TypeError: undefined is not a function this._children[typeof Symbol === 'function'? Symbol.iterator: '@@iterator']()')

[CarbonC]

Version

Tell us which versions you are using:

• react-native-router-flux v4.0.0-beta.22 (v3 is not supported)
• react-native v0.49.3

Expected behaviour

Router don't crash

Actual behaviour

Router crash on android when navigating between screens, with error:

TypeError: undefined is not a function this._children[typeof Symbol === 'function'? Symbol.iterator: '@@iterator']()')

It is maybe linked to this:
react-navigation/react-navigation#1777

Steps to reproduce

For non-obvious bugs, please fork this component, modify Example project to reproduce your issue and include link here.

1. Just run any app with StackNavigator and babelrc es2015 and stage-0 presets

[CarbonC]

Tested a little bit more options, it really seems to be a bug inherent to the stack navigator. The tab navigator is working well...

[cmeiller]

Same here

[cmeiller]

@CarbonC I solved my problem by importing babel-polyfill, can you try this?

[CarbonC]

Yeah, i just updated the babel-react-native-preset version right now and it fixed it. Thanks!

[sfreeman28]

@CarbonC Hi, I just started trying out React and having trouble with Navigation.

I got TabNavigator working, but not StackNavigator.

Can you please state which version of babel-react-native-preset you updated to fix the issue?

For reference these are my versions:

  "name": "SimpleApp",
  "version": "0.0.1",
  "private": true,
  "scripts": {
    "start": "node node_modules/react-native/local-cli/cli.js start",
    "test": "jest"
  },
  "dependencies": {
    "react": "16.0.0-beta.5",
    "react-native": "0.49.5",
    "react-navigation": "^1.0.0-beta.16"
  },
  "devDependencies": {
    "babel-jest": "21.2.0",
    "babel-preset-react-native": "4.0.0",
    "jest": "21.2.1",
    "react-test-renderer": "16.0.0-beta.5"
  },
  "jest": {
    "preset": "react-native"
  }
}

Thanks

[skicson]

@sfreeman28 - your error is probably related to this issue.

[sfreeman28]

@skicson Yea thanks I just saw that Issue report and looks like what I am getting. Thanks for the help

[erichua23]

npm install --save babel-polyfill

and add

import "babel-polyfill"

to your entry file.

This work for me on Android.