o/src/keyOf.ts

common object helper functions

// o
import { valid } from './util'
import defaults from './defaults'
import find from './find'
import { KeyOfOptions, OObject } from './types'

// default options
const getDefaults = defaults({
  follow: false
})

/**
 * Get the key to the specified value in dot notation
 *
 * @example
 * ```
 * const a = { a: 1, b: { c: 2 } };
 *
 * keyOf(a, 2); // => undefined
 * keyOf(a, 2, {
 *   follow: true,
 * }); // => 'b.c'
 * ```
 *
 * @throws TypeError
 *
 * @since 1.0.0
 * @version 2.0.0
 */
function keyOf (
  obj: OObject,
  value: any,
  options: KeyOfOptions = {}
): string | undefined {
  // extract options
  const {
    follow
  } = getDefaults(options) as KeyOfOptions

  // check if the args specified are the correct type
  if (!valid(obj)) throw new TypeError(`Expected Object, got ${typeof obj} ${obj}`)
  if (typeof follow !== 'boolean') throw new TypeError(`Expected Boolean, got ${typeof follow} ${follow}`)

  // this is just an alias of find so we simply just pass the params
  // to the find function and return its result
  return find(obj, (key, objValue): boolean => objValue === value, {
    follow
  })
}

export default keyOf