What is it?
Backbone.mock is not a "mock" library, it's a simple utility function, that allows you to map a Backbone.Model's url to an object that will be used as a response when using this model's instance fetch and save methods.
At one point I needed the ability to test "fake" ajax requests and this was the stupid and easy way I did it.
A jasmine spec is available to see example usage.
Improvements are welcome.