Create a flatten object from an any level nested object.

flattenObject.js

/**
 * Creates a flatten object from an any level nested object.
 *
 * @example
 *
 * Create following object:
 *
 * {
 *    'address.city.name': 'São Paulo',
 *    'address.state.name': 'SP',
 *    'address.street.number': 123,
 *    'address.street.name': 'Gustave Rapin',
 * }
 *
 * From this object:
 *
 * {
 *    address: {
 *      city: {
 *        name: 'São Paulo'
 *      },
 *      state: {
 *        name: 'SP'
 *      },
 *      street: {
 *        number: 123,
 *        name: 'Gustave Rapin'
 *      }
 *    }
 * }
 *
 * @param {object} input
 * @param {string} divider
 * @return {object}
 */
export function flattenObject(input, divider = '.') {
  const mapper = {}

  const dive = (name, value) => {
    if (typeof value !== 'object') {
      mapper[name] = value
      return
    }
    Object.keys(value).forEach((key) =>
      dive(`${name}${divider}${key}`, value[key]),
    )
  }

  Object.keys(input).map((k) => dive(k, input[k]))

  return mapper
}