Build a little string you can eval to test if a JS runtime is ready to run caffeine-script generated code without transpiling.
Try now: https://caffeine-suite.github.io/caffeine-script-compatibility-test/
npm install caffeine-script-compatibility-test
CaffeineScript uses a subset of ES6's capabilities. This tool lets you see if a browser would be fully supported without transpiling with a tool like Babel. Of course you can always use Babel to get compatility on older browers.