sample.ts

import { Cli, Command } from 'mustard-cli';
import { Register, Context, Options } from 'mustard-cli/decorators'
import { PackageManager } from 'mustard-cli/types'

const cli = Cli();

interface ICoreOptions {
  name: string;
  sayHi: boolean;
}

// foo --name linbudu --sayHi
@RegisterCommand()
class CoreCommand extends Command {
  
  @Options()
  commandArgs: ICoreOptions;
  
  run(){
    this.commandArgs.sayHi && this.logger.info(`Hi, ${this.commandArgs.name}!`)
    return 0;
  }
}

// foo create react-app --typescript --manager pnpm
@RegisterCommand("create")
class CreateCommand extends Command {
  // react-app
  @Input(Validator.required().isString())
  input: string;
  
  // true
  @Option()
  typescript: boolean;
  
  // pnpm
  @Option(Validator.custom(this.customManagerValidation))
  manager: PackageManager = this.preferredPackageManager();
  
  constructor(){
    super();
  }
  
  // when there is no returned value, it's regarded as succeed
  customManagerValidation(manager: string){
		if(!['npm', 'yarn', 'pnpm'].includes(manager)){
      return {
        success: false,
        message: `${manager} is not any known manager.`
      }
    }
  }
  
  run(){
    this.spinner().start("Creating your React application...");
    this.writeJson(process.cwd(), 'This is your React project!').then((res)=>{
      this.spinner().end("Success!");
      this.exitManually(0);
    }).catch((err)=>{
      this.log.error(err);
      this.exitManually(1);
    })
  }
  
}

cli.initialize();

cli.useHelp();