It is easy to develop an abstraction over EventStore in order to work with Write side/domain in development phase. For tests just a FakeEventStore is needed and it is quite easy to have an InMemoryEventStore that could even start a complete working system.
But projections are another thing. How would you facilitate testing and working in development phase? Do you make only integration tests?
Is there any option low-cost that can have an “in-memory” abstraction that could allow for having a complete “development” working system without starting EventStore?