@feugene/mu/src/internal/base/baseKeys.ts

Helpful TS utilities without dependencies

/** Used for built-in method references. */
import isPrototype from '~/is/isPrototype'

const objectProto = Object.prototype

/** Used to check objects for own properties. */
const hasOwnProperty = objectProto.hasOwnProperty

const nativeKeys = (argument: any) => Object.keys(new Object(argument))

/**
 * The base implementation of `keys` which doesn't treat sparse arrays as dense.
 *
 * @private
 * @param {Object} object The object to query.
 * @returns {string[]} Returns the array of property names.
 */
export default function baseKeys(object: Object): string[] {
  if (!isPrototype(object)) {
    return nativeKeys(object)
  }
  const result = []
  let key

  for (key in new Object(object)) {
    if (hasOwnProperty.call(object, key) && key !== 'constructor') {
      result.push(key)
    }
  }
  return result
}