'babelHelpers.asyncToGenerator is not a function' error only on iOS

Is this a bug report?

Yes

Have you read the Contributing Guidelines?

No

Environment

Environment: OS: macOS Sierra 10.12.1 Node: 7.9.0 Yarn: 0.20.3 npm: 4.2.0 Watchman: 4.9.0 Xcode: Xcode 8.3.3 Build version 8E3004b Android Studio: 2.3 AI-162.4069837

Packages: (wanted => installed) react: 16.0.0-alpha.12 => 16.0.0-alpha.12 react-native: 0.48.3 => 0.48.3

Target Platform: iOS (10.3) Android

Expected Behavior

App to load as it does on android .

Actual Behavior

Error: babelHelpers.asyncToGenerator is not a function

[Leko]

I got same error in react-native 0.50.4. I think that babelHelpers.asyncToGenerator is missing in Libraries/polyfills/babelHelpers.js, right ?

It works fine after add babelHelpers.asyncToGenerator to Libraries/polyfills/babelHelpers.js. (It is partial of require('babel-core').buildExternalHelpers('asyncToGenerator'.split(' ')).)

babelHelpers.asyncToGenerator = function (fn) {
  return function () {
    var gen = fn.apply(this, arguments);
    return new Promise(function (resolve, reject) {
      function step(key, arg) {
        try {
          var info = gen[key](arg);
          var value = info.value;
        } catch (error) {
          reject(error);
          return;
        }

        if (info.done) {
          resolve(value);
        } else {
          return Promise.resolve(value).then(function (value) {
            step("next", value);
          }, function (err) {
            step("throw", err);
          });
        }
      }

      return step("next");
    });
  };
};

It is bug ? I made a mistake ?

[react-native-bot]

Thanks for posting this! It looks like you may not be using the latest version of React Native, v0.53.0, released on January 2018. Can you make sure this issue can still be reproduced in the latest version?

I am going to close this, but please feel free to open a new issue if you are able to confirm that this is still a problem in v0.53.0 or newer.

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