Source: isDate/index.js

import requiredArgs from '../_lib/requiredArgs/index'

/**
 * @name isDate
 * @category Common Helpers
 * @summary Is the given value a date?
 *
 * @description
 * Returns true if the given value is an instance of Date. The function works for dates transferred across iframes.
 *
 * ### v2.0.0 breaking changes:
 *
 * - [Changes that are common for the whole library](https://github.com/date-fns/date-fns/blob/master/docs/upgradeGuide.md#Common-Changes).
 *
 * @param {*} value - the value to check
 * @returns {boolean} true if the given value is a date
 * @throws {TypeError} 1 arguments required
 *
 * @example
 * // For a valid date:
 * var result = isDate(new Date())
 * //=> true
 *
 * @example
 * // For an invalid date:
 * var result = isDate(new Date(NaN))
 * //=> true
 *
 * @example
 * // For some value:
 * var result = isDate('2014-02-31')
 * //=> false
 *
 * @example
 * // For an object:
 * var result = isDate({})
 * //=> false
 */
export default function isDate(value) {
  requiredArgs(1, arguments)

  return (
    value instanceof Date ||
    (typeof value === 'object' &&
      Object.prototype.toString.call(value) === '[object Date]')
  )
}