Move dependencies to devDependencies

index.js

#!/usr/bin/env node

const path = require('path');
const fs = require('fs');
const pkg = require(path.join(process.cwd(), 'package.json'));

const whitelist = ['babel-polyfill', '@babel/polyfill'];
const devDependencyPatterns = [
  '@nerdwallet/nw-app-build',
  /babel/,
  /eslint/,
  'chai',
  /mocha/,
  'istanbul',
  'nock',
  'react-addons-test-utils',
  'redux-mock-store',
  /-loader/,
  /jsdom/,
  /webpack/,
];

const isDevDependency = dependency => {
  return devDependencyPatterns.some(pattern => {
    return typeof pattern === 'string' ? dependency.includes(pattern) : pattern.test(dependency);
  });
};

const updatedDependencies = [];

Object.keys(pkg.dependencies).forEach(dependency => {
  if (isDevDependency(dependency) && !whitelist.includes(dependency)) {
    pkg.devDependencies[dependency] = pkg.dependencies[dependency];
    updatedDependencies.push(dependency);
  }
});

updatedDependencies.forEach(dependency => {
  delete pkg.dependencies[dependency];
});

if (updatedDependencies.length) {
  console.log(`Moving the following to devDependencies: \n${updatedDependencies.join('\n')}`);
} else {
  console.log('All devDependencies already in the correct location.');
}

fs.writeFileSync('package.json', JSON.stringify(pkg, null, 2));

package.json

{
  "name": "dependencies-to-devDependencies",
  "version": "0.0.0",
  "bin": "./index.js"
}