Minimalistic embeddable argument parser in node.js without any dependencies

cli-arg-parser.js

#!/usr/bin/env node

const APP_NAME = 'CliApp';
const APP_VER = '1.0.0';

class CliArgParser {
    constructor() {
        this.argv = process.argv.slice(2);
        this.args = this.map();
    }
    kv(arg, weed) {
        let key = arg.substr(0, arg.indexOf(weed)).trim().replace(/^-+/, '');
        let value = arg.substr(arg.indexOf(weed) + 1, arg.length).trim();
        let pair = {};
        pair[key] = value;
        return pair;
    }
    map() {
        let map = { _: [] };
        for (let i = 0; i < this.argv.length; i++) {
            let arg = this.argv[i];
            if (arg[0] == '-') {
                let pair = {};
                if (arg.indexOf('=') >= 0) {
                    pair = this.kv(arg, '=');
                } else if (arg.indexOf('=') >= 0) {
                    pair = this.kv(arg, ':');
                } else {
                    let key = arg.trim().replace(/^-+/, '');
                    if (!!key) {
                        pair[key] = true;
                    }
                }
                map = { ...pair, ...map };
            } else {
                map._.push(arg);
            }
        }
        return map;
    }
}

const cli = new CliArgParser();
// console.log(cli.argv, '|', cli.args);

if ('h' in cli.args || 'help' in cli.args) {
    console.log(`${APP_NAME}
 Syntax:
  cliapp -h
  cliapp -v

 Options:
  -h  --help        Show help menu
  -v  --version     Show version
    `);
} else if ('v' in cli.args || 'version' in cli.args) {
    console.log(`Version ${APP_VER}`);
} else {
    console.log(`App initiated`);
    // Put your code here
}