[0.56.0-rc-2] Decorator support broken

[alexwasner]

Environment

Run react-native info in your terminal and paste its contents here.

React Native Environment Info:
    System:
      OS: macOS High Sierra 10.13.4
      CPU: x64 Intel(R) Core(TM) i7-7820HQ CPU @ 2.90GHz
      Memory: 148.02 MB / 16.00 GB
      Shell: 5.3 - /bin/zsh
    Binaries:
      Node: 8.11.2 - /usr/local/bin/node
      Yarn: 1.6.0 - /usr/local/bin/yarn
      npm: 6.1.0 - /usr/local/bin/npm
      Watchman: 4.9.0 - /usr/local/bin/watchman
    SDKs:
      iOS SDK:
        Platforms: iOS 11.3, macOS 10.13, tvOS 11.3, watchOS 4.3
    IDEs:
      Android Studio: 3.0 AI-171.4443003
      Xcode: 9.3.1/9E501 - /usr/bin/xcodebuild
    npmPackages:
      react: ^16.3.2 => 16.4.1
      react-native: ^0.56.0-rc.2 => 0.56.0-rc.2
    npmGlobalPackages:
      eslint-plugin-react-native: 3.2.1
      react-native-cli: 2.0.1
      react-native-git-upgrade: 0.2.7

Description

After upgrading to RN56, I am receiving a red screen for error:(...node-modules/react-native-Libraries/react-native/react-native-implementation.js: Cannot find module 'react-native-stage-0/decorator-support'....
My .babelrc file is as follows and worked on previous versions:

{
  "presets": [
  	"react-native",
  	"react-native-stage-0/decorator-support"
  ],
  "plugins": [
    "transform-decorators-legacy"
  ],
  "sourceMaps": true
}

Dev deps in package.json

  "devDependencies": {
    "babel-eslint": "^8.2.3",
    "babel-jest": "21.2.0",
    "babel-preset-react-native": "5.0.2",
    "babel-preset-react-native-stage-0": "^1.0.1",
    "eslint": "^4.19.1",
    "eslint-plugin-eslint-comments": "^2.0.2",
    "eslint-plugin-flowtype": "^2.49.3",
    "eslint-plugin-jest": "^21.17.0",
    "eslint-plugin-prettier": "^2.6.0",
    "eslint-plugin-react-native": "^3.2.1",
    "jest": "21.2.1",
    "react-test-renderer": "^16.4.1"
  },

Reproducible Demo

Use provided .babelrc on a 0.56.0-rc2 project

react-native init example --version="0.56.0-rc.2"
cd ./example
yarn add --dev babel-preset-react-native-stage-0

[vovkasm]

RN 0.56 uses babel 7, but babel-preset-react-native-stage-0 clearly depends on babel 6, see: https://github.com/skevy/babel-preset-react-native-stage-0/blob/master/package.json#L10-L18

It will not work )

[jshearer]

I solved this by using

"babel-plugin-transform-decorators-legacy": "^1.3.5",

and

"plugins": [
    "transform-decorators-legacy",
]

In my .babelrc file.

[hramos]

@alexwasner OK to close this issue?

[fwh1990]

@jshearer

No, you should install @babel/plugin-proposal-decorators for babel 7. The plugin you use was for babel 6

And babel had change it's package prefix to @babel since babel-7-beta.4. You can see babel github here

[kelset]

This is not a bug caused by the changes in the default config.

It’ll be impossible to account for custom configs since it’s certain that some third party plugins will break in babel 7, and it’s up to the plugin authors to fix them/users to change their config.

And thanks to suggestions from @jshearer and @fwh1990 I think we can close this but not lock for a bit, so that the conv about how to properly tackle can move forward.