Decorators with class properties cause Babel's classCallCheck to fail

[damonmaria]

I have the following code:

import React, from 'react'
import { observer } from 'mobx-react'

@observer
class OrgsPage extends React.Component {
  render = () =>
    <div>Hello</div>
}
export default OrgsPage

When I try and use this as a component in React I get:

babel-runtime.js?hash=71fe7d0…:108 Uncaught TypeError: Cannot call a class as a function
    at classCallCheck (http://localhost:4000/packages/babel-runtime.js?hash=71fe7d0d01dc808e2a80cb0a7958fb31e46323d5:108:13)
    at Constructor.OrgsPage (http://localhost:4000/app/app.js?hash=7ba134c41c0997baa4644e0e7b2750d3c4341f2f:1794:37)
    at Constructor.render (http://localhost:4000/packages/modules.js?hash=58c8b0b77d6bd50615c786bc9f20afd954ec52db:129542:32)
    at Object.allowStateChanges (http://localhost:4000/packages/modules.js?hash=58c8b0b77d6bd50615c786bc9f20afd954ec52db:116825:15)
    at Reaction.<anonymous> (http://localhost:4000/packages/modules.js?hash=58c8b0b77d6bd50615c786bc9f20afd954ec52db:129440:44)
...

This does not happen if I do any of the following:

• Remove @observer
• Change the render method to be a normal method (not a class property)
• Have render as a normal method and add in another class property under a different name

My .babelrc:

{
  "presets": [
    "react",
    "es2015",
    "stage-3"
  ],
  "plugins": [
    "transform-decorators-legacy",
    "transform-class-properties"
  ]
}

And (what I think is) relevant package.json:

    "babel-plugin-transform-decorators-legacy": "^1.3.4",
    "babel-preset-es2015": "^6.18.0",
    "babel-preset-react": "^6.16.0",
    "babel-preset-stage-0": "^6.16.0",

This was working for me, and then updated some of my npm packages (like babel-preset-es2015) and then it stopped working. But npm being npm I can't see to get my node_modules back into that state again to prove it's a change between 6.16.0 and 6.18.0 of babel-preset-es2015.

[zoecarver]

This seems to be working. I have a working repo here.