core-js/modules/es.array.push.js

'use strict';
var $ = require('../internals/export');
var toObject = require('../internals/to-object');
var lengthOfArrayLike = require('../internals/length-of-array-like');
var setArrayLength = require('../internals/array-set-length');
var doesNotExceedSafeInteger = require('../internals/does-not-exceed-safe-integer');
var fails = require('../internals/fails');

var INCORRECT_TO_LENGTH = fails(function () {
  return [].push.call({ length: 0x100000000 }, 1) !== 4294967297;
});

// V8 <= 121 and Safari <= 15.4; FF < 23 throws InternalError
// https://bugs.chromium.org/p/v8/issues/detail?id=12681
var properErrorOnNonWritableLength = function () {
  try {
    // eslint-disable-next-line es/no-object-defineproperty -- safe
    Object.defineProperty([], 'length', { writable: false }).push();
  } catch (error) {
    return error instanceof TypeError;
  }
};

var FORCED = INCORRECT_TO_LENGTH || !properErrorOnNonWritableLength();

// `Array.prototype.push` method
// https://tc39.es/ecma262/#sec-array.prototype.push
$({ target: 'Array', proto: true, arity: 1, forced: FORCED }, {
  // eslint-disable-next-line no-unused-vars -- required for `.length`
  push: function push(item) {
    var O = toObject(this);
    var len = lengthOfArrayLike(O);
    var argCount = arguments.length;
    doesNotExceedSafeInteger(len + argCount);
    for (var i = 0; i < argCount; i++) {
      O[len] = arguments[i];
      len++;
    }
    setArrayLength(O, len);
    return len;
  }
});