lovacli

LovaCLI

node.js CLI boilerplate:

• On top of Caporal.js
• ES 2017 async/await ready
• Optional Mongoose or Sequelize as MongoDB, MySQL, PostgreSQL ORM/ODM
• Winston as logger
• OOP for commands and modules
• ❤️

Installation

npm install lovacli --save

Usage

Sample application

#!/usr/bin/env node
 
const {Program,Command,LovaClass} = require('lovacli');
const path = require('path');
 
let program = new Program({
        "name": "Sample CLI Application",
        "debug": true,
        "version": "1.0.0",
        "paths": {
            "commands": path.join(__dirname, "commands")
        }
    });
 
program.init();

Sample command class

Save it as test.js in commands/ path. It will be ready to be executed as node index.js test

const { Program, Command, LovaClass } = require('lovacli');
 
class Handler extends Command {
    /**
     * Set up command, description, options, arguments
     * Optional. You can ommit it if you don't need any specific settings
     * Can be async or sync.
     */
    async setup(progCommand) {
        progCommand.argument('[app]', 'App to deploy', /^myapp|their-app$/);
        progCommand.option('--tail <lines>', 'Tail <lines> lines of logs after deploy', this.prog.INT);
        progCommand.description('Command description');
        /// read more about Caporal.js's prog methods 
        /// (options, args, validation) 
        /// here: https://github.com/mattallty/Caporal.js#examples
    }
 
    /**
     * Handle command
     * Can be async or sync.
     */
    async handle(args, options, logger) {
        // handle() runs on command execution
        // as we probably don't need db for every run, lets initialize it on demand here
        let db = await this.db.init();
        // both logger and this.logger works for accessing Winston's methods
        // logger.info('info');
        // this.logger.info(eventTypes);
 
        // mongoose models        
        // let eventTypes = await db.EventType.find().exec();
        // this.logger.info(eventTypes);
        // ...
 
        // sequelize models
        // let rigs = await db.Rig.findAll();
        // this.logger.info(rigs);
        // ...
 
        logger.info('Done.');
 
        this.program.exit();
    }
};
 
module.exports = Handler;

API

Program

constructor(options) : Program

Default options are:

{
    "name": "LovaCLISampleApp",
    "debug": true,
    "version": "1.0.0",
    "paths": {
        "models": path.join(__dirname, "../app/models"),
        "commands": path.join(__dirname, "../app/commands"),
        "tests": path.join(__dirname, "../app/tests")
    }
}

You can extend them, passing options object, const program = new Program({name: "Better name", debug: false});

async loadCommand(filename) : Command

Loads command class from filename, create entity of it and initialize it. Assigns name(extract it from filename, so for testfile.js it will be 'testfile'), assigns description(optional help message, you can specify it with description method, getter or property of command class), and calls setup methods.

async init(handleImmediate = true)

• Loads all commands from options.paths.commands paths and initializes them.
• Executes application, if handleImmediate = true, defaults = true

async handle()

Executes application. Use it, after you initialize application with init(false)

program.init(false).then(()=>{
    program.handle();
});
### or
await program.init(false);
await program.handle();

async execute(name, args = [], options = {})

Executes command by name. Use it if you need to call some command from another command's handle.

exit(e = null)

Exits application. Logs error if it's passed

Command

Need to be extended in order to use. Load and initialize extended classes using program.init() or program.loadCommand(). Command is also EventEmitter, so feel free to use native EventEmmiter methods: https://nodejs.org/api/events.html#events_class_eventemitter

 
const { Program, Command, LovaClass } = require('lovacli');
 
class Handler extends Command {
    /**
     * Optional
     */
    async setup(progCommand) {
    }
 
    /**
     * Required
     */
    async handle(args, options, logger) {
    }
};
 
module.exports = Handler;
 

async setup(progCommand)

setup(progCommand)

Optional to extend. Can be async or sync. Set up command, description, options, arguments.

async setup(progCommand) {
    progCommand.argument('[app]', 'App to deploy', /^myapp|their-app$/);
    progCommand.option('--tail <lines>', 'Tail <lines> lines of logs after deploy', this.prog.INT);
    progCommand.description('Command description');
    /// read more about Caporal.js's prog methods 
    /// (options, args, validation) 
    /// here: https://github.com/mattallty/Caporal.js#examples
}

async handle(args, options, logger)

handle(args, options, logger)

Required. Can be async or sync. Run code executed for this command.

async name() : String

Returns command name.

.logger : Winston object

    async handle(args, options, logger) {
        this.logger.info('Information');
        this.logger.debug(object);
        this.logger.error(object);
    }

.program : Parent Program instance

async handle(args, options, logger) {
    this.program.execute('othercommand', [1,'2'], {option: 'value'});
    this.program.exit(new Error('Hmmm!'));
}

How to?

Take application name, version and description from package.json?

It may be a good idea to store program's description and version name in one place. It's already in package.json, so why don't to use that values?

#!/usr/bin/env node
 
const {Program,Command,LovaClass} = require('lovacli');
const path = require('path');
 
const pjson = require(path.join(__dirname, 'package.json'));
 
let program = new Program({
        "name": pjson.description || pjson.name,
        "version": pjson.version,
        "debug": true,
        "paths": {
            "commands": path.join(__dirname, "commands")
        }
    });
 
program.init();

Execute another command from command's handle

There's program.execute method:

### somecommand.js
const { Program, Command, LovaClass } = require('lovacli');
 
class Handler extends Command {
    async handle(args, options, logger) {
    }
};
 
module.exports = Handler;

### test.js
const { Program, Command, LovaClass } = require('lovacli');
 
class Handler extends Command {
    async handle(args, options, logger) {
        await this.program.execute('somecommand', ['argument1', 'argument2'], {option: 'value'});
    }
};
 
module.exports = Handler;