es.number.to-precision.js

'use strict';
var $ = require('../internals/export');
var fails = require('../internals/fails');
var thisNumberValue = require('../internals/this-number-value');

var nativeToPrecision = 1.0.toPrecision;

var FORCED = fails(function () {
  // IE7-
  return nativeToPrecision.call(1, undefined) !== '1';
}) || !fails(function () {
  // V8 ~ Android 4.3-
  nativeToPrecision.call({});
});

// `Number.prototype.toPrecision` method
// https://tc39.github.io/ecma262/#sec-number.prototype.toprecision
$({ target: 'Number', proto: true, forced: FORCED }, {
  toPrecision: function toPrecision(precision) {
    return precision === undefined
      ? nativeToPrecision.call(thisNumberValue(this))
      : nativeToPrecision.call(thisNumberValue(this), precision);
  }
});