Babel

Create a .babelrc file in your project folder and add the following JSON with presets and plugins specified.

mern-simplesetup/.babelrc:

{
    "presets": [
      "env",
      "stage-2"
      "react"
    ],
    "plugins": [
      "react-hot-loader/babel"
    ]
}

The react-hot-loader/babel plugin is required by the react-hot-loader module to compile React components.