EventFlow.EventStores.EventStore 0.50.3124

• .NETFramework 4.6.2

  • EventFlow (>= 0.50.3124)
  • EventStore.Client (>= 4.0.0)

New: While EventFlow tries to limit the about of painful API changes, the
introduction of execution/command results are considered a necessary step
towards as better API.
Commands and command handlers have been updated to support execution
results. Execution results is meant to be an alternative to throwing domain
exceptions to do application flow. In short, before you were required to
throw an exception if you wanted to abort execution and "return" a failure
message.
The introduction of execution results changes this, as it allows
returning a failed result that is passed all the way back to the command
publisher. Execution results are generic and can thus contain e.g. any
validation results that a UI might need. The `ICommandBus.PublishAsync`
signature has changed to reflect this.
from
```csharp
Task<ISourceId> PublishAsync<TAggregate, TIdentity, TSourceIdentity>(
ICommand<TAggregate, TIdentity, TSourceIdentity> command)
where TAggregate : IAggregateRoot<TIdentity>
where TIdentity : IIdentity
where TSourceIdentity : ISourceId
```
to
```csharp
Task<TExecutionResult> PublishAsync<TAggregate, TIdentity, TExecutionResult>(
ICommand<TAggregate, TIdentity, TExecutionResult> command,
CancellationToken cancellationToken)
where TAggregate : IAggregateRoot<TIdentity>
where TIdentity : IIdentity
where TExecutionResult : IExecutionResult
```
Command handler signature has changed from
```csharp
Task ExecuteAsync(
TAggregate aggregate,
TCommand command,
CancellationToken cancellationToken);
```
to
```csharp
Task<TExecutionResult> ExecuteCommandAsync(
TAggregate aggregate,
TCommand command,
CancellationToken cancellationToken)
```
Migrating to the new structure should be seamless if your current code base
inherits its command handlers from the provided `CommandHandler<,,>` base
class.
Breaking: Source IDs on commands have been reworked to "make room" for
execution results on commands. The generic parameter from `ICommand<,,>`
and `ICommandHandler<,,,>` has been removed in favor of the new execution
results. `ICommand.SourceId` is now of type `ISourceId` instead of using
the generic type and the `ICommandBus.PublishAsync` no longer returns
`Task<ISourceId>`
To get code that behaves similar to the previous version, simply take the
`ISourceId` from the command, i.e., instead of this
```csharp
var sourceId = await commandBus.PublishAsync(command);
```
write this
```csharp
await commandBus.PublishAsync(command);
var sourceId = command.SourceId;
```
(`CancellationToken` and `.ConfigureAwait(false)` omitted fromt he above)
Breaking: Upgraded NuGet dependency on `RabbitMQ.Client` from `>= 4.1.3`
to `>= 5.0.1`