cli-kit

cli-kit

A command line application toolkit for Node.js.

Features

• Command line parsing
• Support for dynamic command hierarchies
• Auto-generated help
• CLI template engine
• External CLI extensions
• Client and server for remote CLI session such as xterm.js
• Automatic Node.js version enforcement

Installation

npm install cli-kit --save

Usage

import CLI from 'cli-kit';

(async () => {
	const { argv, _ } = await new CLI({
		options: {
			'-f, --force': 'use the force',
			'--timeout [value]': {
				desc: 'the timeout duration',
				type: 'int'
			}
		}
	}).exec();

	console.log('options:', argv);
	console.log('args:', _);
})();

Architecture

In cli-kit, commands and options are grouped into "contexts". The main CLI instance defines the "global context". Each command defines a new context. Each context can have its own commands, options, and arguments. What you end up with is a hierarchy of contexts.

When cli-kit parses the command line arguments, it will check each argument against the global context to see if the argument can be identified as a known command, option, or argument. If it finds a command, it adds the command's context to a stack and re-parses any unidentified arguments.

This allows you to create deep and dynamic hierarchies of commands, options, and arguments.

Pseudo-Terminal Support

cli-kit extensions can be native binary executables or other Node.js scripts. When the extension is a native executable, then it is executed using Node's spawn(). Note that spawned child processes do not have a TTY and thus things like prompting will not work.

API

class CLI

A CLI intance defines a global context for which you add commands, options, and arguments.

Extends Context > HookEmitter.

constuctor(opts)

• opts : Object (optional)

  Various options to initialize the CLI instance.

Example

const cli = new CLI({
	// An array of argument definitions. They are parsed in the order they are defined.
	args: [
		// An argument can be as simple as its name. Wrapping the name with `<` and `>` signifies
		// that the argument is required.
		'<arg1>',

		// To define an optional arguemnt, you can use `[` and `]`.
		'[arg2]',

		// Or simply omit the brackets
		'arg3',

		// For more options, you can specify an argument descriptor
		{
			// The argument name. Follows the same rules as above.
			name: 'arg4',

			// The argument's description to show in the help output.
			desc: undefined,

			// When `true`, hides the argument from usage string in the help output.
			hidden: false,

			// When `true`, captures all subsequent argument values into an array
			multiple: false,

			// Overrides the brackets and forces the argument to be required or optional.
			required: false,

			// There are several built-in types. See the "types" section below for more info.
			type: 'string'
		},

		// Adding `...` will capture all subsequent argument values into an array
		'arg4...'
	],

	// Global flag to camel case property names derived from multi-word options/arguments.
	// Defaults to true, can be overwritten by the option/argument.
	camelCase: true,

	// An object of command names to command descriptors.
	commands: {
		'some-command': {
			// The action to perform when the command is parsed.
			action({ argv, _ }) {
				console.log('options:', argv);
				console.log('args:', _);
			},

			// An array of alternate command names.
			aliases: [ 'another-command' ],

			// Command specific args. See `args` section above.
			args: [],

			// When `true`, camel case all option and argument names in the `argv` result.
			camelCase: true,

			// An object of subcommand names to subcommand descriptors.
			commands: {},

			// The command description.
			desc: undefined,

			// When `true`, hides the command from the help output.
			hidden: false,

			// An object of option formats to option descriptors. See the `options` section below.
			options: {},

			// The command name to display in the help output. Defaults to the command name.
			title: undefined
		}
	},

	// The default command `exec()` should run if no command was found during parsing.
	// If `help` is `true` and no default command is specified, it will default to displaying the
	// help screen. If you want help, but do not want to default to the help command, then set the
	// `defaultCommand` to `null`.
	defaultCommand: undefined,

	// The CLI description to print on the help screen between the usage and commands/options/args.
	desc: undefined,

	// Adds the `-h, --help` to the global flags and enables the auto-generated help screen.
	// Defaults to `true`.
	help: true,

	// The exit code to return when the help screen is displayed. This is useful if you want to
	// force the program to exit if `--help` is specified and the user is chaining commands together
	// or after displaying the help screen and prevent further execution in the CLI's promise chain.
	helpExitCode: undefined,

	// The name of the program used by the help screen to display the command's usage.
	// Defaults to "program".
	name: 'program',

	// An object of option formats to option descriptors or an array of sorted group names and
	// objects of option formats to option descriptors.
	options: {
		//
	},

	// The title for the top-level (or "Global") context. This title is displayed on the help screen
	// when displaying the list of options.
	title: 'Global',

	// When set, it will automatically wire up the `-v, --version` option. Upon calling with your
	// program with `--version`, it will display the version and exit with a success (zero) exit
	// code.
	version: null
});

exec(args)

Parses the command line args and executes a command, if found.

• args : Array<String> (optional)

  An array of arguments. Each argument is expected to be a string.

  Defaults to process.argv.slice(2).

Returns a Promise that resolves an Arguments object. This object will contain the parsed options in argv and arguments in _.

Example

cli.exec()
	.then(({ argv, _ }) => {
		console.log('options:', argv);
		console.log('args:', _);
	});

class Context

Base class for CLI and Command classes.

Extends HookEmitter.

argument(arg)

Adds an argument to a CLI or Command.

• arg : Argument, Object, or String.

  An argument descriptor. Either an Argument instance or an Object to pass into a Argument constructor.

  An argument requires a name.

Returns a reference to the CLI or Command.

Example

// define a non-required argument "foo"
cli.argument('foo');

// define a non-required argument "wiz"
cli.argument('[wiz]');

// define a required argument "pow"
cli.argument('<pow>');

cli.argument({
	name: 'bar',
	type: 'int'
});

cli.argument(new Argument('baz'));

command(cmd, opts)

Adds a command to a CLI or Command.

TODO

option(optOrFormat, group, params)

Adds an option or group of options to a CLI or Command.

TODO

Who Uses cli-kit?

• Axway

License

MIT

Changelog

v1.16.0 (Apr 21, 2022)

• feat: Add support for extension CLIs with multiple exported entrypoints that do not use cli-kit. Fixes #97.
• chore: Updated dependencies.