This is the finished Tic Tac Toe tutorial from reactjs.org.

The main JSX code for this sample app is in site_modules/assets/_js/

That is linked to assets/_js/tic-tac-toe

The Game component is imported and rendered by assets/_js/react-app.jsx

Webpack is setup to compile the JSX starting with assets/_js/react-app.jsx as an entry point. See core/webpack.config.coffee and gulpfile.coffee

The template for this page (views/react-sample.pug) adds a script tag that links to /_js/react-app.js

That’s where WebPack either serves or writes the compiled JavaScript.

The CSS is in site_modules/assets/_css/

That is linked to assets/_css/tic-tac-toe