Get a bunch of dependencies from multiple package.json formated for npm install command

get-package-dependencies.js

#!/usr/bin/env node
const fs = require('fs');
const path = require('path');

const args = process.argv.slice(2);

const targetDependencies = args.filter(arg => arg.includes('ependencies')).length
  ? args.filter(arg => arg.includes('ependencies'))
  : ['peerDependencies', 'devDependencies', 'dependencies'];
const packageFiles = args.filter(arg => arg.includes('json')).length
  ? args.filter(arg => arg.includes('json'))
  : ['package.json'];


const dependenciesObj = packageFiles
  .map(packageFile => JSON.parse(fs.readFileSync(path.resolve(process.cwd(), packageFile), 'utf8')))
  .map(packageJSON => targetDependencies.map(dependencyType => packageJSON[dependencyType]))
  .reduce((a, b) => a.concat(b))
  .filter(dependencyObj => dependencyObj)
  .reduce((a, cv) => (Object.assign(a, cv)), {});


const dependenciesStr = Object.keys(dependenciesObj)
  .map(dependency => `${dependency}@"${dependenciesObj[dependency]}"`)
  .join(' ');

process.stdout.write(dependenciesStr);