es.number.constructor.js

'use strict';
var $ = require('../internals/export');
var IS_PURE = require('../internals/is-pure');
var DESCRIPTORS = require('../internals/descriptors');
var global = require('../internals/global');
var path = require('../internals/path');
var uncurryThis = require('../internals/function-uncurry-this');
var isForced = require('../internals/is-forced');
var hasOwn = require('../internals/has-own-property');
var inheritIfRequired = require('../internals/inherit-if-required');
var isPrototypeOf = require('../internals/object-is-prototype-of');
var isSymbol = require('../internals/is-symbol');
var toPrimitive = require('../internals/to-primitive');
var fails = require('../internals/fails');
var getOwnPropertyNames = require('../internals/object-get-own-property-names').f;
var getOwnPropertyDescriptor = require('../internals/object-get-own-property-descriptor').f;
var defineProperty = require('../internals/object-define-property').f;
var thisNumberValue = require('../internals/this-number-value');
var trim = require('../internals/string-trim').trim;

var NUMBER = 'Number';
var NativeNumber = global[NUMBER];
var PureNumberNamespace = path[NUMBER];
var NumberPrototype = NativeNumber.prototype;
var TypeError = global.TypeError;
var arraySlice = uncurryThis(''.slice);
var charCodeAt = uncurryThis(''.charCodeAt);

// `ToNumeric` abstract operation
// https://tc39.es/ecma262/#sec-tonumeric
var toNumeric = function (value) {
  var primValue = toPrimitive(value, 'number');
  return typeof primValue == 'bigint' ? primValue : toNumber(primValue);
};

// `ToNumber` abstract operation
// https://tc39.es/ecma262/#sec-tonumber
var toNumber = function (argument) {
  var it = toPrimitive(argument, 'number');
  var first, third, radix, maxCode, digits, length, index, code;
  if (isSymbol(it)) throw TypeError('Cannot convert a Symbol value to a number');
  if (typeof it == 'string' && it.length > 2) {
    it = trim(it);
    first = charCodeAt(it, 0);
    if (first === 43 || first === 45) {
      third = charCodeAt(it, 2);
      if (third === 88 || third === 120) return NaN; // Number('+0x1') should be NaN, old V8 fix
    } else if (first === 48) {
      switch (charCodeAt(it, 1)) {
        case 66: case 98: radix = 2; maxCode = 49; break; // fast equal of /^0b[01]+$/i
        case 79: case 111: radix = 8; maxCode = 55; break; // fast equal of /^0o[0-7]+$/i
        default: return +it;
      }
      digits = arraySlice(it, 2);
      length = digits.length;
      for (index = 0; index < length; index++) {
        code = charCodeAt(digits, index);
        // parseInt parses a string to a first unavailable symbol
        // but ToNumber should return NaN if a string contains unavailable symbols
        if (code < 48 || code > maxCode) return NaN;
      } return parseInt(digits, radix);
    }
  } return +it;
};

var FORCED = isForced(NUMBER, !NativeNumber(' 0o1') || !NativeNumber('0b1') || NativeNumber('+0x1'));

// `Number` constructor
// https://tc39.es/ecma262/#sec-number-constructor
var NumberWrapper = function Number(value) {
  var n = arguments.length < 1 ? 0 : NativeNumber(toNumeric(value));
  var dummy = this;
  // check on 1..constructor(foo) case
  return isPrototypeOf(NumberPrototype, dummy) && fails(function () { thisNumberValue(dummy); })
    ? inheritIfRequired(Object(n), dummy, NumberWrapper) : n;
};
NumberWrapper.prototype = NumberPrototype;
if (FORCED && !IS_PURE) NumberPrototype.constructor = NumberWrapper;

$({ global: true, constructor: true, wrap: true, forced: FORCED }, {
  Number: NumberWrapper
});

var copyStaticProperties = function (target, source) {
  for (var keys = DESCRIPTORS ? getOwnPropertyNames(source) : (
    // ES3:
    'MAX_VALUE,MIN_VALUE,NaN,NEGATIVE_INFINITY,POSITIVE_INFINITY,' +
    // ES2015 (in case, if modules with ES2015 Number statics required before):
    'EPSILON,MAX_SAFE_INTEGER,MIN_SAFE_INTEGER,isFinite,isInteger,isNaN,isSafeInteger,parseFloat,parseInt,' +
    // ESNext
    'fromString,range'
  ).split(','), j = 0, key; keys.length > j; j++) {
    if (hasOwn(source, key = keys[j]) && !hasOwn(target, key)) {
      defineProperty(target, key, getOwnPropertyDescriptor(source, key));
    }
  }
};

if (IS_PURE && PureNumberNamespace) copyStaticProperties(path[NUMBER], PureNumberNamespace);
if (FORCED || IS_PURE) copyStaticProperties(path[NUMBER], NativeNumber);