Removes scope ownership from EventStoreProjection. The class is now a
pure state machine — no Job, no AutoCloseable, no embedded
StateFlow:
class EventStoreProjection(store, filters, nowProvider) {
suspend fun seed() // run the seed query
fun apply(change: StoreChange): Boolean // apply one mutation
fun snapshot(): ProjectionState.Loaded // current view
}
ObservableEventStore.observe(filter, scope) is renamed to
ObservableEventStore.project(filter) and now returns a cold
Flow<ProjectionState<T>>. Each collection allocates its own state
machine, runs its own seed, and unsubscribes when the collector
cancels. The flow is built using channelFlow + the state machine —
the class stays as the load-bearing primitive.
Standard caller pattern:
val state = observable.project<TextNoteEvent>(filter)
.stateIn(viewModelScope, SharingStarted.WhileSubscribed(5_000),
ProjectionState.Loading)
Tradeoffs:
- Cold flow → multiple collectors each re-seed. ViewModel pattern
with stateIn shares one collection across observers (the standard
Android approach).
- close() goes away. Cancelling the collecting scope tears down the
projection.
- closeStopsListening test renamed to cancellingScopeStopsListening
and now verifies the StateFlow's value freezes after its scope is
cancelled.
17/17 projection + 240/240 store tests pass.
https://claude.ai/code/session_01Jny85MTu1ynKgFBgysfWu5
Claude
f789fe4f53