referee is in your unit tests, deciding who passes and who fails.
It is a test-framework agnostic assertion and expectation library, designed to work with your choice of test runner. Some highlights:
- Rich library of assertions
 - Supports custom assertions
 - Complementary 
assert/refute(refuteis referee'sassert.not) - Evented: Emits success and failure events
 - Failing assertions throw exceptions by default, but can be configured to not
 - API to add custom assertions that provides quite a bit of plumbing for free
 - 100% test coverage (enforced with 
test-check-coverageinpackage.json) 
referee works in browsers (including old and rowdy ones, like IE11) and Node (LTS versions).
It will define itself as an AMD module if you want it to (i.e. if there's a
define function available).
https://sinonjs.github.io/referee/
Support us with a monthly donation and help us continue our activities. [Become a backer]
Become a sponsor and get your logo on our README on GitHub with a link to your site. [Become a sponsor]
referee was released under BSD-3