install-prettier-precommit.js

const prettierOptions = '--single-quote --jsx-bracket-same-line --trailing-comma es5';

const generateBlocks = (pkg, keys) => {
  keys.forEach(key => {
    if (!pkg[key]) pkg[key] = {};
  });
};

const _message = message => {
  console.log('-> ', message);
};

try {
  let pkg = require('./package.json');
  let fs = require('fs');
  let exec = require('child_process').exec;
  let isYarn = fs.existsSync('./yarn.lock');
  let args = process.argv.slice(2);
  if (!isYarn) {
    isYarn = args.indexOf('--npm') === -1;
  }
  generateBlocks(pkg, ['devDependencies', 'scripts', 'lint-staged']);
  _message('Configuring pre-commit ...');
  pkg.devDependencies['lint-staged'] = '*';
  pkg.devDependencies['husky'] = '*';
  pkg.devDependencies['prettier'] = '*';
  pkg.scripts.jsformat = `prettier --write ${prettierOptions} `;
  pkg.scripts.precommit = 'lint-staged';
  pkg['lint-staged']['*.js'] = [`prettier --write ${prettierOptions}`, 'git add'];
  _message('Writing package.json ...');
  fs.writeFileSync('./package.json', JSON.stringify(pkg, null, 2));

  if (isYarn) {
    _message('Installing dependencies using YARN...');
    exec('yarn', { shell: '/bin/sh' }, (err, stdout, stderr) => {
      console.log('Installed the dependencies', stdout, stderr);
    });
  } else {
    _message('Installing dependencies using NPM...');
    exec(
      'npm install --only=dev',
      { shell: '/bin/sh' },
      (err, stdout, stderr) => {
        console.log('Installed the dependencies', stdout, stderr);
      }
    );
  }
} catch (err) {
  _message('Error occured :: ', err.toString());
}