I’ve begun looking at building a project using React and followed some online sources to begin with. But then I fell into outdated material that related to babel. So I could only take many of the tutorials so far before having to update the construction to suit @babel/core v7.

It seems it’s very easy to install different versions of babel and it’s components and then discover things won’t compile. The error message I was getting:

Error: Plugin/Preset files are not allowed to export objects, only functions.

It doesn’t exactly make clear that what you have probably done is installed a preset  from an older version of babel and your babel core doesn’t like it.

I then took to building a bare bones “Hello World” project to use as a re-usable react and webpack template.

Steps to follow

Create your project folder

$ mkdir ~/myproject
$ cd ~/myproject

Initialise your package.json using yarn or npm. Set your entry point to ./client/index.js

$ yarn init

Add the dependencies

$ yarn add react react-dom

Add the devDependencies

$ yarn add @babel/core @babel/preset-env @babel/preset-react babel-loader html-webpack-plugin webpack webpack-cli webpack-dev-server -D

Edit your package.json so it should look something like this:

{
  "name": "react",
  "version": "0.1.0",
  "description": "React / Webpack template",
  "main": "./client/index.js",
  "author": "Warlord",
  "license": "GPL-3.0",
  "private": false,
  "scripts": {
    "start": "webpack-dev-server"
  },
  "dependencies": {
    "react": "^16.5.2",
    "react-dom": "^16.5.2"
  },
  "devDependencies": {
    "@babel/core": "^7.1.0",
    "@babel/preset-env": "^7.1.0",
    "@babel/preset-react": "^7.0.0",
    "babel-loader": "^8.0.2",
    "html-webpack-plugin": "^3.2.0",
    "webpack": "^4.19.1",
    "webpack-cli": "^3.1.0",
    "webpack-dev-server": "^3.1.8"
  }
}

Notice the scripts section has been added to start the webpack dev server.

You could get a bit more adventurous and add a dev and prod script to either run the webpack dev server or compile into the dist folder using webpack -p for production minified assets.

Create a .babelrc file in the project root. This is babels configuration file and this is where you tell babel what presets to use. It’s also where the tutorials made me fail because I was using “react” and not “@babel/preset-react”.

{
  "presets":[
    "@babel/preset-env", "@babel/preset-react"
  ]
}

Create a client and dist folder in your project with the following structure and files:

client
  +-- components
      App.js
  index.html
  index.js
dist

Running yarn start should serve on port 8080 and you can visit your page at http://localhost:8080

The example files used are in the gist below.

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