Flattenizer

Functions to flatten and unflatten nested JavaScript objects into a single level.

Installation

npm install flattenizer

Usage

import { flatten, unflatten } from 'flattenizer';

// Flatten a nested object
const nested = {
  name: 'Sean',
  city: 'Kansas City',
  favBreweries: [
    { name: 'Double Shift', favBeer: 'Sister Abbey' },
    { name: 'KC Bier Co', favBeer: 'Helles' }
  ]
};

flatten(nested);
// {
//   name: 'Sean',
//   city: 'Kansas City',
//   'favBreweries.0.name': 'Double Shift',
//   'favBreweries.0.favBeer': 'Sister Abbey',
//   'favBreweries.1.name': 'KC Bier Co',
//   'favBreweries.1.favBeer': 'Helles'
// }

// Unflatten back to nested
const flat = {
  name: 'Sean',
  city: 'Kansas City',
  'favBreweries.0.name': 'Double Shift',
  'favBreweries.0.favBeer': 'Sister Abbey',
  'favBreweries.1.name': 'KC Bier Co',
  'favBreweries.1.favBeer': 'Helles'
};

unflatten(flat);
// {
//   name: 'Sean',
//   city: 'Kansas City',
//   favBreweries: [
//     { name: 'Double Shift', favBeer: 'Sister Abbey' },
//     { name: 'KC Bier Co', favBeer: 'Helles' }
//   ]
// }

API

flatten<A, B>(unflattened: B | null | undefined, delimiter?: string): A | null | undefined

Flattens a nested object into a single-level object with dot-separated keys.

• unflattened - The nested object to flatten
• delimiter - The delimiter to use (default: '.')
• returns - The flattened object, or null/undefined if input is null/undefined

unflatten<A, B>(flattened: A | null | undefined, delimiter?: string): B | null | undefined

Unflattens a flat object with dot-separated keys back into a nested object.

• flattened - The flat object to unflatten
• delimiter - The delimiter to use (default: '.')
• returns - The nested object, or null/undefined if input is null/undefined

Note: Dangerous keys (__proto__, prototype, constructor) are blocked to prevent prototype pollution attacks.

Custom Delimiters

Both functions accept an optional delimiter:

flatten({ a: { b: 1 } }, '|');
// { 'a|b': 1 }

unflatten({ 'a|b': 1 }, '|');
// { a: { b: 1 } }

Development

npm install    # Install dependencies
npm test       # Run tests
npm run build  # Build for production
npm start      # Watch mode

License

MIT