Worker test hooks

Polling loops often lead to slow tests built around arbitrary delays. GUSTO exposes two static barriers on JobQueueWorker<TRecord> so a test can control one batch cycle.

[Fact]
public async Task Worker_executes_an_enqueued_job()
{
    var started = new TaskCompletionSource(
        TaskCreationOptions.RunContinuationsAsynchronously);
    var completed = new TaskCompletionSource(
        TaskCreationOptions.RunContinuationsAsynchronously);

    JobQueueWorker<JobRecord>.BatchStartBarrier = started;
    JobQueueWorker<JobRecord>.BatchCompletedBarrier = completed;

    try
    {
        await queue.EnqueueAsync<ExampleJobs>(jobs => jobs.DoWorkAsync("test"));

        await hostedService.StartAsync(CancellationToken.None);
        started.SetResult();
        await completed.Task.WaitAsync(TimeSpan.FromSeconds(5));

        Assert.True(provider.WasCompleted);
    }
    finally
    {
        await hostedService.StopAsync(CancellationToken.None);
        JobQueueWorker<JobRecord>.BatchStartBarrier = null;
        JobQueueWorker<JobRecord>.BatchCompletedBarrier = null;
    }
}

BatchStartBarrier pauses before polling. BatchCompletedBarrier is signaled after the complete batch cycle, including an empty poll. Each barrier is cleared by the worker after use.

Isolate barrier tests

The barriers are static per record type. Tests using the same TRecord can interfere if they run in parallel. Put them in a non-parallel test collection or use a distinct record type per fixture.

Always put an upper bound around waiting and clear barriers in finally. A failed assertion should not leave a shared test process blocked.

Test the provider separately

Worker integration tests do not prove distributed claiming or retry transitions. Exercise provider behavior at its real database boundary, including:

• two concurrent claims do not return the same record;
• an expired claim becomes recoverable;
• completed and expired records are excluded;
• retry limits become terminal;
• cancellation is idempotent.