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

[NathHorrigan]

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 ?

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Maybe the issue has been fixed in a recent release, or perhaps it is not affecting a lot of people. If you think this issue should definitely remain open, please let us know why. Thank you for your contributions.

[joeyfigaro]

Also having issues with this. Using babel-preset-react-native makes no difference, unfortunately.

[joeyfigaro]

.babelrc

{
	"presets": [
		"expo",
		"react-native"
	],
	"plugins": [
		"transform-react-jsx-source",
		"transform-function-bind",
		["module-resolver", {
			"root": ["./"],
			"alias": {
				"root": ".",
				"src": "./src",
				"components": "./src/components",
				"modals": "./src/modals",
				"screens": "./src/screens",
				"api": "./src/api",
				"redux": "./node_modules/redux",
				"@redux": "./src/_redux",
				"utils": "./src/utils",
				"assets": "./src/assets",
				"tests": "./src/__tests__",
				"tests/components": "./src/components/__tests__",
				"tests/redux": "./src/_redux/__tests__"
			},
			"extensions": [".js", ".ios.js", ".android.js"]
		}]
	],
	"env": {
		"test": {
			"presets": [
				"react-native"
			]
		}
	}
}

package.json

{
        ...
	"dependencies": {
		"color": "^2.0.1",
		"expo": "^25.0.0",
		"moment": "^2.20.1",
		"prop-types": "^15.6.0",
		"ramda": "^0.25.0",
		"ramda-extension": "^0.2.1",
		"react": "^16.2.0",
		"react-native": "https://github.com/expo/react-native/archive/sdk-25.0.0.tar.gz",
		"react-native-actionsheet": "^2.3.0",
		"react-native-communications": "^2.2.1",
		"react-native-datepicker": "^1.6.0",
		"react-native-elements": "^0.18.5",
		"react-native-iphone-x-helper": "^1.0.1",
		"react-native-pathjs-charts": "0.0.33",
		"react-native-swipeable": "^0.6.0",
		"react-native-swiper": "^1.5.13",
		"react-navigation": "^1.0.0-beta.27",
		"react-redux": "^5.0.6",
		"react-search-input": "^0.11.3",
		"redux": "^3.7.2",
		"redux-api-middleware": "^2.2.0",
		"redux-logger": "^3.0.6",
		"redux-persist": "^5.4.0",
		"redux-thunk": "^2.2.0",
		"reselect": "^3.0.1"
	},
	"devDependencies": {
		"babel-eslint": "^8.2.1",
		"babel-plugin-module-alias": "^1.6.0",
		"babel-plugin-transform-react-jsx-source": "^6.22.0",
		"babel-plugin-module-resolver": "^3.0.0",
		"babel-plugin-transform-function-bind": "^6.22.0",
		"babel-preset-env": "^1.6.1",
		"babel-preset-react-native": "^4.0.0",
		"eslint": "^4.15.0",
		"eslint-config-airbnb": "^16.1.0",
		"eslint-import-resolver-babel-module": "^4.0.0",
		"eslint-loader": "^1.9.0",
		"eslint-plugin-import": "^2.8.0",
		"eslint-plugin-jsx-a11y": "^6.0.3",
		"eslint-plugin-react": "^7.5.1",
		"eslint-plugin-react-native": "^3.2.0",
		"jest-expo": "^25.0.0",
		"quokka-signet-explorer": "^1.3.0",
		"remote-redux-devtools": "^0.5.12"
	}
}

[joeyfigaro]

After doing the dependency + cache nuking a handful of times it started to work again.

- removed node_modules
- cleared $TMPDIR files/directories
- cleared yarn cache
- reinstall dependencies
- opened XDE
- turned on development mode and restarted project
- turned off development mode and restarted project

update: we're back to having issues again. Looks like the only thing that currently works is to update the polyfill in Libraries, as suggested by @Leko

[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.

_{How to Contribute • What to Expect from Maintainers}