index.js

#!/usr/bin/env node

const run = require('child_process').execSync;
const writeFile = require('fs').writeFileSync;

const log = message => console.log('>', message);

log('Installing lint-staged for capturing changed files...');
log('Installing prettier for automatic code formatting...');
log('Installing husky for git hooks...');

try {
  run('npm install --save-dev --save-exact prettier@1.11.1 husky@0.14.3 lint-staged@6.0.0');
  log('Packages are installed!');
} catch (err) {
  log('Could not install packages!');
  return 0;
}

log('Adding automated styling config to package.json...');

const packageConfig = require(process.cwd() + '/package.json');
const newConfig = Object.assign(packageConfig, {
  prettier: {
    printWidth: 80,
    tabWidth: 2,
    useTabs: false,
    semi: true,
    singleQuote: true,
    trailingComma: "none",
    bracketSpacing: true,
    jsxBracketSameLine: true,
    requirePragma: false
  },
  "lint-staged": {
    "*.js": [
      "./node_modules/.bin/prettier --write",
      "git add"
    ]
  },
  scripts: Object.assign(packageConfig.scripts, {
    precommit: "lint-staged",
    postcommit: "git reset"
  })
});

writeFile(process.cwd() + '/package.json', JSON.stringify(newConfig, 2, 2));

log('package.json was changed!');