UX: `ofType(..).matching(...)` uses predicates, could use assertions

[rradczewski]

The suggested use cases is as following:

1. Matching exactly one action dispatched to the store.

Given a test where exactly one action of $type is expected to be dispatched, we want to use an assertion-library to check whether the action matches. An action that does not match the assertion is considered a failure, possibly with a meaningful error message.

const store;
store.dispatch({type: 'IRRELEVANT'});
store.dispatch({type: 'FOO', payload: 3});

return expectRedux(store)
  .toDispatchAnAction()
  .ofType('FOO')
  .expectingExclusively(action => expect(action.payload).toEqual(3));

2. Matching one of the actions dispatched to the store using assertions

const store;
store.dispatch({type: 'IRRELEVANT'});
store.dispatch({type: 'FOO', payload: 3});

return expectRedux(store)
  .toDispatchAnAction()
  .ofType('FOO')
  .expecting(action => expect(action.payload).toEqual(3));

[rradczewski]

Went with 2. for 3.2.0