babel: Cannot read property 'helpers' of undefined

Hi. I got a following error: ‘Cannot read property ‘helpers’ of undefined.’ Hope anyone can help with that.

Also I got a https://github.com/babel/babel/issues/7110 without “plugins” in my .babelrc.

.babelrc, package.json

{
  "presets": [
    [
      "@babel/preset-env",
      {
        "targets": {
          "browsers": [
            "last 2 versions"
          ]
        }
      }
    ]
  ],
  "plugins": [
    "@babel/plugin-transform-runtime"
  ]
}

{
  "devDependencies": {
    "@babel/cli": "^7.0.0-beta.36",
    "@babel/core": "^7.0.0-beta.36",
    "@babel/plugin-transform-runtime": "^7.0.0-beta.36",
    "@babel/preset-env": "^7.0.0-beta.36"
  },
  "dependencies": {
    "@babel/runtime": "^7.0.0-beta.36"
  }
}

Error

Cannot read property 'helpers' of undefined at _default node_modules\@babel\plugin-transform-runtime\lib\index.js:17:25)

About this issue

Original URL
State: closed
Created 7 years ago
Comments: 18 (9 by maintainers)

Most upvoted comments

@nicolo-ribaudo I also had tryed to reinstal all my dependencies and after that all is worked fine. Perhaps it’s because I was trying to many solution to solve my issue from the begining and I just had polluted node_modules with different versions of different packages. And parcel just don’t know what to choose or something like that.

@nicolo-ribaudo @xtuc Thanks for you support. Very appreciate.

swymmwys on Jan 2, 2018

If you’re using babel-loader@7, which is what is automatically installed, along with @babel/core beta, try use babel-loader@^8.0.0-beta.0.

yarn add --dev babel-loader@^8.0.0-beta.0

Cannot read property ‘helpers’ of undefined with babel and webapck

fengyun2 on Mar 6, 2018

FYI @swymmwys https://github.com/parcel-bundler/parcel/pull/475

xtuc on Jan 2, 2018

@swymmwys I tested your code with Babel 6 (without using parcel) and it works

Output

"use strict";

Object.defineProperty(exports, "__esModule", {
    value: true
});

var _regenerator = require("babel-runtime/regenerator");

var _regenerator2 = _interopRequireDefault(_regenerator);

var _asyncToGenerator2 = require("babel-runtime/helpers/asyncToGenerator");

var _asyncToGenerator3 = _interopRequireDefault(_asyncToGenerator2);

var _classCallCheck2 = require("babel-runtime/helpers/classCallCheck");

var _classCallCheck3 = _interopRequireDefault(_classCallCheck2);

var _createClass2 = require("babel-runtime/helpers/createClass");

var _createClass3 = _interopRequireDefault(_createClass2);

function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }

var Page = function () {
    function Page(url) {
        (0, _classCallCheck3.default)(this, Page);

        this._url = "src/app/pages/" + url;
        this.html = "";
    }

    (0, _createClass3.default)(Page, [{
        key: "load",
        value: function () {
            var _ref = (0, _asyncToGenerator3.default)( /*#__PURE__*/_regenerator2.default.mark(function _callee() {
                var _this = this;

                return _regenerator2.default.wrap(function _callee$(_context) {
                    while (1) {
                        switch (_context.prev = _context.next) {
                            case 0:
                                if (!this.html) {
                                    _context.next = 2;
                                    break;
                                }

                                return _context.abrupt("return", this.html);

                            case 2:
                                return _context.abrupt("return", fetch(this._url).then(function (html) {
                                    return _this.html = html;
                                }));

                            case 3:
                            case "end":
                                return _context.stop();
                        }
                    }
                }, _callee, this);
            }));

            function load() {
                return _ref.apply(this, arguments);
            }

            return load;
        }()
    }]);
    return Page;
}();

exports.default = Page;

I don’t know Parcel so I don’t know what the issue could help. As a workaround, you can include regenerator-runtime/runtime in your entry point.

nicolo-ribaudo on Jan 2, 2018