A Suite of JavaScript libraries and framework extensions to help you
answer the question:
Does my application work in real life?
It's a big question, and it can't be answered with small tests that observe a tiny portion of your code that isn't integrated with any thing else. Big questions need big tests.
Bigtest is in the process of being extracted from several different projects and so it is very much in the "component pieces" phase. You can use these pieces in your own projects, but there is going to be some manual integration involved.
What does a big test look like?
The surest way to know if an application is going to work is to actually run it. Big tests boot the entire application before every testcase.
Does your appication run in a browser? Then if a test is going to measure whether it works or not, it also needs to run in a real browser that a real user might use, and it should dispatch real UI events against a real DOM.
Testing big is hard because there can be hundreds if not thousands of things happening concurrently inside your application; including user interactions.
Does your app make requests to an API? Then your tests should hammer the network too. Otherwise, you're measuring air.