facebook/react — pull request #294 by clayallsopp (2013-08-26 17:48:09+00:00)
Title: More helpful message if you update an unrendered component

We had a logic bug in our app where `replaceProps` was called before the component was `renderComponent`'d. The current error thrown is `Uncaught TypeError: Cannot read property 'constructor' of undefined `, which isn't super helpful.

Not sure this is the best/correct way to do this, but would love to know what is :)