javascript - Error: Missing class properties transform

Question

Error: Missing class properties transform

Test.js:

export class Test extends Component {
  constructor (props) {
    super(props)
  }

  static contextTypes = {
    router: React.PropTypes.object.isRequired
  }

.babelrc:

{
  "presets": ["es2015", "react", "stage-0"],
  "plugins": ["transform-class-properties"]
}

package.json:

"babel-core": "^6.5.1",
"babel-eslint": "^4.1.8",
"babel-loader": "^6.2.2",
"babel-plugin-react-transform": "^2.0.0",
"babel-plugin-transform-class-properties": "^6.5.2",
"babel-preset-es2015": "^6.5.0",
"babel-preset-react": "^6.5.0",
"babel-preset-stage-0": "^6.5.0",
"babel-register": "^6.5.2",

I have scoured the web and all fixes revolve around: Upgrading to babel6, switching the order of "stage-0" to be after "es2015". All of which I have done.

Answer 1

You need to install babel-plugin-transform-class-properties:

npm install babel-plugin-transform-class-properties --save-dev

or

yarn add babel-plugin-transform-class-properties --dev

and add the following to your Babel configuration file - usually .babelrc or babel.config.js.

"plugins": ["@babel/plugin-proposal-class-properties"],