[0.56][RELEASE] Bundler cuts off some used babel helpers in release build (decorators issue)

[farwayer]

• Review the documentation: https://facebook.github.io/react-native
• Search for existing issues: https://github.com/facebook/react-native/issues
• Use the latest React Native release: https://github.com/facebook/react-native/releases

Environment

  React Native Environment Info:
    System:
      OS: Linux 4.17 Arch Linux rolling
      CPU: x64 Intel(R) Core(TM) i7-3770K CPU @ 3.50GHz
      Memory: 1.06 GB / 7.47 GB
      Shell: 5.5.1 - /bin/zsh
    Binaries:
      Node: 10.6.0 - /usr/bin/node
      Yarn: 1.7.0 - /usr/bin/yarn
      npm: 6.1.0 - /usr/bin/npm
      Watchman: 4.9.0 - /usr/bin/watchman
    SDKs:
      Android SDK:
        Build Tools: 23.0.1, 23.0.3, 25.0.2, 26.0.1, 26.0.2, 27.0.0, 27.0.3
        API Levels: 22, 23, 24, 25, 26, 27
    npmPackages:
      react: ^16.4.1 => 16.4.1 
      react-native: ^0.56.0 => 0.56.0 
    npmGlobalPackages:
      react-native-cli: 2.0.1
      react-native-git-upgrade: 0.2.7

Description

Bundler cuts off some used babel helpers in release build. Look like by mistake while optimization.
For example initializerDefineProperty and applyDecoratedDescriptor needed by @babel/proposal-decorators.

Reproducible Demo

{
  "presets": ["react-native"],
  "plugins": [
    ["@babel/proposal-decorators", {"legacy": true}]
  ]
}

"devDependencies": {
  "@babel/plugin-proposal-decorators": "7.0.0-beta.47"
}

function test() {}

class Test {
  @test val;
}

undefined is not a function (evaluating 'babelHelpers.applyDecoratedDescriptor(_class.prototype, "val", [test], {
    enumerable: true,
    initializer: null
  })')

Workaround 1 (can have side effects)

Be care because this workaround can bring some errors with external libs.

For RN 0.56:

yarn add --dev @babel/plugin-transform-runtime@7.0.0-beta.47

.babelrc

{
  "presets": ["react-native"],
  "plugins": [
    ["@babel/plugin-proposal-decorators", {"legacy": true}],
    ["@babel/plugin-transform-runtime", {
      "polyfill": false,
      "regenerator": false
    }]
  ]
}

For RN 0.57:

yarn add --dev @babel/plugin-transform-runtime@7.0.0

.babelrc

{
  "presets": ["module:metro-react-native-babel-preset"],
  "plugins": [
    ["@babel/plugin-proposal-decorators", {"legacy": true}],
    ["@babel/plugin-transform-runtime", {
      "polyfill": false,
      "regenerator": false
    }]
  ]
}

Workaround 2

Move app initialization to some other file (I'm using src/ dir for source) and update root index.js file.
N.B. require main app code instead of import because require executed after.

For RN 0.56:

yarn add @babel/runtime@7.0.0-beta.47

Root index.js

import applyDecoratedDescriptor from '@babel/runtime/helpers/es6/applyDecoratedDescriptor'
import initializerDefineProperty from '@babel/runtime/helpers/es6/initializerDefineProperty'

Object.assign(babelHelpers, {
  applyDecoratedDescriptor,
  initializerDefineProperty,
});

require('./src');

For RN 0.57:

yarn add @babel/runtime@7.0.0

Root index.js

import applyDecoratedDescriptor from '@babel/runtime/helpers/esm/applyDecoratedDescriptor'
import initializerDefineProperty from '@babel/runtime/helpers/esm/initializerDefineProperty'

Object.assign(babelHelpers, {
  applyDecoratedDescriptor,
  initializerDefineProperty,
});

require('./src');

[thientnc-ibl]

@farwayer
Where can this code be placed?

import initializerDefineProperty from '@babel/runtime/helpers/es6/initializerDefineProperty'
Object.assign(babelHelpers, {applyDecoratedDescriptor, initializerDefineProperty});
require('./src');```

[farwayer]

@thientnc-ibl This is root index.js file. Put your app code in some other file and require() it at the end of root index.

[thientnc-ibl]

The RELEASE build is OK now, bravo... We should write this work around to React native 0.56 doc

[janicduplessis]

RN includes its own version of babel-helpers but it does not include the applyDecoratedDescriptor. Facebook probably doesn't use decorators so this went unnoticed. I'll see if we can include it to get this fixed, in the meantime the workaround is valid.

[folofse]

I was stuck with this problem in my release build until I manually recreated the android bundle. I thought the bundle was recreated automaticly on release. But I had to run the terminal code after each change: 'react-native bundle --platform android --dev false --entry-file index.android.js --bundle-output android/app/src/main/assets/index.android.bundle --assets-dest android/app/src/main/res/'

[hvaoc]

Faced the same error with React Native 0.56, used combination of resolutions proposed including the Workaround 2 by @farwayer above.

Steps that I followed:

1. Clean up dependencies

rm -rf node_modules
yarn
yarn upgrade react-native@0.56.0

2. @farwayer suggested workaround 2

Check the version of babel components used with React Native by checking the yarn.lock or package-lock.json and match @babel/runtime with the same version. React native 0.56 is using babel 7.0.0-beta.47.

yarn add @babel/runtime@7.0.0-beta.47

index.js

import {AppRegistry} from 'react-native'


// RN 0.56 Release version crashes
// import App from './src/App'
// AppRegistry.registerComponent('MyApp', () => App)

// Workaround: RN 0.56 Release version crashes
// Sources:
//      https://github.com/facebook/react-native/issues/19827
//      https://github.com/facebook/react-native/issues/20150

import applyDecoratedDescriptor from '@babel/runtime/helpers/es6/applyDecoratedDescriptor'
import initializerDefineProperty from '@babel/runtime/helpers/es6/initializerDefineProperty'

Object.assign(babelHelpers, {applyDecoratedDescriptor, initializerDefineProperty})

// Your main app code is in /src/index.js
AppRegistry.registerComponent('MyApp', () => require('./src').default)

Tested iOS / Android - Debug and Release version on Simulators and Devices. - All of them are working fine.

Note: I am also using decorators for MobX and custom .babelrc

package.json

{
  "name": "MyApp",
  "version": "0.0.1",
  "dependencies": {
    "@babel/plugin-proposal-decorators": "7.0.0-beta.47",
    "@babel/runtime": "7.0.0-beta.47",
    "mobx": "^5.0.3",
    "mobx-react": "^5.2.3",
    "react": "16.4.1",
    "react-native": "0.56.0"
  },
  "devDependencies": {
    "babel-jest": "23.4.0",
    "babel-preset-react-native": "^5",
    "flow-bin": "^0.76.0",
    "jest": "^23.4.1",
    "jsc-android": "^224109.0.0",
    "react-native-cli": "^2.0.1",
    "react-test-renderer": "16.4.1"
  },
  "jest": {
    "preset": "react-native"
  }
}

.babelrc

{
  "presets": [
    "react-native"
  ],
  "plugins": [
    [
      "@babel/plugin-proposal-decorators",
      {
        "legacy": true
      }
    ]
  ]
}

[scriptum]

With decorators plugin jest is broken too:

  ● Test suite failed to run

    TypeError: babelHelpers.applyDecoratedDescriptor is not a function

[mehulmpt]

Your solution works flawlessly @farwayer. My react-native-vector-icons package was broken with the approach I was trying earlier and this one works fine with it too! +1

[csotiriou]

This error also exists in React Native 0.57 rc3.

[164738777]

This error also exists in React Native 0.57 rc3.
+1

[lxcid]

In metro-react-native-babel-preset, it is stated that @babel/plugin-transform-flow-strip-types need to be before @babel/plugin-proposal-class-properties.

the flow strip types plugin must go BEFORE class properties! there'll be a test case that fails if you don't.

https://github.com/facebook/metro/blob/579b12974d13c7f02b2c58540ce8fddcb6a3e423/packages/metro-react-native-babel-preset/src/configs/main.js#L19-L21

This kinda explain why flow is affecting the babel output as describe around the issue…

If you provide your own plugins, it get applied first before presets, as described in Plugin Ordering section at https://babeljs.io/docs/en/plugins/#plugin-ordering

So, if you need decorators, you will have to place @babel/plugin-proposal-decorators above @babel/plugin-proposal-class-properties in plugins, which get executed first, thus not applying the @babel/plugin-transform-flow-strip-types, See https://babeljs.io/docs/en/next/babel-plugin-proposal-decorators.html

The fix for me is to add @babel/plugin-transform-flow-strip-types before the 2 other plugins…

{
  "plugins": [
    [
      "@babel/plugin-transform-flow-strip-types"
    ],
    [
      "@babel/plugin-proposal-decorators",
      {
        "legacy": true
      }
    ],
    [
      "@babel/plugin-proposal-class-properties",
      {
        "loose": true
      }
    ]
  ],
}

[rborn]

For me none of the above solutions/workarounds work.
I also tried to upgrade to 0.57 but no luck.

[rborn]

SOLVED 🎉, thanks to @Amnesthesia @jrnk ❤️ oblador/react-native-vector-icons#801 (comment)

Tested both ios/android debug/release (didn't upload to stores though but delivered with TestFairy so it should be just fine)

[chussum]

Thank you guys!! You guys were save me! :) 👍
Thanks!! (__)

[janicduplessis]

@rknell Sorry you are feeling this way. This took a long time to fix since it isn't a hacky patch and required major changes in the way RN handles babel helpers so we don't rely on manually adding them anymore.

A patch to move from global babelHelpers to @babel/runtime landed a few days ago, with a follow up to remove the globals completely from RN that should land soon.

Thanks for you patience on this one.

[shinriyo]

Did you resolve?

2018-10-07 16:35:58.532 [error][tid:com.facebook.react.JavaScript] undefined is not a function (near '...babelHelpers.applyDecoratedDescriptor...')

[csotiriou]

To be honest, I had to hardcode versions beta.47 of the relevant babel packages in order to get it to work. Upgrading to 7.1.2 didn't help.

[pppluto]

for me I need "@babel/core": "^7.0.0" for android

[Fsarmento]

This issue seams to be solved in 0.57.4 (60b05ca).

We can go back to:

import { AppRegistry } from 'react-native';
import App from './App';

AppRegistry.registerComponent('myApp', () => App);

[Sushant-Sardeshpande]

Getting the same on updating from 0.55 to 0.58.6
Did not get this on the first package install but the next time I did it, getting it ever since

Edit: For me, just a --reset-cache for packager solved it, been working with a copy using 0.55 as well, not sure if that created an issue the second time around....

[AdamGerthel]

I've tried to understand the workarounds here and if they're still needed or not. I'm running RN using Expo v32.0, and I'm heavily invested in decorators (due to MobX), and I'm getting this error when trying to run the production version.

What do I do? I'm not using AppRegistry and I never have before either. Is that a requirement to fix this? How do I use @babel/runtime?

Update: Finally got it up and running again. Not entirely sure what fixed it in the end, but I upgraded from Babel 6 -> 7 and this is what my babel.config.js looks like:

module.exports = function(api) {
  api.cache(true)

  return {
    presets: ['babel-preset-expo'],
    plugins: [
      ['@babel/plugin-transform-react-jsx-source'],
      ['@babel/plugin-proposal-decorators', { legacy: true }]
    ]
  }
}

I also cleared Expo cache multiple times (expo r -c)