array.prototype.findlastindex/shim.js

An ESnext spec-compliant `Array.prototype.findLastIndex` shim/polyfill/replacement that works as far down as ES3.

'use strict';

var define = require('define-properties');
var getPolyfill = require('./polyfill');
var shimUnscopables = require('es-shim-unscopables');

module.exports = function shimFindLastIndex() {
	var polyfill = getPolyfill();
	define(
		Array.prototype,
		{ findLastIndex: polyfill },
		{ findLastIndex: function () { return Array.prototype.findLastIndex !== polyfill; } }
	);

	shimUnscopables('findLastIndex');

	return polyfill;
};