Add the babel-cli and babel-preset-es2015 (aka ES6) dependencies to your app’s package.json file and define a start script: { “dependencies”: { “babel-cli”: “^6.0.0”, “babel-preset-es2015”: “^6.0.0” }, “scripts”: { “start”: “babel-node –presets es2015 app.js” } } Then you can simply execute the following command to run your app: npm start If you ever decide to stop … Read more
For the client side code, you’re doing the correct thing. babelify it and ship it to the client. For the server side code, I would just do a regular build using babel-cli According to http://babeljs.io/docs/setup/#babel_register, babel-register is not meant for production use — The require hook is primarily recommended for simple cases. for Babel 6+ … Read more
moduleNameMapper is the setting that tells Jest how to interpret files with different extension. You need to tell it how to handle Less files. Create a file like this in your project (you can use a different name or path if you’d like): config/CSSStub.js module.exports = {}; This stub is the module we will tell … Read more
Create file called .babelrc in your root directory and add this code: { “presets”: [“next/babel”], “plugins”: [] } And in .eslintrc, replace the existing code with: { “extends”: [“next/babel”,”next/core-web-vitals”] }
From the babel 6 Release notes: Since Babel is focusing on being a platform for JavaScript tooling and not an ES2015 transpiler, we’ve decided to make all of the plugins opt-in. This means when you install Babel it will no longer transpile your ES2015 code by default. In my setup I installed the es2015 preset … Read more
This is related to compact option of Babel compiler, which commands to “not include superfluous whitespace characters and line terminators. When set to ‘auto’ compact is set to true on input sizes of >100KB.” By default its value is “auto”, so that is probably the reason you are getting the warning message. See Babel documentation. … Read more
In your .babelrc file, change { “presets”: [“env”] } to { “presets”: [“@babel/preset-env”] } (and install that package if you haven’t already). In your .babelrc you are still referencing the package babel-preset-env (which is for 6.x), you want to reference @babel/preset-env instead (which is for 7.x). https://github.com/babel/babel/issues/6186#issuecomment-366556833 Note: you should also make this change in … Read more
I was having the same failure (also using Babel, Typescript and Jest), it was driving me crazy for hours! Ended up creating a new babel.config.js file specifically for the tests. I had a large .babelrc that wasn’t getting picked up by jest no matter what I did to it. The main app still uses the … Read more
Since the React v16.0 release you can render an array of components without wrapping items in an extra element when you are inside a component: render() { return [ <li key=”one”>First item</li>, <li key=”two”>Second item</li>, <li key=”three”>Third item</li>, <li key=”four”>Fourth item</li>, ]; } Remember only to set the keys. UPDATE Now from the 16.2 version … Read more
Updated Answer: If you are using Babel 7.4.0 or newer, then @babel/polyfill has been deprecated. Instead, you will want to use the following at the top of your main js file (likely index.js or similar): import “core-js/stable”; import “regenerator-runtime/runtime”; Install these packages either with npm: npm install –save core-js npm install –save regenerator-runtime or with … Read more