public async Task ItShouldStartWithNewSnapshot()
{
_snapshots
.Load <Shopping>("customerId", "messageId")
.Returns(Task.FromResult(new Snapshot(
-1,
"customerId",
new Shopping()
)));
_events
.Load <Shopping>("customerId", "messageId", -1)
.Returns(new Envelope[0].ToAsync());
await _events
.Append <Shopping>(Arg.Do <IEnumerable <Envelope> >(envelopes => {
var first = envelopes.First();
first.Sequence.ShouldBe(0);
((ProductChosen)first.Message).ShouldNotBeNull();
((ProductChosen)first.Message).CustomerId.ShouldBe("customerId");
((ProductChosen)first.Message).ProductId.ShouldBe("productId");
}));
await _snapshots
.Save <Shopping>(Arg.Do <Snapshot>(snapshot => {
snapshot.Sequence.ShouldBe(0);
snapshot.Identity.ShouldBe("customerId");
snapshot.Snap.ShouldBeOfType <Shopping>();
}));
await new CommandHandler <Shopping>(_events, _snapshots, "customerId")
.Handle(new ChooseProduct("customerId", "productId"), "messageId");
}
public async Task Handle(object cmd, string messageId = null)
{
if (null == _snapshot)
{
_snapshot = await _snapshots.Load <TInvariant>(_identity, messageId);
await foreach (var envelope in _events.Load <TInvariant>(_identity, messageId, _snapshot.Sequence))
{
_snapshot.Sequence++;
_snapshot.Snap = ((IArrange <TInvariant>)_snapshot.Snap).Arrange(envelope.Message);
}
}
_snapshot.Snap = await((IAct <TInvariant>)_snapshot.Snap).Act(cmd);
var envelopes = ((IAct <TInvariant>)_snapshot.Snap)
.Commit()
.Select((evt, i) => new Envelope(
_identity,
typeof(TInvariant).Name,
++_snapshot.Sequence,
evt
).CausedBy(messageId ?? Guid.NewGuid().ToString()))
.ToArray();
if (!envelopes.Any())
{
return;
}
await _events.Append <TInvariant>(envelopes);
await _snapshots.Save <TInvariant>(_snapshot);
}
