evan-choi / command-line-api-generator

System.CommandLine.SourceGenerator

Enhance your .NET CLI applications with dynamic command-line interface (CLI) capabilities using System.CommandLine.SourceGenerator. This package leverages the power of source generators to automatically create robust RootCommand code, simplifying the development of complex CLI tools.

Getting Started

To incorporate System.CommandLine.SourceGenerator into your project, simply install the package via NuGet:

Install-Package Evan.System.CommandLine.SourceGenerator
Install-Package Evan.System.CommandLine.SourceGenerator.Common

Defining Commands

[RootCommand(Handler = typeof(AppCommandHandler))]
class AppCommand
{
    [Option("verbose", IsRequired = false, Description = "Set output to verbose messages.")]
    public bool Verbose { get; set; }

    [Command("config")]
    class Config
    {
        [Command("get", Handler = typeof(ConfigGetCommandHandler))]
        class GetCommand
        {
            [Argument("key", Description = "The configuration key to retrieve.")]
            public string Key { get; set; }
        }
    }
}

Implementing Command Handlers

Implement handlers for your commands to define the logic executed when commands are invoked:

class AppCommandHandler : ICommandHandler<AppCommand>
{
    public Task<int> InvokeAsync(AppCommand command)
    {
        // Implementation logic here...
    }
}

class ConfigGetCommandHandler : ICommandHandler<AppCommand.Config.GetCommand>
{
    public Task<int> InvokeAsync(AppCommand.Config.GetCommand command)
    {
        // Implementation logic here...
    }
}

Execution

Bootstrap and run your application by invoking the command handler from your program's entry point:

static async Task Main(string[] args)
{
    var command = AppCommandFactory.Create();
    Environment.ExitCode = await command.InvokeAsync(args);
}