JS get hello world console.log

I built lora-app-server using Dockerflie-devel so when I modify ui/App.js outside of docker container by adding simply console.log("hello, World"); in render() function of ReactJS component I see changes inside in container:

bash-4.4# cat ui/src/App.js | grep console
    console.log("Hello, world!");

But I don’t see any changes in App.js in developer tools of browser:

What is the shortest workflow to get modified JS sources in browser?

cd ui
npm run build
cp -R build/* ../static/
cd ../

continue to shows me old main.xxx.js file in browser. But I am pretty sure i deleted old files bedore building new UI.

You need to execute make clean build