CQRS in Go — Part 1: the aggregate, Transition() and the Clone() you forget

CQRS in Go series: Part 1 : the aggregate, Transition() and Clone() Part 2 : command handlers without side effects Part 3 : sagas and event choreography Part 4 : PostgreSQL as an event store What an aggregate is The aggregate is the guardian of business consistency. It's the one that says "no" when an operation is invalid: you can't cancel an order that's already been shipped, you can't add an item to a closed cart. This logic lives in the aggregate and nowhere else. In Event Sourcing, the aggre