Use latest C# features

CliFx.Analyzers.Tests/CliFx.Analyzers.Tests.csproj

@@ -9,7 +9,7 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="Basic.Reference.Assemblies.Net70" Version="1.4.5" />
+    <PackageReference Include="Basic.Reference.Assemblies.Net80" Version="1.4.5" />
     <PackageReference Include="coverlet.collector" Version="6.0.0" PrivateAssets="all" />
     <PackageReference Include="CSharpier.MsBuild" Version="0.26.5" PrivateAssets="all" />
     <PackageReference Include="GitHubActionsTestLogger" Version="2.3.3" PrivateAssets="all" />

CliFx.Analyzers.Tests/OptionMustHaveValidValidatorsAnalyzerSpecs.cs

@@ -23,7 +23,7 @@ public class OptionMustHaveValidValidatorsAnalyzerSpecs
             [Command]
             public class MyCommand : ICommand
             {
-                [CommandOption("foo", Validators = new[] {typeof(MyValidator)})]
+                [CommandOption("foo", Validators = new[] { typeof(MyValidator) })]
                 public string? Foo { get; init; }
             
                 public ValueTask ExecuteAsync(IConsole console) => default;
@@ -48,7 +48,7 @@ public class OptionMustHaveValidValidatorsAnalyzerSpecs
             [Command]
             public class MyCommand : ICommand
             {
-                [CommandOption("foo", Validators = new[] {typeof(MyValidator)})]
+                [CommandOption("foo", Validators = new[] { typeof(MyValidator) })]
                 public string? Foo { get; init; }
             
                 public ValueTask ExecuteAsync(IConsole console) => default;
@@ -73,7 +73,7 @@ public class OptionMustHaveValidValidatorsAnalyzerSpecs
             [Command]
             public class MyCommand : ICommand
             {
-                [CommandOption("foo", Validators = new[] {typeof(MyValidator)})]
+                [CommandOption("foo", Validators = new[] { typeof(MyValidator) })]
                 public string? Foo { get; init; }
             
                 public ValueTask ExecuteAsync(IConsole console) => default;

CliFx.Analyzers.Tests/ParameterMustHaveValidValidatorsAnalyzerSpecs.cs

@@ -23,7 +23,7 @@ public class ParameterMustHaveValidValidatorsAnalyzerSpecs
             [Command]
             public class MyCommand : ICommand
             {
-                [CommandParameter(0, Validators = new[] {typeof(MyValidator)})]
+                [CommandParameter(0, Validators = new[] { typeof(MyValidator) })]
                 public required string Foo { get; init; }
 
                 public ValueTask ExecuteAsync(IConsole console) => default;
@@ -48,7 +48,7 @@ public class ParameterMustHaveValidValidatorsAnalyzerSpecs
             [Command]
             public class MyCommand : ICommand
             {
-                [CommandParameter(0, Validators = new[] {typeof(MyValidator)})]
+                [CommandParameter(0, Validators = new[] { typeof(MyValidator) })]
                 public required string Foo { get; init; }
 
                 public ValueTask ExecuteAsync(IConsole console) => default;
@@ -73,7 +73,7 @@ public class ParameterMustHaveValidValidatorsAnalyzerSpecs
             [Command]
             public class MyCommand : ICommand
             {
-                [CommandParameter(0, Validators = new[] {typeof(MyValidator)})]
+                [CommandParameter(0, Validators = new[] { typeof(MyValidator) })]
                 public required string Foo { get; init; }
 
                 public ValueTask ExecuteAsync(IConsole console) => default;

CliFx.Analyzers.Tests/Utils/AnalyzerAssertions.cs

@@ -47,14 +47,14 @@ internal class AnalyzerAssertions(DiagnosticAnalyzer analyzer)
         // Parse the source code
         var ast = SyntaxFactory.ParseSyntaxTree(
             SourceText.From(sourceCodeWithUsings),
-            CSharpParseOptions.Default
+            CSharpParseOptions.Default.WithLanguageVersion(LanguageVersion.Preview)
         );
 
         // Compile the code to IL
         var compilation = CSharpCompilation.Create(
             "CliFxTests_DynamicAssembly_" + Guid.NewGuid(),
-            new[] { ast },
+            [ast],
-            Net70
+            Net80
                 .References
                 .All
                 .Append(MetadataReference.CreateFromFile(typeof(ICommand).Assembly.Location)),

CliFx.Benchmarks/Benchmarks.Cocona.cs

@@ -8,9 +8,9 @@ public partial class Benchmarks
     public class CoconaCommand
     {
         public void Execute(
-            [Option("str", new[] { 's' })] string? strOption,
+            [Option("str", ['s'])] string? strOption,
-            [Option("int", new[] { 'i' })] int intOption,
+            [Option("int", ['i'])] int intOption,
-            [Option("bool", new[] { 'b' })] bool boolOption
+            [Option("bool", ['b'])] bool boolOption
         ) { }
     }
 

CliFx.Benchmarks/Benchmarks.SystemCommandLine.cs

@@ -15,9 +15,9 @@ public partial class Benchmarks
         {
             var command = new RootCommand
             {
-                new Option(new[] { "--str", "-s" }) { Argument = new Argument<string?>() },
+                new Option(["--str", "-s"]) { Argument = new Argument<string?>() },
-                new Option(new[] { "--int", "-i" }) { Argument = new Argument<int>() },
+                new Option(["--int", "-i"]) { Argument = new Argument<int>() },
-                new Option(new[] { "--bool", "-b" }) { Argument = new Argument<bool>() }
+                new Option(["--bool", "-b"]) { Argument = new Argument<bool>() }
             };
 
             command.Handler = CommandHandler.Create(

CliFx.Benchmarks/Benchmarks.cs

@@ -9,7 +9,7 @@ namespace CliFx.Benchmarks;
 [Orderer(SummaryOrderPolicy.FastestToSlowest)]
 public partial class Benchmarks
 {
-    private static readonly string[] Arguments = { "--str", "hello world", "-i", "13", "-b" };
+    private static readonly string[] Arguments = ["--str", "hello world", "-i", "13", "-b"];
 
     public static void Main() =>
         BenchmarkRunner.Run<Benchmarks>(

CliFx.Tests/ApplicationSpecs.cs

@@ -32,8 +32,8 @@ public class ApplicationSpecs(ITestOutputHelper testOutput) : SpecsBase(testOutp
         var app = new CliApplicationBuilder()
             .AddCommand<NoOpCommand>()
             .AddCommandsFrom(typeof(NoOpCommand).Assembly)
-            .AddCommands(new[] { typeof(NoOpCommand) })
+            .AddCommands([typeof(NoOpCommand)])
-            .AddCommandsFrom(new[] { typeof(NoOpCommand).Assembly })
+            .AddCommandsFrom([typeof(NoOpCommand).Assembly])
             .AddCommandsFromThisAssembly()
             .AllowDebugMode()
             .AllowPreviewMode()

CliFx.Tests/CliFx.Tests.csproj

@@ -9,7 +9,7 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="Basic.Reference.Assemblies.Net70" Version="1.4.5" />
+    <PackageReference Include="Basic.Reference.Assemblies.Net80" Version="1.4.5" />
     <PackageReference Include="CliWrap" Version="3.6.4" />
     <PackageReference Include="coverlet.collector" Version="6.0.0" PrivateAssets="all" />
     <PackageReference Include="CSharpier.MsBuild" Version="0.26.5" PrivateAssets="all" />

CliFx.Tests/ConversionSpecs.cs

@@ -38,10 +38,7 @@ public class ConversionSpecs(ITestOutputHelper testOutput) : SpecsBase(testOutpu
             .Build();
 
         // Act
-        var exitCode = await application.RunAsync(
+        var exitCode = await application.RunAsync(["-f", "xyz"], new Dictionary<string, string>());
-            new[] { "-f", "xyz" },
-            new Dictionary<string, string>()
-        );
 
         // Assert
         exitCode.Should().Be(0);
@@ -78,10 +75,7 @@ public class ConversionSpecs(ITestOutputHelper testOutput) : SpecsBase(testOutpu
             .Build();
 
         // Act
-        var exitCode = await application.RunAsync(
+        var exitCode = await application.RunAsync(["-f", "xyz"], new Dictionary<string, string>());
-            new[] { "-f", "xyz" },
-            new Dictionary<string, string>()
-        );
 
         // Assert
         exitCode.Should().Be(0);
@@ -128,7 +122,7 @@ public class ConversionSpecs(ITestOutputHelper testOutput) : SpecsBase(testOutpu
 
         // Act
         var exitCode = await application.RunAsync(
-            new[] { "-f", "true", "-b", "false", "-c" },
+            ["-f", "true", "-b", "false", "-c"],
             new Dictionary<string, string>()
         );
 
@@ -167,10 +161,7 @@ public class ConversionSpecs(ITestOutputHelper testOutput) : SpecsBase(testOutpu
             .Build();
 
         // Act
-        var exitCode = await application.RunAsync(
+        var exitCode = await application.RunAsync(["-f", "32"], new Dictionary<string, string>());
-            new[] { "-f", "32" },
-            new Dictionary<string, string>()
-        );
 
         // Assert
         exitCode.Should().Be(0);
@@ -208,7 +199,7 @@ public class ConversionSpecs(ITestOutputHelper testOutput) : SpecsBase(testOutpu
 
         // Act
         var exitCode = await application.RunAsync(
-            new[] { "-f", "32.14" },
+            ["-f", "32.14"],
             new Dictionary<string, string>()
         );
 
@@ -248,7 +239,7 @@ public class ConversionSpecs(ITestOutputHelper testOutput) : SpecsBase(testOutpu
 
         // Act
         var exitCode = await application.RunAsync(
-            new[] { "-f", "1995-04-28Z" },
+            ["-f", "1995-04-28Z"],
             new Dictionary<string, string>()
         );
 
@@ -288,7 +279,7 @@ public class ConversionSpecs(ITestOutputHelper testOutput) : SpecsBase(testOutpu
 
         // Act
         var exitCode = await application.RunAsync(
-            new[] { "-f", "12:34:56" },
+            ["-f", "12:34:56"],
             new Dictionary<string, string>()
         );
 
@@ -329,10 +320,7 @@ public class ConversionSpecs(ITestOutputHelper testOutput) : SpecsBase(testOutpu
             .Build();
 
         // Act
-        var exitCode = await application.RunAsync(
+        var exitCode = await application.RunAsync(["-f", "two"], new Dictionary<string, string>());
-            new[] { "-f", "two" },
-            new Dictionary<string, string>()
-        );
 
         // Assert
         exitCode.Should().Be(0);
@@ -374,10 +362,7 @@ public class ConversionSpecs(ITestOutputHelper testOutput) : SpecsBase(testOutpu
             .Build();
 
         // Act
-        var exitCode = await application.RunAsync(
+        var exitCode = await application.RunAsync(["-b", "123"], new Dictionary<string, string>());
-            new[] { "-b", "123" },
-            new Dictionary<string, string>()
-        );
 
         // Assert
         exitCode.Should().Be(0);
@@ -421,10 +406,7 @@ public class ConversionSpecs(ITestOutputHelper testOutput) : SpecsBase(testOutpu
             .Build();
 
         // Act
-        var exitCode = await application.RunAsync(
+        var exitCode = await application.RunAsync(["-b", "two"], new Dictionary<string, string>());
-            new[] { "-b", "two" },
-            new Dictionary<string, string>()
-        );
 
         // Assert
         exitCode.Should().Be(0);
@@ -468,10 +450,7 @@ public class ConversionSpecs(ITestOutputHelper testOutput) : SpecsBase(testOutpu
             .Build();
 
         // Act
-        var exitCode = await application.RunAsync(
+        var exitCode = await application.RunAsync(["-f", "xyz"], new Dictionary<string, string>());
-            new[] { "-f", "xyz" },
-            new Dictionary<string, string>()
-        );
 
         // Assert
         exitCode.Should().Be(0);
@@ -534,7 +513,7 @@ public class ConversionSpecs(ITestOutputHelper testOutput) : SpecsBase(testOutpu
 
         // Act
         var exitCode = await application.RunAsync(
-            new[] { "-f", "hello", "-b", "world" },
+            ["-f", "hello", "-b", "world"],
             new Dictionary<string, string>()
         );
 
@@ -580,7 +559,7 @@ public class ConversionSpecs(ITestOutputHelper testOutput) : SpecsBase(testOutpu
 
         // Act
         var exitCode = await application.RunAsync(
-            new[] { "-f", "hello world" },
+            ["-f", "hello world"],
             new Dictionary<string, string>()
         );
 
@@ -622,7 +601,7 @@ public class ConversionSpecs(ITestOutputHelper testOutput) : SpecsBase(testOutpu
 
         // Act
         var exitCode = await application.RunAsync(
-            new[] { "-f", "one", "two", "three" },
+            ["-f", "one", "two", "three"],
             new Dictionary<string, string>()
         );
 
@@ -664,7 +643,7 @@ public class ConversionSpecs(ITestOutputHelper testOutput) : SpecsBase(testOutpu
 
         // Act
         var exitCode = await application.RunAsync(
-            new[] { "-f", "one", "two", "three" },
+            ["-f", "one", "two", "three"],
             new Dictionary<string, string>()
         );
 
@@ -706,7 +685,7 @@ public class ConversionSpecs(ITestOutputHelper testOutput) : SpecsBase(testOutpu
 
         // Act
         var exitCode = await application.RunAsync(
-            new[] { "-f", "one", "two", "three" },
+            ["-f", "one", "two", "three"],
             new Dictionary<string, string>()
         );
 
@@ -748,7 +727,7 @@ public class ConversionSpecs(ITestOutputHelper testOutput) : SpecsBase(testOutpu
 
         // Act
         var exitCode = await application.RunAsync(
-            new[] { "-f", "1", "13", "27" },
+            ["-f", "1", "13", "27"],
             new Dictionary<string, string>()
         );
 
@@ -787,10 +766,7 @@ public class ConversionSpecs(ITestOutputHelper testOutput) : SpecsBase(testOutpu
             .Build();
 
         // Act
-        var exitCode = await application.RunAsync(
+        var exitCode = await application.RunAsync(["-f", "xyz"], new Dictionary<string, string>());
-            new[] { "-f", "xyz" },
-            new Dictionary<string, string>()
-        );
 
         // Assert
         exitCode.Should().NotBe(0);
@@ -831,7 +807,7 @@ public class ConversionSpecs(ITestOutputHelper testOutput) : SpecsBase(testOutpu
 
         // Act
         var exitCode = await application.RunAsync(
-            new[] { "-f", "one", "two" },
+            ["-f", "one", "two"],
             new Dictionary<string, string>()
         );
 
@@ -867,7 +843,7 @@ public class ConversionSpecs(ITestOutputHelper testOutput) : SpecsBase(testOutpu
 
         // Act
         var exitCode = await application.RunAsync(
-            new[] { "-f", "12.34" },
+            ["-f", "12.34"],
             new Dictionary<string, string>()
         );
 
@@ -898,7 +874,7 @@ public class ConversionSpecs(ITestOutputHelper testOutput) : SpecsBase(testOutpu
             [Command]
             public class Command : ICommand
             {
-                [CommandOption('f', Validators = new[] {typeof(ValidatorA), typeof(ValidatorB)})]
+                [CommandOption('f', Validators = [typeof(ValidatorA), typeof(ValidatorB)])]
                 public int Foo { get; init; }
 
                 public ValueTask ExecuteAsync(IConsole console) => default;
@@ -912,10 +888,7 @@ public class ConversionSpecs(ITestOutputHelper testOutput) : SpecsBase(testOutpu
             .Build();
 
         // Act
-        var exitCode = await application.RunAsync(
+        var exitCode = await application.RunAsync(["-f", "12"], new Dictionary<string, string>());
-            new[] { "-f", "12" },
-            new Dictionary<string, string>()
-        );
 
         // Assert
         exitCode.Should().NotBe(0);
@@ -957,10 +930,7 @@ public class ConversionSpecs(ITestOutputHelper testOutput) : SpecsBase(testOutpu
             .Build();
 
         // Act
-        var exitCode = await application.RunAsync(
+        var exitCode = await application.RunAsync(["-f", "bar"], new Dictionary<string, string>());
-            new[] { "-f", "bar" },
-            new Dictionary<string, string>()
-        );
 
         // Assert
         exitCode.Should().NotBe(0);

CliFx.Tests/DirectivesSpecs.cs

@@ -63,7 +63,7 @@ public class DirectivesSpecs(ITestOutputHelper testOutput) : SpecsBase(testOutpu
 
         // Act
         var exitCode = await application.RunAsync(
-            new[] { "[preview]", "cmd", "param", "-abc", "--option", "foo" },
+            ["[preview]", "cmd", "param", "-abc", "--option", "foo"],
             new Dictionary<string, string> { ["ENV_QOP"] = "hello", ["ENV_KIL"] = "world" }
         );
 

CliFx.Tests/EnvironmentSpecs.cs

@@ -48,7 +48,7 @@ public class EnvironmentSpecs(ITestOutputHelper testOutput) : SpecsBase(testOutp
 
         // Act
         var exitCode = await application.RunAsync(
-            new[] { "--foo", "42" },
+            ["--foo", "42"],
             new Dictionary<string, string> { ["ENV_FOO"] = "100", ["ENV_BAR"] = "200" }
         );
 

CliFx.Tests/HelpTextSpecs.cs

@@ -55,10 +55,7 @@ public class HelpTextSpecs(ITestOutputHelper testOutput) : SpecsBase(testOutput)
             .Build();
 
         // Act
-        var exitCode = await application.RunAsync(
+        var exitCode = await application.RunAsync(["--help"], new Dictionary<string, string>());
-            new[] { "--help" },
-            new Dictionary<string, string>()
-        );
 
         // Assert
         exitCode.Should().Be(0);
@@ -95,10 +92,7 @@ public class HelpTextSpecs(ITestOutputHelper testOutput) : SpecsBase(testOutput)
             .Build();
 
         // Act
-        var exitCode = await application.RunAsync(
+        var exitCode = await application.RunAsync(["--help"], new Dictionary<string, string>());
-            new[] { "--help" },
-            new Dictionary<string, string>()
-        );
 
         // Assert
         exitCode.Should().Be(0);
@@ -141,7 +135,7 @@ public class HelpTextSpecs(ITestOutputHelper testOutput) : SpecsBase(testOutput)
 
         // Act
         var exitCode = await application.RunAsync(
-            new[] { "cmd", "--help" },
+            ["cmd", "--help"],
             new Dictionary<string, string>()
         );
 
@@ -186,7 +180,7 @@ public class HelpTextSpecs(ITestOutputHelper testOutput) : SpecsBase(testOutput)
 
         // Act
         var exitCode = await application.RunAsync(
-            new[] { "cmd", "sub", "--help" },
+            ["cmd", "sub", "--help"],
             new Dictionary<string, string>()
         );
 
@@ -209,7 +203,7 @@ public class HelpTextSpecs(ITestOutputHelper testOutput) : SpecsBase(testOutput)
 
         // Act
         var exitCode = await application.RunAsync(
-            new[] { "invalid-command", "--invalid-option" },
+            ["invalid-command", "--invalid-option"],
             new Dictionary<string, string>()
         );
 
@@ -235,10 +229,7 @@ public class HelpTextSpecs(ITestOutputHelper testOutput) : SpecsBase(testOutput)
             .Build();
 
         // Act
-        var exitCode = await application.RunAsync(
+        var exitCode = await application.RunAsync(["--help"], new Dictionary<string, string>());
-            new[] { "--help" },
-            new Dictionary<string, string>()
-        );
 
         // Assert
         exitCode.Should().Be(0);
@@ -268,10 +259,7 @@ public class HelpTextSpecs(ITestOutputHelper testOutput) : SpecsBase(testOutput)
             .Build();
 
         // Act
-        var exitCode = await application.RunAsync(
+        var exitCode = await application.RunAsync(["--help"], new Dictionary<string, string>());
-            new[] { "--help" },
-            new Dictionary<string, string>()
-        );
 
         // Assert
         exitCode.Should().Be(0);
@@ -307,10 +295,7 @@ public class HelpTextSpecs(ITestOutputHelper testOutput) : SpecsBase(testOutput)
             .Build();
 
         // Act
-        var exitCode = await application.RunAsync(
+        var exitCode = await application.RunAsync(["--help"], new Dictionary<string, string>());
-            new[] { "--help" },
-            new Dictionary<string, string>()
-        );
 
         // Assert
         exitCode.Should().Be(0);
@@ -349,10 +334,7 @@ public class HelpTextSpecs(ITestOutputHelper testOutput) : SpecsBase(testOutput)
             .Build();
 
         // Act
-        var exitCode = await application.RunAsync(
+        var exitCode = await application.RunAsync(["--help"], new Dictionary<string, string>());
-            new[] { "--help" },
-            new Dictionary<string, string>()
-        );
 
         // Assert
         exitCode.Should().Be(0);
@@ -398,10 +380,7 @@ public class HelpTextSpecs(ITestOutputHelper testOutput) : SpecsBase(testOutput)
             .Build();
 
         // Act
-        var exitCode = await application.RunAsync(
+        var exitCode = await application.RunAsync(["--help"], new Dictionary<string, string>());
-            new[] { "--help" },
-            new Dictionary<string, string>()
-        );
 
         // Assert
         exitCode.Should().Be(0);
@@ -440,10 +419,7 @@ public class HelpTextSpecs(ITestOutputHelper testOutput) : SpecsBase(testOutput)
             .Build();
 
         // Act
-        var exitCode = await application.RunAsync(
+        var exitCode = await application.RunAsync(["--help"], new Dictionary<string, string>());
-            new[] { "--help" },
-            new Dictionary<string, string>()
-        );
 
         // Assert
         exitCode.Should().Be(0);
@@ -481,10 +457,7 @@ public class HelpTextSpecs(ITestOutputHelper testOutput) : SpecsBase(testOutput)
             .Build();
 
         // Act
-        var exitCode = await application.RunAsync(
+        var exitCode = await application.RunAsync(["--help"], new Dictionary<string, string>());
-            new[] { "--help" },
-            new Dictionary<string, string>()
-        );
 
         // Assert
         exitCode.Should().Be(0);
@@ -523,10 +496,7 @@ public class HelpTextSpecs(ITestOutputHelper testOutput) : SpecsBase(testOutput)
             .Build();
 
         // Act
-        var exitCode = await application.RunAsync(
+        var exitCode = await application.RunAsync(["--help"], new Dictionary<string, string>());
-            new[] { "--help" },
-            new Dictionary<string, string>()
-        );
 
         // Assert
         exitCode.Should().Be(0);
@@ -566,7 +536,7 @@ public class HelpTextSpecs(ITestOutputHelper testOutput) : SpecsBase(testOutput)
 
         // Act
         var exitCode = await application.RunAsync(
-            new[] { "cmd", "--help" },
+            ["cmd", "--help"],
             new Dictionary<string, string>()
         );
 
@@ -609,10 +579,7 @@ public class HelpTextSpecs(ITestOutputHelper testOutput) : SpecsBase(testOutput)
             .Build();
 
         // Act
-        var exitCode = await application.RunAsync(
+        var exitCode = await application.RunAsync(["--help"], new Dictionary<string, string>());
-            new[] { "--help" },
-            new Dictionary<string, string>()
-        );
 
         // Assert
         exitCode.Should().Be(0);
@@ -665,10 +632,7 @@ public class HelpTextSpecs(ITestOutputHelper testOutput) : SpecsBase(testOutput)
             .Build();
 
         // Act
-        var exitCode = await application.RunAsync(
+        var exitCode = await application.RunAsync(["--help"], new Dictionary<string, string>());
-            new[] { "--help" },
-            new Dictionary<string, string>()
-        );
 
         // Assert
         exitCode.Should().Be(0);
@@ -721,10 +685,7 @@ public class HelpTextSpecs(ITestOutputHelper testOutput) : SpecsBase(testOutput)
             .Build();
 
         // Act
-        var exitCode = await application.RunAsync(
+        var exitCode = await application.RunAsync(["--help"], new Dictionary<string, string>());
-            new[] { "--help" },
-            new Dictionary<string, string>()
-        );
 
         // Assert
         exitCode.Should().Be(0);
@@ -777,10 +738,7 @@ public class HelpTextSpecs(ITestOutputHelper testOutput) : SpecsBase(testOutput)
             .Build();
 
         // Act
-        var exitCode = await application.RunAsync(
+        var exitCode = await application.RunAsync(["--help"], new Dictionary<string, string>());
-            new[] { "--help" },
-            new Dictionary<string, string>()
-        );
 
         // Assert
         exitCode.Should().Be(0);
@@ -846,10 +804,7 @@ public class HelpTextSpecs(ITestOutputHelper testOutput) : SpecsBase(testOutput)
             .Build();
 
         // Act
-        var exitCode = await application.RunAsync(
+        var exitCode = await application.RunAsync(["--help"], new Dictionary<string, string>());
-            new[] { "--help" },
-            new Dictionary<string, string>()
-        );
 
         // Assert
         exitCode.Should().Be(0);
@@ -927,10 +882,7 @@ public class HelpTextSpecs(ITestOutputHelper testOutput) : SpecsBase(testOutput)
             .Build();
 
         // Act
-        var exitCode = await application.RunAsync(
+        var exitCode = await application.RunAsync(["--help"], new Dictionary<string, string>());
-            new[] { "--help" },
-            new Dictionary<string, string>()
-        );
 
         // Assert
         exitCode.Should().Be(0);
@@ -1001,10 +953,7 @@ public class HelpTextSpecs(ITestOutputHelper testOutput) : SpecsBase(testOutput)
             .Build();
 
         // Act
-        var exitCode = await application.RunAsync(
+        var exitCode = await application.RunAsync(["--help"], new Dictionary<string, string>());
-            new[] { "--help" },
-            new Dictionary<string, string>()
-        );
 
         // Assert
         exitCode.Should().Be(0);
@@ -1035,10 +984,7 @@ public class HelpTextSpecs(ITestOutputHelper testOutput) : SpecsBase(testOutput)
             .Build();
 
         // Act
-        var exitCode = await application.RunAsync(
+        var exitCode = await application.RunAsync(["--version"], new Dictionary<string, string>());
-            new[] { "--version" },
-            new Dictionary<string, string>()
-        );
 
         // Assert
         exitCode.Should().Be(0);

CliFx.Tests/OptionBindingSpecs.cs

@@ -39,10 +39,7 @@ public class OptionBindingSpecs(ITestOutputHelper testOutput) : SpecsBase(testOu
             .Build();
 
         // Act
-        var exitCode = await application.RunAsync(
+        var exitCode = await application.RunAsync(["--foo"], new Dictionary<string, string>());
-            new[] { "--foo" },
-            new Dictionary<string, string>()
-        );
 
         // Assert
         exitCode.Should().Be(0);
@@ -79,7 +76,7 @@ public class OptionBindingSpecs(ITestOutputHelper testOutput) : SpecsBase(testOu
             .Build();
 
         // Act
-        var exitCode = await application.RunAsync(new[] { "-f" }, new Dictionary<string, string>());
+        var exitCode = await application.RunAsync(["-f"], new Dictionary<string, string>());
 
         // Assert
         exitCode.Should().Be(0);
@@ -122,7 +119,7 @@ public class OptionBindingSpecs(ITestOutputHelper testOutput) : SpecsBase(testOu
 
         // Act
         var exitCode = await application.RunAsync(
-            new[] { "--foo", "one", "--bar", "two" },
+            ["--foo", "one", "--bar", "two"],
             new Dictionary<string, string>()
         );
 
@@ -167,7 +164,7 @@ public class OptionBindingSpecs(ITestOutputHelper testOutput) : SpecsBase(testOu
 
         // Act
         var exitCode = await application.RunAsync(
-            new[] { "-f", "one", "-b", "two" },
+            ["-f", "one", "-b", "two"],
             new Dictionary<string, string>()
         );
 
@@ -212,7 +209,7 @@ public class OptionBindingSpecs(ITestOutputHelper testOutput) : SpecsBase(testOu
 
         // Act
         var exitCode = await application.RunAsync(
-            new[] { "-fb", "value" },
+            ["-fb", "value"],
             new Dictionary<string, string>()
         );
 
@@ -254,7 +251,7 @@ public class OptionBindingSpecs(ITestOutputHelper testOutput) : SpecsBase(testOu
 
         // Act
         var exitCode = await application.RunAsync(
-            new[] { "--foo", "one", "two", "three" },
+            ["--foo", "one", "two", "three"],
             new Dictionary<string, string>()
         );
 
@@ -296,7 +293,7 @@ public class OptionBindingSpecs(ITestOutputHelper testOutput) : SpecsBase(testOu
 
         // Act
         var exitCode = await application.RunAsync(
-            new[] { "-f", "one", "two", "three" },
+            ["-f", "one", "two", "three"],
             new Dictionary<string, string>()
         );
 
@@ -338,7 +335,7 @@ public class OptionBindingSpecs(ITestOutputHelper testOutput) : SpecsBase(testOu
 
         // Act
         var exitCode = await application.RunAsync(
-            new[] { "--foo", "one", "--foo", "two", "--foo", "three" },
+            ["--foo", "one", "--foo", "two", "--foo", "three"],
             new Dictionary<string, string>()
         );
 
@@ -380,7 +377,7 @@ public class OptionBindingSpecs(ITestOutputHelper testOutput) : SpecsBase(testOu
 
         // Act
         var exitCode = await application.RunAsync(
-            new[] { "-f", "one", "-f", "two", "-f", "three" },
+            ["-f", "one", "-f", "two", "-f", "three"],
             new Dictionary<string, string>()
         );
 
@@ -422,7 +419,7 @@ public class OptionBindingSpecs(ITestOutputHelper testOutput) : SpecsBase(testOu
 
         // Act
         var exitCode = await application.RunAsync(
-            new[] { "--foo", "one", "-f", "two", "--foo", "three" },
+            ["--foo", "one", "-f", "two", "--foo", "three"],
             new Dictionary<string, string>()
         );
 
@@ -467,7 +464,7 @@ public class OptionBindingSpecs(ITestOutputHelper testOutput) : SpecsBase(testOu
 
         // Act
         var exitCode = await application.RunAsync(
-            new[] { "--foo", "one" },
+            ["--foo", "one"],
             new Dictionary<string, string>()
         );
 
@@ -541,7 +538,7 @@ public class OptionBindingSpecs(ITestOutputHelper testOutput) : SpecsBase(testOu
             .Build();
 
         // Act
-        var exitCode = await application.RunAsync(new[] { "--foo", "42", "--bar", "--baz", "xyz" });
+        var exitCode = await application.RunAsync(["--foo", "42", "--bar", "--baz", "xyz"]);
 
         // Assert
         exitCode.Should().Be(0);
@@ -579,7 +576,7 @@ public class OptionBindingSpecs(ITestOutputHelper testOutput) : SpecsBase(testOu
 
         // Act
         var exitCode = await application.RunAsync(
-            new[] { "--foo", "-13" },
+            ["--foo", "-13"],
             new Dictionary<string, string>()
         );
 
@@ -650,10 +647,7 @@ public class OptionBindingSpecs(ITestOutputHelper testOutput) : SpecsBase(testOu
             .Build();
 
         // Act
-        var exitCode = await application.RunAsync(
+        var exitCode = await application.RunAsync(["--foo"], new Dictionary<string, string>());
-            new[] { "--foo" },
-            new Dictionary<string, string>()
-        );
 
         // Assert
         exitCode.Should().NotBe(0);
@@ -686,10 +680,7 @@ public class OptionBindingSpecs(ITestOutputHelper testOutput) : SpecsBase(testOu
             .Build();
 
         // Act
-        var exitCode = await application.RunAsync(
+        var exitCode = await application.RunAsync(["--foo"], new Dictionary<string, string>());
-            new[] { "--foo" },
-            new Dictionary<string, string>()
-        );
 
         // Assert
         exitCode.Should().NotBe(0);
@@ -723,7 +714,7 @@ public class OptionBindingSpecs(ITestOutputHelper testOutput) : SpecsBase(testOu
 
         // Act
         var exitCode = await application.RunAsync(
-            new[] { "--foo", "one", "--bar", "two" },
+            ["--foo", "one", "--bar", "two"],
             new Dictionary<string, string>()
         );
 
@@ -759,7 +750,7 @@ public class OptionBindingSpecs(ITestOutputHelper testOutput) : SpecsBase(testOu
 
         // Act
         var exitCode = await application.RunAsync(
-            new[] { "--foo", "one", "two", "three" },
+            ["--foo", "one", "two", "three"],
             new Dictionary<string, string>()
         );
 

CliFx.Tests/ParameterBindingSpecs.cs

@@ -43,10 +43,7 @@ public class ParameterBindingSpecs(ITestOutputHelper testOutput) : SpecsBase(tes
             .Build();
 
         // Act
-        var exitCode = await application.RunAsync(
+        var exitCode = await application.RunAsync(["one", "two"], new Dictionary<string, string>());
-            new[] { "one", "two" },
-            new Dictionary<string, string>()
-        );
 
         // Assert
         exitCode.Should().Be(0);
@@ -98,7 +95,7 @@ public class ParameterBindingSpecs(ITestOutputHelper testOutput) : SpecsBase(tes
 
         // Act
         var exitCode = await application.RunAsync(
-            new[] { "one", "two", "three", "four", "five", "--boo", "xxx" },
+            ["one", "two", "three", "four", "five", "--boo", "xxx"],
             new Dictionary<string, string>()
         );
 
@@ -138,10 +135,7 @@ public class ParameterBindingSpecs(ITestOutputHelper testOutput) : SpecsBase(tes
             .Build();
 
         // Act
-        var exitCode = await application.RunAsync(
+        var exitCode = await application.RunAsync(["one"], new Dictionary<string, string>());
-            new[] { "one" },
-            new Dictionary<string, string>()
-        );
 
         // Assert
         exitCode.Should().NotBe(0);
@@ -177,10 +171,7 @@ public class ParameterBindingSpecs(ITestOutputHelper testOutput) : SpecsBase(tes
             .Build();
 
         // Act
-        var exitCode = await application.RunAsync(
+        var exitCode = await application.RunAsync(["one"], new Dictionary<string, string>());
-            new[] { "one" },
-            new Dictionary<string, string>()
-        );
 
         // Assert
         exitCode.Should().NotBe(0);
@@ -222,10 +213,7 @@ public class ParameterBindingSpecs(ITestOutputHelper testOutput) : SpecsBase(tes
             .Build();
 
         // Act
-        var exitCode = await application.RunAsync(
+        var exitCode = await application.RunAsync(["abc"], new Dictionary<string, string>());
-            new[] { "abc" },
-            new Dictionary<string, string>()
-        );
 
         // Assert
         exitCode.Should().Be(0);
@@ -262,7 +250,7 @@ public class ParameterBindingSpecs(ITestOutputHelper testOutput) : SpecsBase(tes
 
         // Act
         var exitCode = await application.RunAsync(
-            new[] { "one", "two", "three" },
+            ["one", "two", "three"],
             new Dictionary<string, string>()
         );
 

CliFx.Tests/RoutingSpecs.cs

@@ -112,10 +112,7 @@ public class RoutingSpecs(ITestOutputHelper testOutput) : SpecsBase(testOutput)
             .Build();
 
         // Act
-        var exitCode = await application.RunAsync(
+        var exitCode = await application.RunAsync(["cmd"], new Dictionary<string, string>());
-            new[] { "cmd" },
-            new Dictionary<string, string>()
-        );
 
         // Assert
         exitCode.Should().Be(0);
@@ -170,7 +167,7 @@ public class RoutingSpecs(ITestOutputHelper testOutput) : SpecsBase(testOutput)
 
         // Act
         var exitCode = await application.RunAsync(
-            new[] { "cmd", "child" },
+            ["cmd", "child"],
             new Dictionary<string, string>()
         );
 

CliFx.Tests/Utils/DynamicCommandBuilder.cs

@@ -49,14 +49,14 @@ internal static class DynamicCommandBuilder
         // Parse the source code
         var ast = SyntaxFactory.ParseSyntaxTree(
             SourceText.From(sourceCodeWithUsings),
-            CSharpParseOptions.Default
+            CSharpParseOptions.Default.WithLanguageVersion(LanguageVersion.Preview)
         );
 
         // Compile the code to IL
         var compilation = CSharpCompilation.Create(
             "CliFxTests_DynamicAssembly_" + Guid.NewGuid(),
-            new[] { ast },
+            [ast],
-            Net70
+            Net80
                 .References
                 .All
                 .Append(MetadataReference.CreateFromFile(typeof(ICommand).Assembly.Location))

CliFx/ApplicationConfiguration.cs

@@ -6,34 +6,24 @@ namespace CliFx;
 /// <summary>
 /// Configuration of an application.
 /// </summary>
-public class ApplicationConfiguration
+public class ApplicationConfiguration(
+    IReadOnlyList<Type> commandTypes,
+    bool isDebugModeAllowed,
+    bool isPreviewModeAllowed
+)
 {
     /// <summary>
     /// Command types defined in the application.
     /// </summary>
-    public IReadOnlyList<Type> CommandTypes { get; }
+    public IReadOnlyList<Type> CommandTypes { get; } = commandTypes;
 
     /// <summary>
     /// Whether debug mode is allowed in the application.
     /// </summary>
-    public bool IsDebugModeAllowed { get; }
+    public bool IsDebugModeAllowed { get; } = isDebugModeAllowed;
 
     /// <summary>
     /// Whether preview mode is allowed in the application.
     /// </summary>
-    public bool IsPreviewModeAllowed { get; }
+    public bool IsPreviewModeAllowed { get; } = isPreviewModeAllowed;
-
-    /// <summary>
-    /// Initializes an instance of <see cref="ApplicationConfiguration" />.
-    /// </summary>
-    public ApplicationConfiguration(
-        IReadOnlyList<Type> commandTypes,
-        bool isDebugModeAllowed,
-        bool isPreviewModeAllowed
-    )
-    {
-        CommandTypes = commandTypes;
-        IsDebugModeAllowed = isDebugModeAllowed;
-        IsPreviewModeAllowed = isPreviewModeAllowed;
-    }
 }

CliFx/ApplicationMetadata.cs

@@ -3,41 +3,30 @@
 /// <summary>
 /// Metadata associated with an application.
 /// </summary>
-public class ApplicationMetadata
+public class ApplicationMetadata(
+    string title,
+    string executableName,
+    string version,
+    string? description
+)
 {
     /// <summary>
     /// Application title.
     /// </summary>
-    public string Title { get; }
+    public string Title { get; } = title;
 
     /// <summary>
     /// Application executable name.
     /// </summary>
-    public string ExecutableName { get; }
+    public string ExecutableName { get; } = executableName;
 
     /// <summary>
     /// Application version.
     /// </summary>
-    public string Version { get; }
+    public string Version { get; } = version;
 
     /// <summary>
     /// Application description.
     /// </summary>
-    public string? Description { get; }
+    public string? Description { get; } = description;
-
-    /// <summary>
-    /// Initializes an instance of <see cref="ApplicationMetadata" />.
-    /// </summary>
-    public ApplicationMetadata(
-        string title,
-        string executableName,
-        string version,
-        string? description
-    )
-    {
-        Title = title;
-        ExecutableName = executableName;
-        Version = version;
-        Description = description;
-    }
 }

CliFx/Attributes/CommandParameterAttribute.cs

@@ -7,7 +7,7 @@ namespace CliFx.Attributes;
 /// Annotates a property that defines a command parameter.
 /// </summary>
 [AttributeUsage(AttributeTargets.Property)]
-public sealed class CommandParameterAttribute : Attribute
+public sealed class CommandParameterAttribute(int order) : Attribute
 {
     /// <summary>
     /// Parameter order.
@@ -18,7 +18,7 @@ public sealed class CommandParameterAttribute : Attribute
     /// Parameter whose type is a non-scalar (e.g. array), must always be the last in order.
     /// Only one non-scalar parameter is allowed in a command.
     /// </remarks>
-    public int Order { get; }
+    public int Order { get; } = order;
 
     /// <summary>
     /// Whether this parameter is required (default: <c>true</c>).
@@ -62,12 +62,4 @@ public sealed class CommandParameterAttribute : Attribute
     /// Validators must derive from <see cref="BindingValidator{T}" />.
     /// </remarks>
     public Type[] Validators { get; set; } = Array.Empty<Type>();
-
-    /// <summary>
-    /// Initializes an instance of <see cref="CommandParameterAttribute" />.
-    /// </summary>
-    public CommandParameterAttribute(int order)
-    {
-        Order = order;
-    }
 }

CliFx/CliApplication.cs

@@ -17,40 +17,24 @@ namespace CliFx;
 /// <summary>
 /// Command-line application facade.
 /// </summary>
-public class CliApplication
+public class CliApplication(
+    ApplicationMetadata metadata,
+    ApplicationConfiguration configuration,
+    IConsole console,
+    ITypeActivator typeActivator
+)
 {
+    private readonly CommandBinder _commandBinder = new(typeActivator);
+
     /// <summary>
     /// Application metadata.
     /// </summary>
-    public ApplicationMetadata Metadata { get; }
+    public ApplicationMetadata Metadata { get; } = metadata;
 
     /// <summary>
     /// Application configuration.
     /// </summary>
-    public ApplicationConfiguration Configuration { get; }
+    public ApplicationConfiguration Configuration { get; } = configuration;
-
-    private readonly IConsole _console;
-    private readonly ITypeActivator _typeActivator;
-
-    private readonly CommandBinder _commandBinder;
-
-    /// <summary>
-    /// Initializes an instance of <see cref="CliApplication" />.
-    /// </summary>
-    public CliApplication(
-        ApplicationMetadata metadata,
-        ApplicationConfiguration configuration,
-        IConsole console,
-        ITypeActivator typeActivator
-    )
-    {
-        Metadata = metadata;
-        Configuration = configuration;
-        _console = console;
-        _typeActivator = typeActivator;
-
-        _commandBinder = new CommandBinder(typeActivator);
-    }
 
     private bool IsDebugModeEnabled(CommandInput commandInput) =>
         Configuration.IsDebugModeAllowed && commandInput.IsDebugDirectiveSpecified;
@@ -70,9 +54,9 @@ public class CliApplication
 
     private async ValueTask PromptDebuggerAsync()
     {
-        using (_console.WithForegroundColor(ConsoleColor.Green))
+        using (console.WithForegroundColor(ConsoleColor.Green))
         {
-            _console
+            console
                 .Output
                 .WriteLine(
                     $"Attach the debugger to process with ID {ProcessEx.GetCurrentProcessId()} to continue."
@@ -93,7 +77,7 @@ public class CliApplication
     {
         // Console colors may have already been overridden by the parent process,
         // so we need to reset it to make sure that everything we write looks properly.
-        _console.ResetColor();
+        console.ResetColor();
 
         // Handle the debug directive
         if (IsDebugModeEnabled(commandInput))
@@ -104,7 +88,7 @@ public class CliApplication
         // Handle the preview directive
         if (IsPreviewModeEnabled(commandInput))
         {
-            _console.Output.WriteCommandInput(commandInput);
+            console.Output.WriteCommandInput(commandInput);
             return 0;
         }
 
@@ -128,7 +112,7 @@ public class CliApplication
         var commandInstance =
             commandSchema == FallbackDefaultCommand.Schema
                 ? new FallbackDefaultCommand() // bypass the activator
-                : _typeActivator.CreateInstance<ICommand>(commandSchema.Type);
+                : typeActivator.CreateInstance<ICommand>(commandSchema.Type);
 
         // Assemble the help context
         var helpContext = new HelpContext(
@@ -141,14 +125,14 @@ public class CliApplication
         // Handle the help option
         if (ShouldShowHelpText(commandSchema, commandInput))
         {
-            _console.Output.WriteHelpText(helpContext);
+            console.Output.WriteHelpText(helpContext);
             return 0;
         }
 
         // Handle the version option
         if (ShouldShowVersionText(commandSchema, commandInput))
         {
-            _console.Output.WriteLine(Metadata.Version);
+            console.Output.WriteLine(Metadata.Version);
             return 0;
         }
 
@@ -160,18 +144,18 @@ public class CliApplication
         {
             // Bind and execute the command
             _commandBinder.Bind(commandInput, commandSchema, commandInstance);
-            await commandInstance.ExecuteAsync(_console);
+            await commandInstance.ExecuteAsync(console);
 
             return 0;
         }
         catch (CliFxException ex)
         {
-            _console.Error.WriteException(ex);
+            console.Error.WriteException(ex);
 
             if (ex.ShowHelp)
             {
-                _console.Output.WriteLine();
+                console.Output.WriteLine();
-                _console.Output.WriteHelpText(helpContext);
+                console.Output.WriteHelpText(helpContext);
             }
 
             return ex.ExitCode;
@@ -211,7 +195,7 @@ public class CliApplication
         // developer, so we don't swallow them in that case.
         catch (Exception ex) when (!Debugger.IsAttached)
         {
-            _console.Error.WriteException(ex);
+            console.Error.WriteException(ex);
             return 1;
         }
     }

CliFx/CliApplicationBuilder.cs

@@ -16,7 +16,7 @@ namespace CliFx;
 /// </summary>
 public partial class CliApplicationBuilder
 {
-    private readonly HashSet<Type> _commandTypes = new();
+    private readonly HashSet<Type> _commandTypes = [];
 
     private bool _isDebugModeAllowed = true;
     private bool _isPreviewModeAllowed = true;

CliFx/CommandBinder.cs

@@ -74,27 +74,24 @@ internal class CommandBinder(ITypeActivator typeActivator)
         }
 
         // String-constructable (FileInfo, etc)
-        var stringConstructor = targetType.GetConstructor(new[] { typeof(string) });
+        var stringConstructor = targetType.GetConstructor([typeof(string)]);
         if (stringConstructor is not null)
         {
-            return stringConstructor.Invoke(new object?[] { rawValue });
+            return stringConstructor.Invoke([rawValue]);
         }
 
         // String-parseable (with IFormatProvider)
         var parseMethodWithFormatProvider = targetType.TryGetStaticParseMethod(true);
         if (parseMethodWithFormatProvider is not null)
         {
-            return parseMethodWithFormatProvider.Invoke(
+            return parseMethodWithFormatProvider.Invoke(null, [rawValue, _formatProvider]);
-                null,
-                new object?[] { rawValue, _formatProvider }
-            );
         }
 
         // String-parseable (without IFormatProvider)
         var parseMethod = targetType.TryGetStaticParseMethod();
         if (parseMethod is not null)
         {
-            return parseMethod.Invoke(null, new object?[] { rawValue });
+            return parseMethod.Invoke(null, [rawValue]);
         }
 
         throw CliFxException.InternalError(
@@ -126,10 +123,10 @@ internal class CommandBinder(ITypeActivator typeActivator)
         }
 
         // Array-constructable (List<T>, HashSet<T>, etc)
-        var arrayConstructor = targetEnumerableType.GetConstructor(new[] { arrayType });
+        var arrayConstructor = targetEnumerableType.GetConstructor([arrayType]);
         if (arrayConstructor is not null)
         {
-            return arrayConstructor.Invoke(new object?[] { array });
+            return arrayConstructor.Invoke([array]);
         }
 
         throw CliFxException.InternalError(
@@ -263,12 +260,9 @@ internal class CommandBinder(ITypeActivator typeActivator)
             if (parameterSchema.Property.IsScalar())
             {
                 var parameterInput = commandInput.Parameters[position];
-
+                BindMember(parameterSchema, commandInstance, [parameterInput.Value]);
-                var rawValues = new[] { parameterInput.Value };
-                BindMember(parameterSchema, commandInstance, rawValues);
 
                 position++;
-
                 remainingParameterInputs.Remove(parameterInput);
             }
             // Non-scalar: take all remaining inputs starting from the current position
@@ -276,11 +270,13 @@ internal class CommandBinder(ITypeActivator typeActivator)
             {
                 var parameterInputs = commandInput.Parameters.Skip(position).ToArray();
 
-                var rawValues = parameterInputs.Select(p => p.Value).ToArray();
+                BindMember(
-                BindMember(parameterSchema, commandInstance, rawValues);
+                    parameterSchema,
+                    commandInstance,
+                    parameterInputs.Select(p => p.Value).ToArray()
+                );
 
                 position += parameterInputs.Length;
-
                 remainingParameterInputs.RemoveRange(parameterInputs);
             }
 
@@ -347,7 +343,7 @@ internal class CommandBinder(ITypeActivator typeActivator)
             else if (environmentVariableInput is not null)
             {
                 var rawValues = optionSchema.Property.IsScalar()
-                    ? new[] { environmentVariableInput.Value }
+                    ? [environmentVariableInput.Value]
                     : environmentVariableInput.SplitValues();
 
                 BindMember(optionSchema, commandInstance, rawValues);

CliFx/Exceptions/CliFxException.cs

@@ -5,7 +5,12 @@ namespace CliFx.Exceptions;
 /// <summary>
 /// Exception thrown when there is an error during application execution.
 /// </summary>
-public partial class CliFxException : Exception
+public partial class CliFxException(
+    string message,
+    int exitCode = CliFxException.DefaultExitCode,
+    bool showHelp = false,
+    Exception? innerException = null
+) : Exception(message, innerException)
 {
     internal const int DefaultExitCode = 1;
 
@@ -13,33 +18,17 @@ public partial class CliFxException : Exception
     // provides a default message that is not very useful.
     // This property is used to identify whether this instance was created with
     // a custom message, so that we can avoid printing the default message.
-    internal bool HasCustomMessage { get; }
+    internal bool HasCustomMessage { get; } = !string.IsNullOrWhiteSpace(message);
 
     /// <summary>
     /// Returned exit code.
     /// </summary>
-    public int ExitCode { get; }
+    public int ExitCode { get; } = exitCode;
 
     /// <summary>
     /// Whether to show the help text before exiting.
     /// </summary>
-    public bool ShowHelp { get; }
+    public bool ShowHelp { get; } = showHelp;
-
-    /// <summary>
-    /// Initializes an instance of <see cref="CliFxException" />.
-    /// </summary>
-    public CliFxException(
-        string message,
-        int exitCode = DefaultExitCode,
-        bool showHelp = false,
-        Exception? innerException = null
-    )
-        : base(message, innerException)
-    {
-        HasCustomMessage = !string.IsNullOrWhiteSpace(message);
-        ExitCode = exitCode;
-        ShowHelp = showHelp;
-    }
 }
 
 public partial class CliFxException

CliFx/Exceptions/CommandException.cs

@@ -6,16 +6,9 @@ namespace CliFx.Exceptions;
 /// Exception thrown when a command cannot proceed with its normal execution due to an error.
 /// Use this exception to report an error to the console and return a specific exit code.
 /// </summary>
-public class CommandException : CliFxException
+public class CommandException(
-{
+    string message,
-    /// <summary>
+    int exitCode = CliFxException.DefaultExitCode,
-    /// Initializes an instance of <see cref="CommandException" />.
+    bool showHelp = false,
-    /// </summary>
+    Exception? innerException = null
-    public CommandException(
+) : CliFxException(message, exitCode, showHelp, innerException);
-        string message,
-        int exitCode = DefaultExitCode,
-        bool showHelp = false,
-        Exception? innerException = null
-    )
-        : base(message, exitCode, showHelp, innerException) { }
-}

CliFx/Extensibility/BindingValidationError.cs

@@ -3,15 +3,10 @@
 /// <summary>
 /// Represents a validation error.
 /// </summary>
-public class BindingValidationError
+public class BindingValidationError(string message)
 {
     /// <summary>
     /// Error message shown to the user.
     /// </summary>
-    public string Message { get; }
+    public string Message { get; } = message;
-
-    /// <summary>
-    /// Initializes an instance of <see cref="BindingValidationError" />.
-    /// </summary>
-    public BindingValidationError(string message) => Message = message;
 }

CliFx/Infrastructure/ConsoleReader.cs

@@ -11,28 +11,20 @@ namespace CliFx.Infrastructure;
 /// </summary>
 // Both the underlying stream AND the stream reader must be synchronized!
 // https://github.com/Tyrrrz/CliFx/issues/123
-public partial class ConsoleReader : StreamReader
+public partial class ConsoleReader(IConsole console, Stream stream, Encoding encoding)
+    : StreamReader(stream, encoding, false, 4096)
 {
-    /// <summary>
-    /// Console that owns this stream.
-    /// </summary>
-    public IConsole Console { get; }
-
-    /// <summary>
-    /// Initializes an instance of <see cref="ConsoleReader" />.
-    /// </summary>
-    public ConsoleReader(IConsole console, Stream stream, Encoding encoding)
-        : base(stream, encoding, false, 4096)
-    {
-        Console = console;
-    }
-
     /// <summary>
     /// Initializes an instance of <see cref="ConsoleReader" />.
     /// </summary>
     public ConsoleReader(IConsole console, Stream stream)
         : this(console, stream, System.Console.InputEncoding) { }
 
+    /// <summary>
+    /// Console that owns this stream.
+    /// </summary>
+    public IConsole Console { get; } = console;
+
     // The following overrides are required to establish thread-safe behavior
     // in methods deriving from StreamReader.
 

CliFx/Infrastructure/ConsoleWriter.cs

@@ -12,28 +12,20 @@ namespace CliFx.Infrastructure;
 /// </summary>
 // Both the underlying stream AND the stream writer must be synchronized!
 // https://github.com/Tyrrrz/CliFx/issues/123
-public partial class ConsoleWriter : StreamWriter
+public partial class ConsoleWriter(IConsole console, Stream stream, Encoding encoding)
+    : StreamWriter(stream, encoding.WithoutPreamble(), 256)
 {
-    /// <summary>
-    /// Console that owns this stream.
-    /// </summary>
-    public IConsole Console { get; }
-
-    /// <summary>
-    /// Initializes an instance of <see cref="ConsoleWriter" />.
-    /// </summary>
-    public ConsoleWriter(IConsole console, Stream stream, Encoding encoding)
-        : base(stream, encoding.WithoutPreamble(), 256)
-    {
-        Console = console;
-    }
-
     /// <summary>
     /// Initializes an instance of <see cref="ConsoleWriter" />.
     /// </summary>
     public ConsoleWriter(IConsole console, Stream stream)
         : this(console, stream, System.Console.OutputEncoding) { }
 
+    /// <summary>
+    /// Console that owns this stream.
+    /// </summary>
+    public IConsole Console { get; } = console;
+
     // The following overrides are required to establish thread-safe behavior
     // in methods deriving from StreamWriter.
 

CliFx/Infrastructure/DelegateTypeActivator.cs

@@ -6,20 +6,12 @@ namespace CliFx.Infrastructure;
 /// <summary>
 /// Implementation of <see cref="ITypeActivator" /> that instantiates an object by using a predefined delegate.
 /// </summary>
-public class DelegateTypeActivator : ITypeActivator
+public class DelegateTypeActivator(Func<Type, object> createInstance) : ITypeActivator
 {
-    private readonly Func<Type, object> _createInstance;
-
-    /// <summary>
-    /// Initializes an instance of <see cref="DelegateTypeActivator" />.
-    /// </summary>
-    public DelegateTypeActivator(Func<Type, object> createInstance) =>
-        _createInstance = createInstance;
-
     /// <inheritdoc />
     public object CreateInstance(Type type)
     {
-        var instance = _createInstance(type);
+        var instance = createInstance(type);
 
         if (instance is null)
         {

CliFx/Input/CommandInput.cs

@@ -160,7 +160,7 @@ internal partial class CommandInput
                     result.Add(new OptionInput(lastOptionIdentifier, lastOptionValues));
 
                 lastOptionIdentifier = argument[2..];
-                lastOptionValues = new List<string>();
+                lastOptionValues = [];
             }
             // Short name
             else if (argument.StartsWith('-') && argument.Length > 1 && char.IsLetter(argument[1]))
@@ -172,7 +172,7 @@ internal partial class CommandInput
                         result.Add(new OptionInput(lastOptionIdentifier, lastOptionValues));
 
                     lastOptionIdentifier = identifier.AsString();
-                    lastOptionValues = new List<string>();
+                    lastOptionValues = [];
                 }
             }
             // Value