clipanion

What is clipanion?

The clipanion npm package is a powerful library for building command-line interfaces (CLIs) in Node.js. It provides a rich set of features for defining commands, parsing arguments, validating input, and generating help messages.

What are clipanion's main functionalities?

Command Definition

Clipanion allows you to define commands as classes, which can then be registered with a CLI instance. Each command can have its own execute method that contains the logic to be run when the command is invoked.

class MyCommand extends Command {
  execute() {
    console.log('Command executed!');
  }
}

const cli = new Cli();
cli.register(MyCommand);
cli.runExit(process.argv.slice(2));

Argument Parsing

Clipanion provides a declarative way to define command arguments using class properties. These arguments are automatically parsed and made available within the command's execute method.

class MyCommand extends Command {
  myArgument = Option.String();

  execute() {
    console.log(`Argument value: ${this.myArgument}`);
  }
}

const cli = new Cli();
cli.register(MyCommand);
cli.runExit(process.argv.slice(2));

Input Validation

Clipanion includes built-in validation for command arguments. You can specify whether an argument is required, and Clipanion will automatically enforce this when the command is run.

class MyCommand extends Command {
  myArgument = Option.String({ required: true });

  execute() {
    console.log(`Argument value: ${this.myArgument}`);
  }
}

const cli = new Cli();
cli.register(MyCommand);
cli.runExit(process.argv.slice(2));

Help Generation

Clipanion can automatically generate help messages for your commands. You can provide descriptions, detailed information, and usage examples that will be displayed when the help command is invoked.

class MyCommand extends Command {
  static usage = Command.Usage({
    description: 'My command description',
    details: 'Detailed information about my command',
    examples: [['Example usage', 'my-cli my-command']]
  });

  execute() {
    console.log('Command executed!');
  }
}

const cli = new Cli();
cli.register(MyCommand);
cli.runExit(process.argv.slice(2));

Other packages similar to clipanion

commander

Commander is one of the most popular CLI frameworks for Node.js. It offers a simple and expressive API for creating command-line applications. Compared to clipanion, commander has a more imperative style and does not use classes to define commands.

yargs

Yargs is another widely-used library for building CLIs. It provides a fluent interface for defining options and commands. Yargs focuses on parsing command-line arguments and generating help text, similar to clipanion, but with a different API design.

inquirer

Inquirer.js is a library for creating interactive command-line user interfaces. It is often used in conjunction with other CLI libraries to gather user input through a series of questions. While it does not handle command definition or parsing like clipanion, it complements these features with its interactive prompts.