sane is the filesystem watcher used by jest-cli. It supports Linux, OS X, and Windows, and can use watchman if available. More notably, its dependency tree is significantly smaller than the dependency tree for chokidar.
Keep in mind that fsevents should only be required in OS X systems.
I played around with it for an hour or two and, for the most part, sane seemed to be able to take the place of chokidar without issue. Would something like this be considered?