/FailedArgumentConversionResult.cs
@@ -6,7 +6,7 @@ namespace System.CommandLine.Binding
     internal class FailedArgumentConversionResult : ArgumentConversionResult
     {
         internal FailedArgumentConversionResult(
-            IArgument argument, 
+            Argument argument, 
             string errorMessage) : base(argument)
         {
             if (string.IsNullOrWhiteSpace(errorMessage))

diff --git a/src/System.CommandLine/Binding/FailedArgumentTypeConversionResult.cs b/src/System.CommandLine/Binding/FailedArgumentTypeConversionResult.cs
@@ -8,7 +8,7 @@ namespace System.CommandLine.Binding
     internal class FailedArgumentTypeConversionResult : FailedArgumentConversionResult
     {
         internal FailedArgumentTypeConversionResult(
-            IArgument argument,
+            Argument argument,
             Type expectedType,
             string value,
             LocalizationResources localizationResources) :
@@ -17,22 +17,22 @@ internal FailedArgumentTypeConversionResult(
         }
 
         private static string FormatErrorMessage(
-            IArgument argument,
+            Argument argument,
             Type expectedType,
             string value,
             LocalizationResources localizationResources)
         {
             if (argument is Argument a &&
                 a.FirstParent is not null && a.FirstParent.Next is null)
             {
-                var firstParent = (IIdentifierSymbol) a.FirstParent.Symbol;
+                var firstParent = (IdentifierSymbol) a.FirstParent.Symbol;
                 var alias = firstParent.Aliases.First();
 
                 switch(firstParent)
                 {
-                    case ICommand _:
+                    case Command _:
                         return localizationResources.ArgumentConversionCannotParseForCommand(value, alias, expectedType);
-                    case IOption _:
+                    case Option _:
                         return localizationResources.ArgumentConversionCannotParseForOption(value, alias, expectedType);
                 }
             }

diff --git a/src/System.CommandLine/Binding/MissingArgumentConversionResult.cs b/src/System.CommandLine/Binding/MissingArgumentConversionResult.cs
@@ -5,7 +5,7 @@ namespace System.CommandLine.Binding
 {
     internal class MissingArgumentConversionResult : FailedArgumentConversionArityResult
     {
-        internal MissingArgumentConversionResult(IArgument argument, string errorMessage) : base(argument, errorMessage)
+        internal MissingArgumentConversionResult(Argument argument, string errorMessage) : base(argument, errorMessage)
         {
         }
     }

diff --git a/src/System.CommandLine/Binding/NoArgumentConversionResult.cs b/src/System.CommandLine/Binding/NoArgumentConversionResult.cs
@@ -5,7 +5,7 @@ namespace System.CommandLine.Binding
 {
     internal class NoArgumentConversionResult : ArgumentConversionResult
     {
-        internal NoArgumentConversionResult(IArgument argument) : base(argument)
+        internal NoArgumentConversionResult(Argument argument) : base(argument)
         {
         }
     }

diff --git a/src/System.CommandLine/Binding/SuccessfulArgumentConversionResult.cs b/src/System.CommandLine/Binding/SuccessfulArgumentConversionResult.cs
@@ -6,7 +6,7 @@ namespace System.CommandLine.Binding
     internal class SuccessfulArgumentConversionResult : ArgumentConversionResult
     {
         internal SuccessfulArgumentConversionResult(
-            IArgument argument, 
+            Argument argument, 
             object? value) : base(argument)
         {
             Value = value;

diff --git a/src/System.CommandLine/Binding/TooManyArgumentsConversionResult.cs b/src/System.CommandLine/Binding/TooManyArgumentsConversionResult.cs
@@ -5,7 +5,7 @@ namespace System.CommandLine.Binding
 {
     internal class TooManyArgumentsConversionResult : FailedArgumentConversionArityResult
     {
-        internal TooManyArgumentsConversionResult(IArgument argument, string errorMessage) : base(argument, errorMessage)
+        internal TooManyArgumentsConversionResult(Argument argument, string errorMessage) : base(argument, errorMessage)
         {
         }
     }

diff --git a/src/System.CommandLine/Builder/CommandLineBuilderExtensions.cs b/src/System.CommandLine/Builder/CommandLineBuilderExtensions.cs
@@ -772,7 +772,7 @@ public static CommandLineBuilder UseVersionOption(
 
         private static bool ShowHelp(
             InvocationContext context,
-            IOption helpOption)
+            Option helpOption)
         {
             if (context.ParseResult.FindResultFor(helpOption) is { })
             {
-Original file line number
+Diff line change
@@ Expand Up / @@ -5,7 +5,7 @@ namespace System.CommandLine.Binding @@
     {
         internal abstract class FailedArgumentConversionArityResult : FailedArgumentConversionResult
         {
-            internal FailedArgumentConversionArityResult(IArgument argument, string errorMessage) : base(argument, errorMessage)
+            internal FailedArgumentConversionArityResult(Argument argument, string errorMessage) : base(argument, errorMessage)
             {
             }
         }
@@ Expand Down @@