Improve tests

CliFx.Analyzers/CommandSchemaAnalyzer.cs

@@ -275,11 +275,8 @@ namespace CliFx.Analyzers
         private static void CheckCommandType(SymbolAnalysisContext context)
         {
             // Named type: MyCommand
-            if (!(context.Symbol is INamedTypeSymbol namedTypeSymbol))
-                return;
-
-            // Only classes
-            if (namedTypeSymbol.TypeKind != TypeKind.Class)
+            if (!(context.Symbol is INamedTypeSymbol namedTypeSymbol) ||
+                namedTypeSymbol.TypeKind != TypeKind.Class)
                 return;
 
             // Implements ICommand?

CliFx.Tests/ArgumentConversionSpecs.cs

@@ -913,7 +913,7 @@ namespace CliFx.Tests
         }
 
         [Fact]
-        public async Task Argument_value_can_be_bound_to_an_enum_type_by_name()
+        public async Task Argument_value_can_be_bound_to_enum_type_by_name()
         {
             // Arrange
             var (console, stdOut, _) = VirtualConsole.CreateBuffered();
@@ -941,7 +941,7 @@ namespace CliFx.Tests
         }
 
         [Fact]
-        public async Task Argument_value_can_be_bound_to_an_enum_type_by_id()
+        public async Task Argument_value_can_be_bound_to_enum_type_by_id()
         {
             // Arrange
             var (console, stdOut, _) = VirtualConsole.CreateBuffered();
@@ -1318,6 +1318,54 @@ namespace CliFx.Tests
             });
         }
 
+        [Fact]
+        public async Task Argument_value_can_only_be_bound_if_the_target_type_is_supported()
+        {
+            // Arrange
+            var (console, _, stdErr) = VirtualConsole.CreateBuffered();
+
+            var application = new CliApplicationBuilder()
+                .AddCommand<UnsupportedArgumentTypesCommand>()
+                .UseConsole(console)
+                .Build();
+
+            // Act
+            var exitCode = await application.RunAsync(new[]
+            {
+                "cmd", "--custom"
+            });
+
+            // Assert
+            exitCode.Should().NotBe(0);
+            stdErr.GetString().Should().NotBeNullOrWhiteSpace();
+
+            _output.WriteLine(stdErr.GetString());
+        }
+
+        [Fact]
+        public async Task Argument_value_can_only_be_bound_if_the_provided_value_can_be_converted_to_the_target_type()
+        {
+            // Arrange
+            var (console, _, stdErr) = VirtualConsole.CreateBuffered();
+
+            var application = new CliApplicationBuilder()
+                .AddCommand<SupportedArgumentTypesCommand>()
+                .UseConsole(console)
+                .Build();
+
+            // Act
+            var exitCode = await application.RunAsync(new[]
+            {
+                "cmd", "--int", "foo"
+            });
+
+            // Assert
+            exitCode.Should().NotBe(0);
+            stdErr.GetString().Should().NotBeNullOrWhiteSpace();
+
+            _output.WriteLine(stdErr.GetString());
+        }
+
         [Fact]
         public async Task Argument_value_can_only_be_bound_to_non_nullable_type_if_it_is_set()
         {
@@ -1365,5 +1413,29 @@ namespace CliFx.Tests
 
             _output.WriteLine(stdErr.GetString());
         }
+
+        [Fact]
+        public async Task Argument_values_can_only_be_bound_to_a_type_that_implements_IEnumerable_and_can_be_converted_from_an_array()
+        {
+            // Arrange
+            var (console, _, stdErr) = VirtualConsole.CreateBuffered();
+
+            var application = new CliApplicationBuilder()
+                .AddCommand<UnsupportedArgumentTypesCommand>()
+                .UseConsole(console)
+                .Build();
+
+            // Act
+            var exitCode = await application.RunAsync(new[]
+            {
+                "cmd", "--custom-enumerable"
+            });
+
+            // Assert
+            exitCode.Should().NotBe(0);
+            stdErr.GetString().Should().NotBeNullOrWhiteSpace();
+
+            _output.WriteLine(stdErr.GetString());
+        }
     }
 }

CliFx.Tests/Commands/UnsupportedArgumentTypesCommand.cs

@@ -8,11 +8,11 @@ namespace CliFx.Tests.Commands
     [Command("cmd")]
     public partial class UnsupportedArgumentTypesCommand : SelfSerializeCommandBase
     {
-        [CommandOption("str-non-initializable")]
-        public CustomType? StringNonInitializable { get; set; }
+        [CommandOption("custom")]
+        public CustomType? CustomNonConvertible { get; set; }
 
-        [CommandOption("str-enumerable-non-initializable")]
-        public CustomEnumerable<string>? StringEnumerableNonInitializable { get; set; }
+        [CommandOption("custom-enumerable")]
+        public CustomEnumerable<string>? CustomEnumerableNonConvertible { get; set; }
     }
 
     public partial class UnsupportedArgumentTypesCommand

CliFx/CliApplicationBuilder.cs

@@ -165,9 +165,9 @@ namespace CliFx
         /// </summary>
         public CliApplication Build()
         {
-            _title ??= TryGetDefaultTitle() ?? "App";
-            _executableName ??= TryGetDefaultExecutableName() ?? "app";
-            _versionText ??= TryGetDefaultVersionText() ?? "v1.0";
+            _title ??= GetDefaultTitle();
+            _executableName ??= GetDefaultExecutableName();
+            _versionText ??= GetDefaultVersionText();
             _console ??= new SystemConsole();
             _typeActivator ??= new DefaultTypeActivator();
 
@@ -185,23 +185,29 @@ namespace CliFx
         // Entry assembly is null in tests
         private static Assembly? EntryAssembly => LazyEntryAssembly.Value;
 
-        private static string? TryGetDefaultTitle() => EntryAssembly?.GetName().Name;
+        private static string GetDefaultTitle() => EntryAssembly?.GetName().Name?? "App";
 
-        private static string? TryGetDefaultExecutableName()
+        private static string GetDefaultExecutableName()
         {
             var entryAssemblyLocation = EntryAssembly?.Location;
 
             // The assembly can be an executable or a dll, depending on how it was packaged
-            var isDll = string.Equals(Path.GetExtension(entryAssemblyLocation), ".dll", StringComparison.OrdinalIgnoreCase);
+            var isDll = string.Equals(
+                Path.GetExtension(entryAssemblyLocation),
+                ".dll",
+                StringComparison.OrdinalIgnoreCase
+            );
 
-            return isDll
+            var name = isDll
                 ? "dotnet " + Path.GetFileName(entryAssemblyLocation)
                 : Path.GetFileNameWithoutExtension(entryAssemblyLocation);
+
+            return name ?? "app";
         }
 
-        private static string? TryGetDefaultVersionText() =>
+        private static string GetDefaultVersionText() =>
             EntryAssembly != null
                 ? $"v{EntryAssembly.GetName().Version.ToSemanticString()}"
-                : null;
+                : "v1.0";
     }
 }

CliFx/DefaultTypeActivator.cs

@@ -1,5 +1,6 @@
 using System;
 using CliFx.Exceptions;
+using CliFx.Internal.Extensions;
 
 namespace CliFx
 {
@@ -13,7 +14,7 @@ namespace CliFx
         {
             try
             {
-                return Activator.CreateInstance(type);
+                return type.CreateInstance();
             }
             catch (Exception ex)
             {

CliFx/Internal/Extensions/TypeExtensions.cs

@@ -8,7 +8,9 @@ namespace CliFx.Internal.Extensions
 {
     internal static class TypeExtensions
     {
-        public static T CreateInstance<T>(this Type type) => (T) Activator.CreateInstance(type);
+        public static object CreateInstance(this Type type) => Activator.CreateInstance(type);
+
+        public static T CreateInstance<T>(this Type type) => (T) type.CreateInstance();
 
         public static bool Implements(this Type type, Type interfaceType) => type.GetInterfaces().Contains(interfaceType);