CODEWITHSUNDEEP
javascriptwebpackbabeljsecmascript-next
speak
speak

Reputation: 5382

Error: Missing class properties transform

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.

Upvotes: 95

Views: 128797

Answers (14)

Vinicius Andrade
Vinicius Andrade

Reputation: 1

If you're using create-react-app, you might add the babel specific configuration to your package.json:

  "babel": {
    "presets": [
      "react-app"
    ],
    "plugins": [
      [
        "@babel/plugin-proposal-class-properties",
        {
          "loose": true
        }
      ]
    ]
  }

Upvotes: -1

Jack
Jack

Reputation: 1

Complete working solution --

  1. Use "react-pdf": "^5.7.2" version

  2. import { Document, Page, pdfjs } from "react-pdf";

  3. Also add this inside your functional component

useEffect(() => { pdfjs.GlobalWorkerOptions.workerSrc =https://cdnjs.cloudflare.com/ajax/libs/pdf.js/${pdfjs.version}/pdf.worker.js;});

Upvotes: -1

neeraj-dixit27
neeraj-dixit27

Reputation: 2892

You need to install @babel/plugin-proposal-class-properties:

npm install @babel/plugin-proposal-class-properties --save-dev

or

yarn add @babel/plugin-proposal-class-properties --dev

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

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

Upvotes: 113

Juan Aguillón
Juan Aguillón

Reputation: 369

If you are using Babel 7.4 or newer, @babel/pollify is deprecated.

Install core-js, regenerator-runtime, @babel/plugin-proposal-class-properties and babel-plugin-transform-class-properties packages.

yarn add core-js regenerator-runtime @babel/plugin-proposal-class-properties babel-plugin-transform-class-properties --dev
// or
npm install core-js regenerator-runtime @babel/plugin-proposal-class-properties babel-plugin-transform-class-properties --save-dev

Then, add to .babelrc or babel.config.js

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

Finally, add this lines in your main js file:

import "core-js/stable";
import "regenerator-runtime/runtime";

Taked from: https://stackoverflow.com/a/54490329/9481448

Upvotes: 0

vancy-pants
vancy-pants

Reputation: 1348

I ran into this issue when I put some arrow functions into one of my classes without thinking. Once I changed the arrow functions to regular function/method definitions the error was resolved.

Upvotes: 4

Anatolyevich
Anatolyevich

Reputation: 701

Just in case anybody is actually still facing the same issue, The following blog post did help me: https://devblogs.microsoft.com/typescript/typescript-and-babel-7/

In my case (babel 7.9.6, typescript 3.9.2, webpack 4.43.0) I had to do the following:

  1. Run the following command: 

    npm install --save-dev @babel/preset-typescript @babel/preset-env @babel/plugin-proposal-class-properties @babel/plugin-proposal-object-rest-spread

  2. Create .babelrc file (yes, I didn't have one before and it did work just fine) with the following content:

    {
    "presets": [
        "@babel/env",
        "@babel/preset-typescript"
    ],
    "plugins": [
        "@babel/proposal-class-properties",
        "@babel/proposal-object-rest-spread"
    ]
}

Upvotes: 8

Vanessa Ejikeme
Vanessa Ejikeme

Reputation: 169

I had this same error and I ordered my plugins correctly in my .babelrc but it still persisted. Removing the preset parameters I defined in my webpack loader fixed it.

Former webpack config:

module: {
  rules: [
    {
      test: /.jsx?$/,
      loader: 'babel-loader',
      include: path.join(__dirname, 'src'),
      exclude: /node_modules/,
      query: {
        presets: ['es2015', 'react']
      }
    }
  ]
}

Working webpack config:

module: {
  rules: [
    {
      test: /.jsx?$/,
      loader: 'babel-loader',
      include: path.join(__dirname, 'src'),
      exclude: /node_modules/
    }
  ]
}

Upvotes: 3

Jamal S
Jamal S

Reputation: 1835

The fix in my case was defining 'transform-class-properties' plugin in the options attribute of my webpack.config.js, i'm using babel V6

 rules:[
    .....,
    {
       test: /\.(js|jsx)$/,
       exclude: /(node_modules|bower_components)/,
       loader: 'babel-loader',
       options: { plugins: ['transform-class-properties']}
    }
 ]

Upvotes: 4

Muhammad Sulman
Muhammad Sulman

Reputation: 1681

Finally discovered, To remove this error in Laravel-Mix project, add below code in webpack.mix.js

mix.webpackConfig({
        module: {
            rules: [
                {
                    test: /\.js?$/,
                    exclude: /(node_modules|bower_components)/,
                    loaders: [
                        'babel-loader?presets[]=react,presets[]=es2015,presets[]=stage-0'
                    ]
                }
            ],
        }
});

Upvotes: 0

Jeff Tian
Jeff Tian

Reputation: 5893

I met the same problem using koa-react-view. Get inspired by these answers and finally fixed it with the following code in the koa server.js:

const register = require('babel-register');

register({
    presets: ['es2015', 'react', 'stage-0'],
    extensions: ['.jsx']
});

Upvotes: 0

Creem
Creem

Reputation: 141

I also meet this error because of the using of env presets: "presets": [ "react", "es2015", "stage-0", ["env", { "modules": false }]], and after I remove the env presets, it works well

Upvotes: 2

Ben
Ben

Reputation: 57267

I had this error because I was using stage-3 instead of stage-0.

Upvotes: 2

speak
speak

Reputation: 5382

OK, finally figured this out, in my webpack.config.js I had:

module: {
    loaders: [
      {
        test: /\.js?$/,
        exclude: /(node_modules|bower_components)/,
        loaders: [
          'react-hot',
          'babel?presets[]=react,presets[]=es2015,presets[]=stage-0'
        ]
      }
    ]
  }

'babel?presets[]=stage-0,presets[]=react,presets[]=es2015'

Has to be treated in the same way as .babelrc, switched stage-0 to be after es2015 and it compiles perfectly.

Upvotes: 65

Montage
Montage

Reputation: 29

@speak is right, but you need to change the order

loaders: [
  'react-hot',
  'babel?presets[]=react,presets[]=es2015,presets[]=stage-0'
]

Upvotes: 0

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