spread syntax doesn't work with node 6.10 - javascript

i am playing with spread syntax on node/browser.
console.log([{ name: "herry" }, { age: "10" }].reduce((acc, cur) => ({...cur,...acc})))
1) with nodejs v6.10,
SyntaxError: Unexpected token ...
2) Chrome 50
SyntaxError: Unexpected token ...
3) babel stage-0, it's working well.
I am just wandering why it's not working on node 6.10 since it's all green for spread op.
http://node.green/

To get this working:
yarn add -D babel-plugin-transform-object-rest-spread # (or the npm equivalent)
Then add "transform-object-rest-spread" to your .babelrc plugins e.g.
{
"presets": ["es2015"],
"plugins": ["transform-object-rest-spread"]
}

Related

Module parse failed: Unexpected token ? Optional chaining not recognised in threejs svgloader.js [duplicate]

Project setup:
Vuejs 3
Webpack 4
Babel
TS
We created the project using vue-cli and add the dependency to the library.
We then imported a project (Vue Currency Input v2.0.0) that uses optional chaining. But we get the following error while executing the serve script:
error in ./node_modules/vue-currency-input/dist/index.esm.js
Module parse failed: Unexpected token (265:36)
You may need an appropriate loader to handle this file type, currently no loaders are configured to process this file. See https://webpack.js.org/concepts#loaders
| getMinValue() {
| let min = this.toFloat(-Number.MAX_SAFE_INTEGER);
> if (this.options.valueRange?.min !== undefined) {
| min = Math.max(this.options.valueRange?.min, this.toFloat(-Number.MAX_SAFE_INTEGER));
| }
I read that Webpack 4 doesn't support optional chaining by default. So, we added the Babel plugin for optional chaining. This is our babel.config.js file:
module.exports = {
presets: ["#vue/cli-plugin-babel/preset"],
plugins: ["#babel/plugin-proposal-optional-chaining"],
};
(But, if I am correct, this plugin is now enable by default in the babel-preset. So this modification might be useless ^^)
One thing that I don't understand is that we can use optional chaining in the .vue files.
I created a SandBox with all the files: SandBox
How could I solve this error?
I was able to overcome this issue using #babel/plugin-proposal-optional-chaining, but for me the only way I could get Webpack to use the Babel plugin was to shove the babel-loader configuration through the Webpack options in vue.config.js. Here is a minimal vue.config.js:
const path = require('path');
module.exports = {
chainWebpack: config => {
config.module
.rule('supportChaining')
.test(/\.js$/)
.include
.add(path.resolve('node_modules/PROBLEM_MODULE'))
.end()
.use('babel-loader')
.loader('babel-loader')
.tap(options => ({ ...options,
plugins : ['#babel/plugin-proposal-optional-chaining']
}))
.end()
}
};
NB replace "PROBLEM_MODULE" in the above with the module where you have the problem.
Surprisingly I did not need to install #babel/plugin-proposal-optional-chaining with NPM. I did a go/no-go test with an app scaffolded with #vue/cli 4.5.13, in my case without typescript. I imported the NPM module that has been causing my grief (#vime/vue-next 5.0.31 BTW), ran the serve script and got the Unexpected token error on a line containing optional chaining. I then plunked the above vue.config.js into the project root and ran the serve script again, this time with no errors.
My point is it appears this problem can be addressed without polluting one's development environment very much.
The Vue forums are in denial about this problem, claiming Vue 3 supports optional chaining. Apparently not, however, in node modules. A post in this thread by atflick on 2/26/2021 was a big help.
Had same issue with Vue 2 without typescript.
To fix this you need to force babel preset to include optional chaining rule:
presets: [
[
'#vue/cli-plugin-babel/preset',
{
include: ['#babel/plugin-proposal-optional-chaining'],
},
],
],
Can also be achieved by setting old browser target in browserslist config.
Most importantly, you need to add your failing module to transpileDependencies in vue.config.js:
module.exports = {
...
transpileDependencies: ['vue-currency-input],
}
This is required, because babel by default will exclude all node_modules from transpilation (mentioned in vue cli docs), thus no configured plugins will be applied.
I had a similar problem. I'm using nuxt but my .babelrc file looks like the below, and got it working for me.
{
"presets": [
["#babel/preset-env"]
],
"plugins":[
["#babel/plugin-transform-runtime",
{
"regenerator": true
}
]
],
"env": {
"test": {
"plugins": [
["transform-regenerator", {
"regenerator": true
}],
"#babel/plugin-transform-runtime"
],
"presets": [
["#babel/preset-env", {
"useBuiltIns": false
}]
]
}
}
}
I managed to fix the solution by adding these lines to package.json:
...
"scripts": {
"preinstall": "npx npm-force-resolutions",
...
},
"resolutions": {
"acorn": "8.0.1"
},
...

Babel typescript unexpected token '?' in statement

Babel can't transform '?' in statement in typescript.
let t= getObject()?.fieldName;//Module build failed (from ./node_modules/babel-loader/lib/index.js): Unexpected token
let t= getObject() && getObejct().fieldName;
Maybe you can use optional-chaining
npm install --save-dev #babel/plugin-proposal-optional-chaining
add this in your babel file
{
"plugins": ["#babel/plugin-proposal-optional-chaining"]
}

Module not found: Error: Can't resolve 'crypto'

I am getting the following list of errors when I run ng serve.
My package JSON is as follows:
{ "name": "ProName", "version": "0.0.0", "scripts": {
"ng": "ng",
"start": "ng serve",
"build": "ng build",
"test": "ng test",
"lint": "ng lint",
"e2e": "ng e2e" }, "private": true, "dependencies": {
"#angular-devkit/build-angular": "~0.12.0",
"#angular/animations": "5.2.10",
"#angular/common": "5.2.10",
"#angular/compiler": "5.2.10",
"#angular/compiler-cli": "5.2.10",
"#angular/core": "5.2.10",
"#angular/forms": "5.2.10",
"#angular/platform-browser": "5.2.10",
"#angular/platform-browser-dynamic": "5.2.10",
"#angular/router": "5.2.10",
"#types/dotenv": "^4.0.3",
"#types/errorhandler": "0.0.32",
"#types/express": "^4.16.0",
"#types/node": "^10.5.1",
"apostille-library": "^7.1.0",
"core-js": "^2.5.4",
"dotenv": "^6.0.0",
"errorhandler": "^1.5.0",
"express": "^4.16.0",
"nem2-sdk": "^0.9.7",
"rxjs": "~6.3.3",
"stream": "0.0.2",
"tslib": "^1.9.0",
"typescript": "^2.9.2",
"zone.js": "~0.8.26" } }
The error I get :
ERROR in ./node_modules/aws-sign2/index.js Module not found: Error:
Can't resolve 'crypto' in
'/Users/MYPC/Documents/Myproj/ProName/node_modules/aws-sign2' ERROR in
./node_modules/aws4/aws4.js Module not found: Error: Can't resolve
'crypto' in '/Users/MYPC/Documents/Myproj/ProName/node_modules/aws4'
ERROR in ./node_modules/ecc-jsbn/index.js Module not found: Error:
Can't resolve 'crypto' in
'/Users/MYPC/Documents/Myproj/ProName/node_modules/ecc-jsbn' ERROR in
./node_modules/http-signature/lib/verify.js Module not found: Error:
Can't resolve 'crypto' in
'/Users/MYPC/Documents/Myproj/ProName/node_modules/http-signature/lib'
ERROR in ./node_modules/http-signature/lib/signer.js Module not found:
Error: Can't resolve 'crypto' in
'/Users/MYPC/Documents/Myproj/ProName/node_modules/http-signature/lib'
ERROR in ./node_modules/nem-sdk/build/external/nacl-fast.js Module not
found: Error: Can't resolve 'crypto' in
'/Users/MYPC/Documents/Myproj/ProName/node_modules/nem-sdk/build/external'
ERROR in ./node_modules/nem-sdk/node_modules/aws-sign2/index.js
I ran into a similar issue lately while trying to use another library (tiff.js) in a small project I was experimenting with.
The way I got around this was to add the following to my package.json file, right after the devDependencies section.
"devDependencies": {
...
},
"browser": {
"crypto": false
}
This didn't seem to have any adverse effect when trying to use the library in the application.
Adding this setting in tsconfig.json file under that project resolve this warning
"compilerOptions": {
"baseUrl": "./",
"paths": {
"crypto": [
"node_modules/crypto-js"
]
}
I like R. Richards's answer, but I thought it would be useful to provide some more information.
This is a known issue with Angular, and the Angular CLI dev team seems to think it's a feature rather than a bug. I, as well as other developers in this issue thread, disagree. Contributors to that thread provided several workaround fixes, but my project didn't compile successfully until I implemented R. Richards' solution. I didn't revert the previous changes, though, so tacnoman's and GrandSchtroumpf's fixes may be of use to others.
Some, like clovis1122 here and others in that issue thread, have questioned why a web app would need access to these libraries and why the necessary tasks can't be completed on the server side instead. I can't speak for everyone, but my use case is that, when authenticating a user account, Strapi responds with a JSON Web Token string that must be decoded by the client. Since the necessary library depends on crypto and stream, you won't be able to extract the JWT expiration time unless those dependencies are available.
In case anyone has trouble extrapolating from R. Richards' answer, you'll have to set to false any dependencies that are showing up in "can't resolve x" errors. For example, the critical part of my package.json is:
"browser": {
"crypto": false,
"stream": false
}
I thought I would expand on what Tarique Ahmed wrote in his answer.
I was using an npm module that had the following line in the code:
const crypto = require('crypto');
I couldn't add:
"browser": {
"crypto": false
}
to the package.json because the crypto package had to be part of the build.
It turns out that during the compilation process Angular seems to have decided to install the crypto-browserify package instead of crypto.
Adding the following to the tsconfig.json file instructs the build to use the crypto-browserify library every time that crypto is required. As you can see, I had the same issue for the stream package.
"paths": {
"crypto": [
"node_modules/crypto-browserify"
],
"stream": [
"node_modules/stream-browserify"
]
}
After having the same issue with Angular 11 and crypto-js 4 (and manually setting the path in tsconfig.json), I found rolling back crypto-js to version 3.1.9-1 fixed the issue. It seems a change made in version 4 caused the issue.
npm install crypto-js#3.1.9-1
Explained here in repo issues:
GitHub issue
If you upgraded to Webpack 5, you need to add this to your webpack config file:
resolve: {
fallback: { crypto: false },
},
aws-sign2 is a NodeJS package (and crypto is a NodeJS module), but it looks like you're dealing with a web application. It makes sense that the crypto module is not available in that environment.
Would it be possible to complete what you need to do server-side? Otherwise, you may need to look for another package.
For Laravel Inertia JS project, my solution was:
1- Add dependencies to package.json
"dependencies": {
"crypto-browserify": "3.12.0",
"crypto-random-string": "^3.3.0",
"stream": "^0.0.2"
}
2-In webpack.config.js:
const path = require('path');
module.exports = {
resolve: {
alias: {
'#': path.resolve('resources/js'),
},
fallback: {
crypto: require.resolve('crypto-browserify'),
stream: require.resolve('stream'),
},
},
};
3-Install, build and run:
npm install && npm run watch
I have resolved my issue using below steps:
Add below to tsconfig.json to resolve crypto warning:
"paths": {
"crypto": [
"node_modules/crypto-js"
]
},
and add below to angular.json
"options": {
"allowedCommonJsDependencies": [
"crypto-js"
],
...
}
My Error
In my Case the import { get } from "express/lib/response" is the culprit, which is automatically added by vs-code.
So, after removing it I solved my issue
When using #Laravel framework with Laravel Mix this is going to be more trick. I spend some hours on this NPM nightmare and found a solid solution.
So, in your webpack.mix.js you find the 'comment'
/*
|--------------------------------------------------------------------------
| Mix Asset Management
|--------------------------------------------------------------------------
|
| Mix provides a clean, fluent API for defining some Webpack build steps
| for your Laravel application. By default, we are compiling the Sass
| file for the application as well as bundling up all the JS files.
|
*/
Now just below that comment add the following lines;
mix.webpackConfig(webpack => {
return {
plugins: [
new webpack.LoaderOptionsPlugin({
exports: {
resolve: {
fallback: {
crypto: require.resolve('crypto-browserify'),
}
}
}
})
]
};
});
Now you can use Laravel Mix just like you would edit webpack.config.js ;)
Also; In package.json remove:
--no-progress --hide-modules
These are no longer valid for WebPack >= 5. Enjoy!
After a deep a research i found that the solution is very simple: replace
import * as CryptoJS from 'crypto-js'; with declare var CryptoJS;
Using direct import may not work with ES6 Enviornment..
This may help you.
$ npm i crypto-js#latest // For using latest version 4
import AES from 'crypto-js/aes';
import Utf8 from 'crypto-js/enc-utf8';
import { secretKey } from './environments/environment';
/** Encryption */
const data = {key: 'Test Value'};
const ciphertext = AES.encrypt(JSON.stringify(data), secretKey).toString();
console.log('Encrypted Data', ciphertext);
/** Decryption */
const bytes = AES.decrypt(ciphertext, secretKey);
const decryptedData = JSON.parse(bytes.toString(Utf8));
console.log('Decrypted Data', decryptedData);
https://github.com/brix/crypto-js/issues/168#issuecomment-785617218
Add the option allowedCommonJsDependencies with literal "crypto-js" in a array, this in file angular.json:
"architect":
"build": {
"options": {
"allowedCommonJsDependencies": [
"crypto-js"
]
},
}
}
This will disable all warnings, tested in Angular 11.
My problem was that I was trying to build to node and web using the same code, but is not possible to built to web while importing a WebSocket dependency, ws in my case
So the solution is by using a wrapper:
Install a wrapper, I will use isomorphic-ws because is made for ws
npm i --save isomorphic-ws
Remove const WebSocket = require('ws')
Replace with:
const WebSocket = require('isomorphic-ws')
I ended up going into
node_modules/react-scripts/config/webpack.config.js
and adding:
fallback: {
// Here paste
crypto: require.resolve("crypto-browserify"),
https: require.resolve("https-browserify"),
http: require.resolve("stream-http"),
url : require.resolve("url")
}
And now my react app builds with errors but no dependency issues. Ill update this when I get it building.
Add
npm install crypto-js
Or Add a specific version according to your project need
npm install crypto-js#4.0.0
Also, run the above commands in Window "run as administrator" or in Linux use sudo
Alot of answers already but still none of them works. In my case I see warning message
BREAKING CHANGE: webpack < 5 used to include polyfills for node.js core modules by default. This is no longer the case. Verify if you need this module and configure a polyfill for it. If you want to include a polyfill, you need to: - add a fallback 'resolve.fallback: { "crypto": require.resolve("crypto-browserify") }' - install 'crypto-browserify' If you don't want to include a polyfill, you can use an empty module like this: resolve.fallback: { "crypto": false }
comment from #stewii did helped me to resolved this.
There is now an ES modules version called "crypto-es". It clears these warnings. npmjs.com/package/crypto-es
After this I imported cryptoES
import CryptoES from 'crypto-es';
and remove the existing import of cryptoJs. Re-start the compile and Voila.. The warning message is gone.
I tried a lot of the solutions above but the final thing that worked for me was downloading the crypto-es package and adding, "type":"module" to package.json.
https://www.npmjs.com/package/crypto-es
I was facing same issue, Just run node patch.js and it worked. The issue is, browser doesn't allow server files to be run on browser. In case you need some of these, You can use node patch.js. If you don't want to run any server file on browser, you can simply apply above mentioned solution by #R.Richards. Might be helpful for someone..
In my case, the solution described by R.Richards doesn't work.
However, following several threads along this issue, I finally understood where to insert the recommendation provided in the warning message and solved this warning.
WARNING in ./node_modules/bcryptjs/dist/bcrypt.js 64:13-45
Module not found: Error: Can't resolve 'crypto' in 'C:\PC\Documents\3 - Projet MAKAO\dev\RepoAlecol\node_modules\bcryptjs\dist'
BREAKING CHANGE: webpack < 5 used to include polyfills for node.js core modules by default.
This is no longer the case. Verify if you need this module and configure a polyfill for it.
**If you want to include a polyfill, you need to:
- add a fallback 'resolve.fallback: { "crypto": require.resolve("crypto-browserify") }'
- install 'crypto-browserify'
If you don't want to include a polyfill, you can use an empty module like this:
resolve.fallback: { "crypto": false }**
Differently from many contributors, I didn't want to install crypto-browserify as I don't need it (*), and I chose to add the fallback { "crypto": false }.
However I didn't know where to add this fallback. After reading several threads, I found it was in the webpack.config.js file, which is located in the directory node_modules/react_scripts/config.
Adding this fallback made the compilation succeed without any warning.
(*) PS : I once tried to add the following fallback { "crypto": require.resolve("crypto-browserify") }, but it led to generation of 7 errors, requiring other modules :
Failed to compile.
Module not found: Error: Can't resolve 'stream' in 'C:\PC\Documents\3 - Projet MAKAO\dev\RepoAlecol\node_modules\cipher-base'
BREAKING CHANGE: webpack < 5 used to include polyfills for node.js core modules by default.
This is no longer the case. Verify if you need this module and configure a polyfill for it.
If you want to include a polyfill, you need to:
- add a fallback 'resolve.fallback: { "stream": require.resolve("stream-browserify") }'
- install 'stream-browserify'
If you don't want to include a polyfill, you can use an empty module like this:
resolve.fallback: { "stream": false }
ERROR in ./node_modules/cipher-base/index.js 2:16-43
Module not found: Error: Can't resolve 'stream' in 'C:\PC\Documents\3 - Projet MAKAO\dev\RepoAlecol\node_modules\cipher-base'
BREAKING CHANGE: webpack < 5 used to include polyfills for node.js core modules by default.
This is no longer the case. Verify if you need this module and configure a polyfill for it.
If you want to include a polyfill, you need to:
- add a fallback 'resolve.fallback: { "stream": require.resolve("stream-browserify") }'
- install 'stream-browserify'
If you don't want to include a polyfill, you can use an empty module like this:
resolve.fallback: { "stream": false }
ERROR in ./node_modules/readable-stream/lib/_stream_readable.js 43:13-37
Module not found: Error: Can't resolve 'buffer' in 'C:\PC\Documents\3 - Projet MAKAO\dev\RepoAlecol\node_modules\readable-stream\lib'
BREAKING CHANGE: webpack < 5 used to include polyfills for node.js core modules by default.
This is no longer the case. Verify if you need this module and configure a polyfill for it.
If you want to include a polyfill, you need to:
- add a fallback 'resolve.fallback: { "buffer": require.resolve("buffer/") }'
- install 'buffer'
If you don't want to include a polyfill, you can use an empty module like this:
resolve.fallback: { "buffer": false }
ERROR in ./node_modules/readable-stream/lib/_stream_writable.js 65:13-37
Module not found: Error: Can't resolve 'buffer' in 'C:\PC\Documents\3 - Projet MAKAO\dev\RepoAlecol\node_modules\readable-stream\lib'
BREAKING CHANGE: webpack < 5 used to include polyfills for node.js core modules by default.
This is no longer the case. Verify if you need this module and configure a polyfill for it.
If you want to include a polyfill, you need to:
- add a fallback 'resolve.fallback: { "buffer": require.resolve("buffer/") }'
- install 'buffer'
If you don't want to include a polyfill, you can use an empty module like this:
resolve.fallback: { "buffer": false }
ERROR in ./node_modules/readable-stream/lib/internal/streams/buffer_list.js 63:15-32
Module not found: Error: Can't resolve 'buffer' in 'C:\PC\Documents\3 - Projet MAKAO\dev\RepoAlecol\node_modules\readable-stream\lib\internal\streams'
BREAKING CHANGE: webpack < 5 used to include polyfills for node.js core modules by default.
This is no longer the case. Verify if you need this module and configure a polyfill for it.
If you want to include a polyfill, you need to:
- add a fallback 'resolve.fallback: { "buffer": require.resolve("buffer/") }'
- install 'buffer'
If you don't want to include a polyfill, you can use an empty module like this:
resolve.fallback: { "buffer": false }
ERROR in ./node_modules/ripemd160/index.js 3:13-37
Module not found: Error: Can't resolve 'buffer' in 'C:\PC\Documents\3 - Projet MAKAO\dev\RepoAlecol\node_modules\ripemd160'
BREAKING CHANGE: webpack < 5 used to include polyfills for node.js core modules by default.
This is no longer the case. Verify if you need this module and configure a polyfill for it.
If you want to include a polyfill, you need to:
- add a fallback 'resolve.fallback: { "buffer": require.resolve("buffer/") }'
- install 'buffer'
If you don't want to include a polyfill, you can use an empty module like this:
resolve.fallback: { "buffer": false }
ERROR in ./node_modules/safe-buffer/index.js 3:13-30
Module not found: Error: Can't resolve 'buffer' in 'C:\PC\Documents\3 - Projet MAKAO\dev\RepoAlecol\node_modules\safe-buffer'
BREAKING CHANGE: webpack < 5 used to include polyfills for node.js core modules by default.
This is no longer the case. Verify if you need this module and configure a polyfill for it.
If you want to include a polyfill, you need to:
- add a fallback 'resolve.fallback: { "buffer": require.resolve("buffer/") }'
- install 'buffer'
If you don't want to include a polyfill, you can use an empty module like this:
resolve.fallback: { "buffer": false }
ERROR in ./node_modules/safer-buffer/safer.js 5:13-30
Module not found: Error: Can't resolve 'buffer' in 'C:\PC\Documents\3 - Projet MAKAO\dev\RepoAlecol\node_modules\safer-buffer'
BREAKING CHANGE: webpack < 5 used to include polyfills for node.js core modules by default.
This is no longer the case. Verify if you need this module and configure a polyfill for it.
If you want to include a polyfill, you need to:
- add a fallback 'resolve.fallback: { "buffer": require.resolve("buffer/") }'
- install 'buffer'
If you don't want to include a polyfill, you can use an empty module like this:
resolve.fallback: { "buffer": false }
webpack compiled with 7 errors
I had this problem in ReactJS with create-react-app(facebook)
Solution:
First install the necessary packages "crypto-browserify"
Modify webpack.config.js in reactjs with create-react-app this file is inside:
node_modules/react-scripts/config/webpack.config.js
Search module.exports and inside this function there is a return:
module.exports = function (webpackEnv) {
...
return {
...
resolve: {
...
fallback: {
// Here paste
crypto: require.resolve("crypto-browserify"),
}
}
}
}
Note: Is possible you need other packages how "stream-browserify" the steps are same. This solution works, but when the webpack project starts it shows warnings
Pd: I am not native speaker English, but I hope understand me.

Babel - regeneratorRuntime is not defined, when using transform-async-to-generator plugin

I am not able to setup babel correctly for the usage of async / await.
I am using babel 7 and webpack 4.
I do not want to use babel-polyfill if possible!
My babelrc file:
{
"presets": [[
"#babel/env",
{"modules": false}
]],
"plugins": [
"syntax-dynamic-import",
"transform-async-to-generator"
]
}
Code:
async function init() {
const loaderData = await initLoader();
initCmp(loaderData)
.then(initApi(loaderData.key))
.catch();
}
init();
And Error:
refactor.main.js:18 Uncaught ReferenceError: regeneratorRuntime is not defined
at eval (refactor.main.js:18)
at eval (refactor.main.js:47)
at Object../client/refactor.main.js (cmp.bundle.js:312)
at __webpack_require__ (cmp.bundle.js:62)
at eval (main.js:6)
at Object../client/main.js (cmp.bundle.js:300)
at __webpack_require__ (cmp.bundle.js:62)
at cmp.bundle.js:179
at cmp.bundle.js:182
The latest documentation here is pretty clear:
https://babeljs.io/docs/en/next/babel-plugin-transform-runtime
What worked for me is installing the two packages for build and for runtime (the final script for the browser):
npm install --save-dev #babel/plugin-transform-runtime
npm install --save #babel/runtime
In the plugin Array of my webpack configuration I just added '#babel/plugin-transform-runtime' without any options. (Please also have a look at the documentation linked above, since some options (that you might find in older tutorials or answers) have been removed.)
plugins: [
'#babel/plugin-transform-runtime'
]
I now can use async functions without errors, and it didn't add much code in the production build.
You also need the transform-runtime plugin, so your .babelrc should ready:
{
"presets": [[
"#babel/env",
{"modules": false}
]],
"plugins": [
"syntax-dynamic-import",
"transform-runtime",
"transform-async-to-generator"
]
}
Note that you'll also need to npm install --save-dev transform-runtime

How to fix 'Module build failed: SyntaxError: Missing class properties transform.'?

In my reactjs component I have this code:
increment = () => {
store.dispatch({type: 'INC'});
}
When I run npm start in the console I get:
Module build failed: SyntaxError: Missing class properties transform.
I installed :
npm install --save-dev babel-plugin-transform-class-properties
And also added this to my .babelrc :
"plugins": [
"transform-class-properties"
],
"presets": [
"es2015",
"react",
"stage-0"
],
How can I resolve this?
Have you seen this other post: Error: Missing class properties transform ?
I had a similar problem, and, as one of the comments on the accepted answer above suggests, I had the presets listed in both my .babelrc file and my webpack.config. I removed the redundant options from my webpack.config and now it runs.

Categories