core-js/internals/iterator-helper-without-closing-on-early-error.js

Standard library

'use strict';
var globalThis = require('../internals/global-this');

// https://github.com/tc39/ecma262/pull/3467
module.exports = function (METHOD_NAME, ExpectedError) {
  var Iterator = globalThis.Iterator;
  var IteratorPrototype = Iterator && Iterator.prototype;
  var method = IteratorPrototype && IteratorPrototype[METHOD_NAME];

  var CLOSED = false;

  if (method) try {
    method.call({
      next: function () { return { done: true }; },
      'return': function () { CLOSED = true; }
    }, -1);
  } catch (error) {
    // https://bugs.webkit.org/show_bug.cgi?id=291195
    if (!(error instanceof ExpectedError)) CLOSED = false;
  }

  if (!CLOSED) return method;
};