A standalone single-file Node.js script that installs dependencies locally in dotfiles

node-script-with-dependencies.js

/**
 * This small function allows you to distribute your script as a single file, without
 * requiring a separate package.json. When running a script through a node, the dependencies
 * that are installed will not affect neighboring scripts or global packages.
 * @summary Installs dependencies in the local dotfiles folder
 */
const installDependencies = dependencies => {
    const fs = require('fs');
    const dependenciesPath = './.npm-' + __filename.match(/[^\\/]+$/)[0];
    fs.existsSync(dependenciesPath) || fs.mkdirSync(dependenciesPath);
    const packageFile = dependenciesPath + '/package.json';
    const oldPackage = fs.existsSync(packageFile) && JSON.parse(fs.readFileSync(packageFile));
    if (JSON.stringify(oldPackage.dependencies) !== JSON.stringify(dependencies)) {
        fs.writeFileSync(packageFile, JSON.stringify({ dependencies }, null, '  '));    
        require('child_process').execSync('npm i', { stdio: 'inherit', cwd: dependenciesPath });
    }
    process.env.NODE_PATH = dependenciesPath + '/node_modules';
    require('module').Module._initPaths();
};

// A simple usage example:

installDependencies({
    'lodash': '^4.0.0',
    'moment': '^2.0.0'
});

const { sortBy } = require('lodash');
const moment = require('moment');

const dates = sortBy(
    ['2000-12-31','2000-01-01'],
    s => moment(s).valueOf());

console.log(dates);