[Solved]-Karma Coverage and Babel+Browserify Preprocessing-Reactjs

I had that same problem, which in my case occurred because React couldn't find the element in which it needed to render the html.

I found a quick fix by adding the following if statement into my main js file:

if ($('#container').length <= 0) {
  $('body').prepend('<div id="container"></div>');
}

ReactDom.render(
  <App />,
  document.getElementById('container')
);

I'm aware this must not be the best way of fixing it, but at least it works for now. If anyone knows of a better way, please let us know!

Code you are covering is trying to render component into DOM node. Your code relys that it already exists (somewhere in index.html or whatever). But PhantomJS cannot find that DOM node. You should create it before calling ReactDOM.render or search how to change template of html page used by phantom to run tests (there are plugins doung this).