Now that we have a rough idea of how Jest works, it's time to start testing the various components of our Flux architecture. We'll start with action creator functions, since these determine the data that enters the system and are the starting point of the unidirectional data-flow. There are two types of action creators we'll want to test. First, we have the basic synchronous functions, followed by the asynchronous ones. Both types of actions lead to very different types of unit tests.
The job of an action creator is to create the necessary payload data and to dispatch it to stores. So to test this functionality, we'll want the real action creator function and a mocked dispatcher component. Remember, the idea is to isolate the component as the single unit that's being tested—we don't want any side-effects from the dispatcher code to influence the test outcome. With that said, lets take a look at the action creator:
import dispatcher from '../dispatcher...