#1718 TestConsole can now be configured and accessed in CommandAppTester (#1803)

* TestConsole can now be configured and accessed in CommandAppTester
* Add test with mocked user inputs for interactive command
* Add documentation for using the CommandAppTester

Co-authored-by: Patrik Svensson <patriksvensson@users.noreply.github.com>
Co-authored-by: Marek Magath <Marek.Magath@solarwinds.com>

docs/input/cli/unit-testing.md

@@ -63,6 +63,90 @@ The following example validates the exit code and terminal output of a `Spectre.
     }
 ```
 
+The following example demonstrates how to mock user inputs for an interactive command.
+This test (InteractiveCommand_WithMockedUserInputs_ProducesExpectedOutput) simulates user interactions by pushing predefined inputs to the console, then verifies that the resulting output is as expected.
+
+```csharp
+public sealed class InteractiveCommandTests
+{
+    private sealed class InteractiveCommand : Command
+    {
+        private readonly IAnsiConsole _console;
+
+        public InteractiveCommand(IAnsiConsole console)
+        {
+            _console = console;
+        }
+
+        public override int Execute(CommandContext context)
+        {
+            var fruits = _console.Prompt(
+                new MultiSelectionPrompt<string>()
+                    .Title("What are your [green]favorite fruits[/]?")
+                    .NotRequired() // Not required to have a favorite fruit
+                    .PageSize(10)
+                    .MoreChoicesText("[grey](Move up and down to reveal more fruits)[/]")
+                    .InstructionsText(
+                        "[grey](Press [blue]<space>[/] to toggle a fruit, " +
+                        "[green]<enter>[/] to accept)[/]")
+                    .AddChoices(new[] {
+                        "Apple", "Apricot", "Avocado",
+                        "Banana", "Blackcurrant", "Blueberry",
+                        "Cherry", "Cloudberry", "Coconut",
+                    }));
+
+            var fruit = _console.Prompt(
+                new SelectionPrompt<string>()
+                    .Title("What's your [green]favorite fruit[/]?")
+                    .PageSize(10)
+                    .MoreChoicesText("[grey](Move up and down to reveal more fruits)[/]")
+                    .AddChoices(new[] {
+                        "Apple", "Apricot", "Avocado",
+                        "Banana", "Blackcurrant", "Blueberry",
+                        "Cherry", "Cloudberry", "Cocunut",
+                    }));
+
+            var name = _console.Ask<string>("What's your name?");
+
+            _console.WriteLine($"[{string.Join(',', fruits)};{fruit};{name}]");
+
+            return 0;
+        }
+    }
+
+    [Fact]
+    public void InteractiveCommand_WithMockedUserInputs_ProducesExpectedOutput()
+    {
+        // Given
+        TestConsole console = new();
+        console.Interactive();
+
+        // Your mocked inputs must always end with "Enter" for each prompt!
+
+        // Multi selection prompt: Choose first option
+        console.Input.PushKey(ConsoleKey.Spacebar);
+        console.Input.PushKey(ConsoleKey.Enter);
+
+        // Selection prompt: Choose second option
+        console.Input.PushKey(ConsoleKey.DownArrow);
+        console.Input.PushKey(ConsoleKey.Enter);
+
+        // Ask text prompt: Enter name
+        console.Input.PushTextWithEnter("Spectre Console");
+
+        var app = new CommandAppTester(null, new CommandAppTesterSettings(), console);
+        app.SetDefaultCommand<InteractiveCommand>();
+
+        // When
+        var result = app.Run();
+
+        // Then
+        result.ExitCode.ShouldBe(0);
+        result.Output.EndsWith("[Apple;Apricot;Spectre Console]");
+    }
+}
+```
+
 ## Testing console behaviour
 
  `TestConsole` and `TestConsoleInput` are testable implementations of `IAnsiConsole` and `IAnsiConsoleInput`, allowing you fine-grain control over testing console output and interactivity.

src/Spectre.Console.Testing/Cli/CommandAppTester.cs

@@ -8,6 +8,11 @@ public sealed class CommandAppTester
     private Action<CommandApp>? _appConfiguration;
     private Action<IConfigurator>? _configuration;
 
+    /// <summary>
+    /// Gets the test console used by both the CommandAppTester and CommandApp.
+    /// </summary>
+    public TestConsole Console { get; }
+
     /// <summary>
     /// Gets or sets the Registrar to use in the CommandApp.
     /// </summary>
@@ -23,10 +28,15 @@ public sealed class CommandAppTester
     /// </summary>
     /// <param name="registrar">The registrar.</param>
     /// <param name="settings">The settings.</param>
-    public CommandAppTester(ITypeRegistrar? registrar = null, CommandAppTesterSettings? settings = null)
+    /// <param name="console">The test console that overrides the default one.</param>
+    public CommandAppTester(
+        ITypeRegistrar? registrar = null,
+        CommandAppTesterSettings? settings = null,
+        TestConsole? console = null)
     {
         Registrar = registrar;
         TestSettings = settings ?? new CommandAppTesterSettings();
+        Console = console ?? new TestConsole().Width(int.MaxValue);
     }
 
     /// <summary>
@@ -36,6 +46,7 @@ public sealed class CommandAppTester
     public CommandAppTester(CommandAppTesterSettings settings)
     {
         TestSettings = settings;
+        Console = new TestConsole().Width(int.MaxValue);
     }
 
     /// <summary>
@@ -85,25 +96,23 @@ public sealed class CommandAppTester
     public CommandAppFailure RunAndCatch<T>(params string[] args)
         where T : Exception
     {
-        var console = new TestConsole().Width(int.MaxValue);
-
         try
         {
-            Run(args, console, c => c.PropagateExceptions());
+            Run(args, Console, c => c.PropagateExceptions());
             throw new InvalidOperationException("Expected an exception to be thrown, but there was none.");
         }
         catch (T ex)
         {
             if (ex is CommandAppException commandAppException && commandAppException.Pretty != null)
             {
-                console.Write(commandAppException.Pretty);
+                Console.Write(commandAppException.Pretty);
             }
             else
             {
-                console.WriteLine(ex.Message);
+                Console.WriteLine(ex.Message);
             }
 
-            return new CommandAppFailure(ex, console.Output);
+            return new CommandAppFailure(ex, Console.Output);
         }
         catch (Exception ex)
         {
@@ -120,8 +129,7 @@ public sealed class CommandAppTester
     /// <returns>The result.</returns>
     public CommandAppResult Run(params string[] args)
     {
-        var console = new TestConsole().Width(int.MaxValue);
+        return Run(args, Console);
-        return Run(args, console);
     }
 
     private CommandAppResult Run(string[] args, TestConsole console, Action<IConfigurator>? config = null)
@@ -164,8 +172,7 @@ public sealed class CommandAppTester
     /// <returns>The result.</returns>
     public async Task<CommandAppResult> RunAsync(params string[] args)
     {
-        var console = new TestConsole().Width(int.MaxValue);
+        return await RunAsync(args, Console);
-        return await RunAsync(args, console);
     }
 
     private async Task<CommandAppResult> RunAsync(string[] args, TestConsole console, Action<IConfigurator>? config = null)

src/Tests/Spectre.Console.Cli.Tests/Unit/Testing/CommandAppTesterTests.cs

@@ -44,4 +44,40 @@ public sealed class CommandAppTesterTests
         // Then
         result.Output.ShouldBe(expected);
     }
+
+    [Fact]
+    public void DefaultCtor_WithoutParameters_CreatesDefaultConsole()
+    {
+        // Given, When
+        CommandAppTester app = new();
+
+        // Then
+        app.Console.ShouldNotBeNull();
+        app.Console.Profile.Width.ShouldBe(int.MaxValue);
+    }
+
+    [Fact]
+    public void DefaultCtor_WithCustomConsole_UsesProvidedInstance()
+    {
+        // Given
+        TestConsole console = new();
+
+        // When
+        CommandAppTester app = new(null, new CommandAppTesterSettings(), console);
+
+        // Then
+        app.Console.ShouldNotBeNull();
+        app.Console.ShouldBeSameAs(console);
+    }
+
+    [Fact]
+    public void Ctor_WithSettings_CreatesDefaultConsole()
+    {
+        // Given, When
+        CommandAppTester app = new(new CommandAppTesterSettings());
+
+        // Then
+        app.Console.ShouldNotBeNull();
+        app.Console.Profile.Width.ShouldBe(int.MaxValue);
+    }
 }

src/Tests/Spectre.Console.Cli.Tests/Unit/Testing/InteractiveCommandTests.cs

@@ -0,0 +1,80 @@
+namespace Spectre.Console.Cli.Tests.Unit.Testing;
+
+public sealed class InteractiveCommandTests
+{
+    private sealed class InteractiveCommand : Command
+    {
+        private readonly IAnsiConsole _console;
+
+        public InteractiveCommand(IAnsiConsole console)
+        {
+            _console = console;
+        }
+
+        public override int Execute(CommandContext context)
+        {
+            var fruits = _console.Prompt(
+                new MultiSelectionPrompt<string>()
+                    .Title("What are your [green]favorite fruits[/]?")
+                    .NotRequired() // Not required to have a favorite fruit
+                    .PageSize(10)
+                    .MoreChoicesText("[grey](Move up and down to reveal more fruits)[/]")
+                    .InstructionsText(
+                        "[grey](Press [blue]<space>[/] to toggle a fruit, " +
+                        "[green]<enter>[/] to accept)[/]")
+                    .AddChoices(new[] {
+                        "Apple", "Apricot", "Avocado",
+                        "Banana", "Blackcurrant", "Blueberry",
+                        "Cherry", "Cloudberry", "Coconut",
+                    }));
+
+            var fruit = _console.Prompt(
+                new SelectionPrompt<string>()
+                    .Title("What's your [green]favorite fruit[/]?")
+                    .PageSize(10)
+                    .MoreChoicesText("[grey](Move up and down to reveal more fruits)[/]")
+                    .AddChoices(new[] {
+                        "Apple", "Apricot", "Avocado",
+                        "Banana", "Blackcurrant", "Blueberry",
+                        "Cherry", "Cloudberry", "Cocunut",
+                    }));
+
+            var name = _console.Ask<string>("What's your name?");
+
+            _console.WriteLine($"[{string.Join(',', fruits)};{fruit};{name}]");
+
+            return 0;
+        }
+    }
+
+    [Fact]
+    public void InteractiveCommand_WithMockedUserInputs_ProducesExpectedOutput()
+    {
+        // Given
+        TestConsole console = new();
+        console.Interactive();
+
+        // Your mocked inputs must always end with "Enter" for each prompt!
+
+        // Multi selection prompt: Choose first option
+        console.Input.PushKey(ConsoleKey.Spacebar);
+        console.Input.PushKey(ConsoleKey.Enter);
+
+        // Selection prompt: Choose second option
+        console.Input.PushKey(ConsoleKey.DownArrow);
+        console.Input.PushKey(ConsoleKey.Enter);
+
+        // Ask text prompt: Enter name
+        console.Input.PushTextWithEnter("Spectre Console");
+
+        var app = new CommandAppTester(null, new CommandAppTesterSettings(), console);
+        app.SetDefaultCommand<InteractiveCommand>();
+
+        // When
+        var result = app.Run();
+
+        // Then
+        result.ExitCode.ShouldBe(0);
+        result.Output.EndsWith("[Apple;Apricot;Spectre Console]");
+    }
+}