Great breakdown of React changes here: https://github.com/facebook/react/blob/master/CHANGELOG.md#0140-october-7-2015 Due to deprecation warnings, I don't think this will break third-party extensions unless they were doing really bad things.
Summary: WIP Remove the mode prop from everywhere, use NylasEnv.isComposerWindow() instead Test Plan: Run updated tests Reviewers: drew, evan Reviewed By: evan Differential Revision: https://phab.nylas.com/D2766