var $export = require('./_export');
var toAbsoluteIndex = require('./_to-absolute-index');
var fromCharCode = String.fromCharCode;
var $fromCodePoint = String.fromCodePoint;

// length should be 1, old FF problem
$export($export.S + $export.F * (!!$fromCodePoint && $fromCodePoint.length != 1), 'String', {
  // 21.1.2.2 String.fromCodePoint(...codePoints)
  fromCodePoint: function fromCodePoint(x) { // eslint-disable-line no-unused-vars
    var res = [];
    var aLen = arguments.length;
    var i = 0;
    var code;
    while (aLen > i) {
      code = +arguments[i++];
      if (toAbsoluteIndex(code, 0x10ffff) !== code) throw RangeError(code + ' is not a valid code point');
      res.push(code < 0x10000
        ? fromCharCode(code)
        : fromCharCode(((code -= 0x10000) >> 10) + 0xd800, code % 0x400 + 0xdc00)
      );
    } return res.join('');
  }
});