public async Task OnError_Continue_prevents_aggregator_exceptions_from_stopping_catchup()
{
var count = 0;
var projectionStore = new InMemoryProjectionStore <BalanceProjection>();
var projector = new BalanceProjector()
.Pipeline(async(projection, batch, next) =>
{
Interlocked.Increment(ref count);
if (count < 20)
{
throw new Exception("oops");
}
await next(projection, batch);
}).Trace();
var catchup = StreamCatchup.All(streamSource.StreamPerAggregate().Trace(),
batchSize: 50);
catchup.Subscribe(projector,
projectionStore.AsHandler(),
onError: e => e.Continue());
await catchup.RunSingleBatch();
projectionStore.Count().Should().Be(31);
}
public async Task OnError_Continue_prevents_aggregator_exceptions_from_stopping_catchup()
{
var projectionStore = new InMemoryProjectionStore <BalanceProjection>();
var count = 0;
var projector = new BalanceProjector()
.Pipeline(async(projection, batch, next) =>
{
Interlocked.Increment(ref count);
Console.WriteLine(count);
if (count < 49)
{
Throw();
}
await next(projection, batch);
}).Trace();
var catchup = StreamCatchup.Create(stream.Trace(),
batchSize: 50);
catchup.Subscribe(projector,
projectionStore.AsHandler(),
onError: e => e.Continue());
await catchup.RunUntilCaughtUp();
projectionStore.Count().Should().Be(1);
projectionStore.Single().CursorPosition.Should().Be(1);
}
public async Task When_one_projection_fails_its_cursor_is_not_advanced_while_other_projections_cursors_are_advanced()
{
var projections = new InMemoryProjectionStore <BalanceProjection>();
// first catch up all the projections
var stream = streamSource.StreamPerAggregate().Trace();
var catchup = StreamCatchup.All(stream);
var initialSubscription = catchup.Subscribe(new BalanceProjector(), projections);
await catchup.RunUntilCaughtUp();
initialSubscription.Dispose();
// write some additional events
var streamIdsWithoutErrors = streamIds.Take(5).ToList();
var streamIdsWithErrors = streamIds.Skip(5).Take(5).ToList();
foreach (var streamId in streamIdsWithoutErrors.Concat(streamIdsWithErrors))
{
store.WriteEvents(streamId, howMany: 10);
}
// subscribe a flaky projector
catchup.Subscribe(new BalanceProjector()
.Pipeline(async(projection, batch, next) =>
{
var aggregateId = batch.Select(i => i.AggregateId).First();
if (streamIdsWithErrors.Contains(aggregateId))
{
throw new Exception("oops");
}
await next(projection, batch);
}),
projections.AsHandler(),
e => e.Continue());
await catchup.RunSingleBatch();
var projectionsWithoutErrors = streamIdsWithoutErrors.Select(
id => projections.Get(id).Result);
var projectionsWithErrors = streamIdsWithErrors.Select(
id => projections.Get(id).Result);
foreach (var projection in projectionsWithoutErrors)
{
projection.CursorPosition.Should().Be(11);
projection.Balance.Should().Be(11);
}
foreach (var projection in projectionsWithErrors)
{
projection.CursorPosition.Should().Be(1);
projection.Balance.Should().Be(1);
}
}
public async Task When_an_aggregation_fails_then_the_projection_is_not_updated()
{
var projections = new InMemoryProjectionStore <BalanceProjection>();
var catchup = StreamCatchup.All(streamSource.StreamPerAggregate().Trace());
// subscribe a flaky projector
catchup.Subscribe(new BalanceProjector()
.Pipeline(async(projection, batch, next) =>
{
bool shouldThrow = true; // declared outside to nudge the compiler into inferring the correct .Pipeline overload
if (shouldThrow)
{
throw new Exception("oops");
}
await next(projection, batch);
}),
projections.AsHandler(),
e => e.Continue());
await catchup.RunSingleBatch();
projections.Count().Should().Be(0);
}
public async Task When_an_aggregation_fails_then_the_projection_is_not_updated()
{
var projections = new InMemoryProjectionStore<BalanceProjection>();
var catchup = StreamCatchup.All(streamSource.StreamPerAggregate().Trace());
// subscribe a flaky projector
catchup.Subscribe(new BalanceProjector()
.Pipeline(async (projection, batch, next) =>
{
bool shouldThrow = true; // declared outside to nudge the compiler into inferring the correct .Pipeline overload
if (shouldThrow)
{
throw new Exception("oops");
}
await next(projection, batch);
}),
projections.AsHandler(),
e => e.Continue());
await catchup.RunSingleBatch();
projections.Count().Should().Be(0);
}
public async Task OnError_Continue_prevents_aggregator_exceptions_from_stopping_catchup()
{
var projectionStore = new InMemoryProjectionStore<BalanceProjection>();
var count = 0;
var projector = new BalanceProjector()
.Pipeline(async (projection, batch, next) =>
{
Interlocked.Increment(ref count);
Console.WriteLine(count);
if (count < 49)
{
Throw();
}
await next(projection, batch);
}).Trace();
var catchup = StreamCatchup.Create(stream.Trace(),
batchCount: 50);
catchup.Subscribe(projector,
projectionStore.AsHandler(),
onError: e => e.Continue());
await catchup.RunUntilCaughtUp();
projectionStore.Count().Should().Be(1);
projectionStore.Single().CursorPosition.Should().Be(1);
}
public async Task OnError_Continue_prevents_aggregator_exceptions_from_stopping_catchup()
{
var count = 0;
var projectionStore = new InMemoryProjectionStore<BalanceProjection>();
var projector = new BalanceProjector()
.Pipeline(async (projection, batch, next) =>
{
Interlocked.Increment(ref count);
if (count < 20)
{
throw new Exception("oops");
}
await next(projection, batch);
}).Trace();
var catchup = StreamCatchup.All(streamSource.StreamPerAggregate().Trace(),
batchSize: 50);
catchup.Subscribe(projector,
projectionStore.AsHandler(),
onError: e => e.Continue());
await catchup.RunSingleBatch();
projectionStore.Count().Should().Be(31);
}
public async Task When_one_projection_fails_its_cursor_is_not_advanced_while_other_projections_cursors_are_advanced()
{
var projections = new InMemoryProjectionStore<BalanceProjection>();
// first catch up all the projections
var stream = streamSource.StreamPerAggregate().Trace();
var catchup = StreamCatchup.All(stream);
var initialSubscription = catchup.Subscribe(new BalanceProjector(), projections);
await catchup.RunUntilCaughtUp();
initialSubscription.Dispose();
// write some additional events
var streamIdsWithoutErrors = streamIds.Take(5).ToList();
var streamIdsWithErrors = streamIds.Skip(5).Take(5).ToList();
foreach (var streamId in streamIdsWithoutErrors.Concat(streamIdsWithErrors))
{
store.WriteEvents(streamId, howMany: 10);
}
// subscribe a flaky projector
catchup.Subscribe(new BalanceProjector()
.Pipeline(async (projection, batch, next) =>
{
var aggregateId = batch.Select(i => i.AggregateId).First();
if (streamIdsWithErrors.Contains(aggregateId))
{
throw new Exception("oops");
}
await next(projection, batch);
}),
projections.AsHandler(),
e => e.Continue());
await catchup.RunSingleBatch();
var projectionsWithoutErrors = streamIdsWithoutErrors.Select(
id => projections.Get(id).Result);
var projectionsWithErrors = streamIdsWithErrors.Select(
id => projections.Get(id).Result);
foreach (var projection in projectionsWithoutErrors)
{
projection.CursorPosition.Should().Be(11);
projection.Balance.Should().Be(11);
}
foreach (var projection in projectionsWithErrors)
{
projection.CursorPosition.Should().Be(1);
projection.Balance.Should().Be(1);
}
}
