Stratara.Testing.Orleans 4.4.4

Stratara.Testing.Orleans

Derived. The behaviour described here is specified under openspec/specs/. Those specifications are the source; this page explains and illustrates them.

Run the Orleans execution model in a test's own process. ExecutionModelTestHost starts one silo clustered with itself, with reminders and the grain directory in memory, and the framework's real write stack, portable commit-order reader, checkpoint store and intent store on an in-memory SQLite database. Every period the model keeps as a reminder or a poll is shortened to seconds, so a projection applies and a timer fires within a test. No cluster, no broker, no database server, no Docker.

Builds on Stratara.Testing.EntityFrameworkCore.

Why run the real grains?

Because the registration is what a test should prove. Your handlers, projections, sagas, processes and timer ports are registered with the calls production uses — AddStrataraAggregateGrains, AddStrataraProjectionGrains, AddStrataraSagaGrains, AddStrataraDurableTimers, AddStrataraOrleansCommandDispatcher — and run in the same grains, through the same mediator pipeline, reading the store in commit order from a checkpoint.

Example

await using var host = await ExecutionModelTestHost.CreateAsync(services => services
    .AddAggregatesFromAssemblyContaining<Account>()
    .AddCommandHandlersFromAssemblyContaining<OpenAccountHandler>()
    .AddProjectionsFromAssemblyContaining<BalanceProjection>()
    .AddStrataraAggregateGrains()
    .AddStrataraProjectionGrains());

await host.DispatchAsync(new OpenAccount(accountId, 100m));  // runs in the account's activation
await host.WaitForReadersAsync();                            // every reader is at the store's head

Assert.Equal(100m, balances[accountId]);

Contents

• ExecutionModelTestHost — CreateAsync(configure, options), DispatchAsync, WaitForReadersAsync, Timers, SeedAtHeadAsync, ResetAsync, the preset Session and Services. IAsyncDisposable.
• ExecutionModelTestHostOptions — the periods (PollInterval 250 ms, ReminderPeriod 1 s, IntentGrace 2 s, DrainPollingInterval 1 s), the partition count (4), the start timeout, and BeforeStart, which runs before the silo starts — where a test appends history and seeds the readers at its head, as a deployment does while no silo runs. A value a test sets through a registration's own settings wins over the host's.
• StrataraTestReadDbContext — the read context that holds the checkpoints.

Share a host across a test class

Creating a host takes a few seconds. Share one through a class fixture and reset it between tests where one must not see another's state:

public sealed class ExecutionModelFixture : IAsyncLifetime
{
    public ExecutionModelTestHost Host { get; private set; } = null!;

    public async ValueTask InitializeAsync() =>
        Host = await ExecutionModelTestHost.CreateAsync(services => services /* the roles */);

    public ValueTask DisposeAsync() => Host.DisposeAsync();
}

ResetAsync runs the execution model's reset port on this host, where the silo keeps running: the timers and the grain directory's entries go, and every registered reader is put at the store's head. The next test's facts are applied, the last test's are not applied a second time, and WaitForReadersAsync returns at once. The read models themselves are not emptied — empty or rebuild them in the fixture where a test needs them clean.

Where the host stops

• One silo. Membership, reminders and the directory are in memory and not shared. What happens across silos — a kill, a role split, a takeover — is an integration test against real infrastructure.
• Test projects only. Referencing the package from a project that is not a test project fails the build with STRATARA1001; StrataraAllowTestSupportOutsideTests=true opts out, as the sample does. CreateAsync refuses to run where DOTNET_ENVIRONMENT or ASPNETCORE_ENVIRONMENT states an environment other than Development.

Dependencies

• Stratara.Orleans, Stratara.Orleans.EntityFrameworkCore, Stratara.Testing.EntityFrameworkCore
• Microsoft.Orleans.Server, Microsoft.Extensions.Hosting