🐛 No dead code elimation in React

[maradotwebp]

Choose one: is this a 🐛 bug report or 🙋 feature request?
🐛 Bug

🎛 Configuration (.babelrc, package.json, cli command)

"scripts": {
    "start": "parcel index.html",
    "deploy": "parcel build index.html --public-url / && firebase deploy"
}

🤔 Expected Behavior

Expected dead code to be eliminated when building a React project in production mode.

😯 Current Behavior

Error in console:

Uncaught Error: React is running in production mode, but dead code elimination has not been applied. Read how to correctly configure React for production: https://fb.me/react-perf-use-the-production-build

💁 Possible Solution

Implement/Enable Tree Shaking.

🌍 Your Environment

Software	Version(s)
Parcel	1.4.1
Node	8.4.0
Yarn	1.3.2
Operating System	Windows 10

[DeMoorJasper]

duplicate of #392 We're planning to add tree shaking soon!