React.js转换问题。 Babel构建命令不起作用

Question

I have been following the react: up and running book by stoyan stephanov. Chapter 5. I am stuck at the command:

babel --presets react,es2015 js/source -d js/build

result: es2015 does not exist.

But when I try: babel --presets react js/source -d js/build

it works as expected in the book.

And then I write: babel --presets react,es2015 js/source -d js/build

result: Syntax error at app.js. Unexpected token before h1 tag.

App.js code

'use strict';

import React from 'react';
import ReactDOM from 'react-dom';
import Logo from './components/Logo';

ReactDOM.render(
  <h1>
    Welcome to the  app!
  </h1>,
  document.getElementById('app')
);

Answer 1

All optional presets must be installed manually, as far as I know:

npm install --save-dev babel-preset-es2015

PS Here are some additional data on issue.