@thefarce/commando

Commando

Commando is a powerful node module for creating command-line interfaces (CLIs) with ease and flexibility. It provides a functional interface for defining commands, options, and arguments, enabling developers to build complex CLI tools quickly.

LLM Trainer

If you are using an LLM such as ChatGPT to help you write code, feed it the llm-trainer.md file as a seed. It has a bunch of content generated specifically to help LLMs give you good advice about using this module.

Installation

npm install @thefarce/commando

Basic Usage

Creating a Simple Command

// Import the necessary functions
const { program } = require('@thefarce/commando');

// Create a simple program that prints a message
const helloWorld = program(() => {
  console.log('Hello, World!');
});

// Execute the program
helloWorld();

Handling Options

Adding Options to a Program

const { program, option } = require('@thefarce/commando');

const greet = program(
  option('-n --name {String}', 'Your name', 'Specifies the name to greet.'),
  (context) => {
    const name = context.getOption('name') || 'World';
    console.log(`Hello, ${name}!`);
  }
);

greet('--name', 'Alice');

Using Arguments

Defining and Accessing Arguments

const { program, argument } = require('@thefarce/commando');

const add = program(
  argument('num1', 'First number'),
  argument('num2', 'Second number'),
  ($prog) => {
    const num1 = parseInt($prog.getArgument('num1'), 10);
    const num2 = parseInt($prog.getArgument('num2'), 10);
    console.log(`${num1} + ${num2} = ${num1 + num2}`);
  }
);

add('5', '7');

Subcommands

Implementing Subcommands

const { program, subcommand } = require('@thefarce/commando');

const sub = program(
  () => console.log('Executing subcommand...')
);

const main = program(
  subcommand('sub', sub, 'A subcommand example')
);

main('sub');

Advanced Options Handling

Options with Default Values and Validation

const { program, option } = require('@thefarce/commando');

const serve = program(
  option('-p --port {Number}', 'Server port', 'Specifies the port number for the server.', 3000),
  (context) => {
    const port = context.getOption('port');
    console.log(`Server starting on port ${port}...`);
  }
);

serve('--port', '8080');

Combining Options and Arguments

Creating a More Complex CLI Tool

const { program, option, argument } = require('@thefarce/commando');

const fileOperation = program(
  option('-o --operation {String}', 'Operation type', 'Specifies the operation to perform on the file.', 'read'),
  argument('file', 'File path', 'Specifies the path to the file.'),
  ($prog) => {
    const operation = $prog.getOption('operation');
    const file = $prog.getArgument('file');
    console.log(`Performing '${operation}' on '${file}'...`);
  }
);

fileOperation('--operation', 'write', '/path/to/file.txt');

Error Handling

Basic Error Handling in Commands

const { program } = require('@thefarce/commando');

const riskyCommand = program(
  () => {
    try {
      // Simulate an operation that might fail
      throw new Error('An unexpected error occurred!');
    } catch (error) {
      console.error(`Error: ${error.message}`);
    }
  }
);

riskyCommand();

Nested Subcommands

Using Nested Subcommands for Complex CLI Applications

const { program, subcommand } = require('@thefarce/commando');

const nestedSubcommand = program(
  () => console.log('Executing nested subcommand...')
);

const parentSubcommand = program(
  subcommand('nested', nestedSubcommand, 'A nested subcommand')
);

const mainProgram = program(
  subcommand('parent', parentSubcommand, 'A parent subcommand')
);

mainProgram('parent', 'nested');