debian-mirror-gitlab/core-js/internals/array-method-has-species-support.js

var fails = require('../internals/fails');
var wellKnownSymbol = require('../internals/well-known-symbol');
var V8_VERSION = require('../internals/v8-version');

var SPECIES = wellKnownSymbol('species');

module.exports = function (METHOD_NAME) {
  // We can't use this feature detection in V8 since it causes
  // deoptimization and serious performance degradation
  // https://github.com/zloirock/core-js/issues/677
  return V8_VERSION >= 51 || !fails(function () {
    var array = [];
    var constructor = array.constructor = {};
    constructor[SPECIES] = function () {
      return { foo: 1 };
    };
    return array[METHOD_NAME](Boolean).foo !== 1;
  });
};