While working with any application, testing plays most important role. Data is main requirement for writing proper test cases. We need different kind of data to test complex features and here factories plays important role.
Data factory is blueprint that allows us to create an object, or a collection of objects, with predefined set of values. Factories makes it easy for us to define different kind of data.
In rails or ember we create model object to write test cases. In rails many of us use