AggregateVerifier

Aggregate Verifier provides utilities for testing domain aggregates using the Given/When/Expect pattern.

This object facilitates setting up and executing tests for aggregate behavior by providing methods to create GivenStage instances. The Given/When/Expect pattern allows for declarative testing of command handling, event production, and state changes in domain aggregates.

Key features:

• Fluent API for test setup and verification

• Support for event sourcing and state-based aggregates

• Integration with in-memory event stores for isolated testing

• Dependency injection support via ServiceProvider

• Multi-tenant aggregate testing capabilities

Example usage:

aggregateVerifier<Cart, CartState>()
    .given(CartItemAdded(...))
    .whenCommand(AddCartItem(...))
    .expectEventType(CartItemAdded::class)
    .expectState { items.assert().hasSize(1) }
    .verify()