Move Spectre.Console.Cli to it's own package

src/Spectre.Console.Cli/CommandOfT.cs

@@ -0,0 +1,48 @@
+namespace Spectre.Console.Cli;
+
+/// <summary>
+/// Base class for a command.
+/// </summary>
+/// <typeparam name="TSettings">The settings type.</typeparam>
+/// <seealso cref="AsyncCommand{TSettings}"/>
+public abstract class Command<TSettings> : ICommand<TSettings>
+    where TSettings : CommandSettings
+{
+    /// <summary>
+    /// Validates the specified settings and remaining arguments.
+    /// </summary>
+    /// <param name="context">The command context.</param>
+    /// <param name="settings">The settings.</param>
+    /// <returns>The validation result.</returns>
+    public virtual ValidationResult Validate([NotNull] CommandContext context, [NotNull] TSettings settings)
+    {
+        return ValidationResult.Success();
+    }
+
+    /// <summary>
+    /// Executes the command.
+    /// </summary>
+    /// <param name="context">The command context.</param>
+    /// <param name="settings">The settings.</param>
+    /// <returns>An integer indicating whether or not the command executed successfully.</returns>
+    public abstract int Execute([NotNull] CommandContext context, [NotNull] TSettings settings);
+
+    /// <inheritdoc/>
+    ValidationResult ICommand.Validate(CommandContext context, CommandSettings settings)
+    {
+        return Validate(context, (TSettings)settings);
+    }
+
+    /// <inheritdoc/>
+    Task<int> ICommand.Execute(CommandContext context, CommandSettings settings)
+    {
+        Debug.Assert(settings is TSettings, "Command settings is of unexpected type.");
+        return Task.FromResult(Execute(context, (TSettings)settings));
+    }
+
+    /// <inheritdoc/>
+    Task<int> ICommand<TSettings>.Execute(CommandContext context, TSettings settings)
+    {
+        return Task.FromResult(Execute(context, settings));
+    }
+}