Component.render() is silently swallowing errors with no console output

A piece of code in my render function is error-ing. A simple try/catch was able to capture and display the error, but without it React just silently proceeds by returning null in the render function and no error which makes it very difficult to find. Basically if the error happens, render fails silently and displays an empty component.

I am coming up with a JSFiddle to reprod in a simpler case for you to debug.

[gaearon]

@hurrtz

There is most likely nothing to fix in React. React is not catching any errors. The issue you’re seeing is most likely due to your call to setState being inside a Promise callback. When exception is thrown, your catch() handler might be swallowing it. Alternatively it may be possible that you don’t have a catch() handler, and Promise rejection stays unhandled, but your Promise polyfill might not log unhandled rejection. In this case I recommend changing the Promise polyfill.

If you’re sure it’s a problem with React then please help us by providing a case reproducing it. Thanks!

[samit4me]

Turn out it was a Promise eating the error. In the flux store triggered by a parent.