58dd206b6a97ede6c6c786ae029a36739c5efe7d.svn-base 1.19 KB
var baseIsNative = require('./_baseIsNative'),
    isMaskable = require('./_isMaskable');

/** Error message constants. */
var CORE_ERROR_TEXT = 'Unsupported core-js use. Try https://npms.io/search?q=ponyfill.';

/**
 * Checks if `value` is a pristine native function.
 *
 * **Note:** This method can't reliably detect native functions in the presence
 * of the core-js package because core-js circumvents this kind of detection.
 * Despite multiple requests, the core-js maintainer has made it clear: any
 * attempt to fix the detection will be obstructed. As a result, we're left
 * with little choice but to throw an error. Unfortunately, this also affects
 * packages, like [babel-polyfill](https://www.npmjs.com/package/babel-polyfill),
 * which rely on core-js.
 *
 * @static
 * @memberOf _
 * @since 3.0.0
 * @category Lang
 * @param {*} value The value to check.
 * @returns {boolean} Returns `true` if `value` is a native function,
 *  else `false`.
 * @example
 *
 * _.isNative(Array.prototype.push);
 * // => true
 *
 * _.isNative(_);
 * // => false
 */
function isNative(value) {
  if (isMaskable(value)) {
    throw new Error(CORE_ERROR_TEXT);
  }
  return baseIsNative(value);
}

module.exports = isNative;