fake-promise
Gives full control over when ES6 promises are resolved by providing an implementation of Promise with behavior controlled by .resolve(result) and .reject(error) methods. Intended for use in unit tests.
mad-utils
A set of misc utilties I find myself repeatedly re-writing between projects.
react-test-wrapper
A set of classes to make setting up React components for unit tests easy.
floss
Unit-testing for those hard to reach places