Cliffy - A Framework For Interactive CLIs

Cliffy is a simple, powerful utility for making interactive command line interfaces.

Cliffy is run as a REPL. This allows you to accept multiple commands with one running node process. Cliffy is NOT an argv parser.

Features:

• REPL Style interface
• Simple API
• Can parse negative numbers
• Typed parameters
• Git Style Sub-Commands
• Optional parameters (New in v2)
• Rest parameters (New in v2)
• Options
• Auto generated help
• Typescript Support

Gotchas:

• Options are specified with an @ symbol. Not - or --. This is what allows Cliffy to parse negatives.
• Requires node v6+

Quickstart

Installation:

npm i cliffy # --save if using npm < v5

Usage

import { CLI } from "cliffy";

const cli = new CLI()
    .setDelimiter("-->")
    .addCommand("run", {
        description: "Run somewhere",
        options: [{ label: "quickly", description: "Run quickly" }],
        parameters: ["destination"],
        action: (params, options) => {
            if (options.quickly) {
                console.log(`I ran to ${params.destination} quickly`)
                return;
            }

            console.log(`I ran to ${params.destination}`)
        },
        subcommands: {
            to: {
                description: "Run to a destination",
                parameters: ["destination"],
                action: params => console.log(`I ran to ${params.destination}`)
            },
            from: {
                description: "Run from a destination",
                parameters: ["location"],
                action: params => console.log(`I ran from ${params.location}`)
            }
        }
    })
    .show();

Result:

--> run to nevada
I ran to nevada
--> help

Available commands:

    run [options]  <destination>    Run somewhere

--> help run

Run somewhere

Usage:

    run [options] <destination>

Options:

   @quickly                          Run quickly

Sub-Commands:

    to [options] <destination>       Run to a destination
    from [options] <destination>     Run from a destination

Quoted parameters

Parameters may be quoted using either ' (single) or " (double) quotes. For example the command could be

say "Hello World" 'Lovely Weather'

This would give two parameters of Hello World and Lovely Weather. When inside the quoted parameter, the other type of quotes can be used. This lets JSON be entered for example.

say '{"text": "This is the weather"}'

Will give a parameter of the string, {"text": "This is the weather"} that can then be parsed as JSON.

Autogenerated Help Menu

Cliffy automatically generates a help menu for each command.

To get an overview of all the commands simply type:

help

To get help with a specific command, type help followed by the command.

help ls

This works with subcommands as well

help git pull

Build instructions

1. Clone this repo
2. CD into the repo
3. npm install
4. npm run build

API

new CLI()

Interface:

class CLI {
    constructor(opts: {
        input?: NodeJS.ReadableStream,
        output?: NodeJS.WritableStream,
         /** Set to true to prevent cliffy from displaying help text after entering a blank line. Defaults to false */
        quietBlank?: boolean
    } = {})
}

Usage:

const cli = new CLI(opts)

cli.addCommand(name: string, command: Command): this

Register a command

Takes a name and a command object.

The command name is what the user will enter to execute the command.

The command interface is defined as follows:

interface Command {
    /**
     * The action to perform when its command is called.
     *
     * parameters is a key value store. Where the key is the parameter label,
     * and its value is the value entered by the user.
     *
     * options is a key value store. Key being the option, value being true if the user
     * specified the option, false otherwise.
     */
    action(parameters: any, options: { [key: string]: boolean }): void | Promise<void>;

    /** Optional description for documentation */
    description?: string;

    /** Aliases the command can be accessed from */
    aliases?: string[];

    /**
     * An array of options available to the user.
     * The user specifies an option with an @ symbol i.e. @force
     */
    options?: (Option | string)[];

    /**
     * All the parameters available to the user.
     * See the parameters interface.
     *
     * If a string is passed it is assumed to be string parameter
     */
    parameters?: (Parameter | string)[];

    /** Sub commands of the command. Follows the same interface as Command */
    subcommands?: Commands;
}

export interface Parameter {
    label: string;

    /** The type to convert the provided value to. Can be a custom converter. */
    type?: "boolean" | "number" | "string" | ((val: string) => any);

    /** The parameter is optional */
    optional?: boolean;

    /**
     * The parameter is a rest parameter.
     *
     * If true, the user can pass an indefinite amount of arguments
     * that are put in an array set in this parameter.
     **/
    rest?: boolean;

    /** Optional description for the help menu */
    description?: string;
}

export interface Option {
    label: string;
    description?: string;
}

Example Usage:

cli.addCommand("run", {
    description: "Run somewhere",
    options: [{ option: "fast", description: "Run fast" }],
    parameters: [{ label: "destination" }],
    action: (params, options) => {
        if (options.fast) return console.log(`I ran to ${params.destination} quickly`);
        console.log(`I ran to ${params.destination}`);
    },
    subcommands: {
        to: {
            parameters: [{ label: "destination" }],
            action: params => console.log(`I ran to ${params.destination}`),
        }
        from: {
            parameters: [{ label: "destination" }],
            action: params => console.log(`I ran to ${params.destination}),
        }
    }
});

cli.addCommand(name: string, opts: Action): this

Register a basic command.

This overload allows you to pass the action function directy. Useful for quick commands where parameters, options, and a description may not be needed.

Example usage:

cli.addCommand("speak", () => sayHello("World"));

cli.addCommands(commands: { [name: string]: Command | Action }): this

Register multiple commands at once.

Example usage:

cli.addCommands({
    run: {
        action(params, options) {
            console.log("Running");
        }
    },

    jog: {
        action(params, options) {
            console.log("Jogging");
        }
    },

    walk: {
        action(params, options) {
            console.log("Walking");
        }
    }
});

cli.setDelimiter(delimiter: string): this

Set the CLI delimiter

Defaults to: "$>"

cli.setInfo(info: string): this

Set the CLI info.

Info is meant to give an overview of what the CLI does and how to use it. If it is set it is shown directly under the CLI name.

Defaults to: none

cli.setName(name: string): this

Set the name of the CLI (Shown at the top of the help menu)

Defaults to: none

cli.setVersion(version: string): this

Set the CLI version. Shown beside the CLI name if set.

Defaults to: none

cli.show(): this

Show the CLI.

cli.hide(): this

Hide the cli.

cli.showHelp(): this

Show the main help menu.