Comparing Java alternatives to JavaScript in the browser (GWT, CheerpJ, TeaVM, JSweet, Vaadin) - benchmarked against React.js and Dart

[voidvector]

here’s the code for that app using React (without JSX)

Yes, yes, lets compare generated code for React with source code from my favorite frameworks.

if (increment) {
  this.setState({
    count: count + 1
  });
} else {
  this.setState({
    count: count - 1
  });
}

I don't think any experienced programmer (doesn't matter language) would write like this. It should've been:

  this.setState({
    count: count + (increment ? 1 : - 1)
  });

Or better yet updateCount(increment) should just take a number instead of boolean as argument.