ScadaBridge/tests/ZB.MOM.WW.ScadaBridge.Communication.Tests/CoordinatorSupervisionTests.cs

using Akka.Actor;
using Akka.TestKit.Xunit2;
using Microsoft.Extensions.DependencyInjection;
using NSubstitute;
using ZB.MOM.WW.ScadaBridge.Commons.Interfaces.Repositories;
using ZB.MOM.WW.ScadaBridge.Communication.Actors;

namespace ZB.MOM.WW.ScadaBridge.Communication.Tests;

/// <summary>
/// Regression tests that coordinator actors must declare an
/// explicit <c>Resume</c> supervision strategy per the CLAUDE.md decision
/// ("Resume for coordinator actors"). A child fault under the default
/// (Restart) strategy would wipe a child's in-memory state; the long-lived
/// coordinators own per-site transport resources and must not silently discard
/// their children on a transient fault.
/// </summary>
public class CoordinatorSupervisionTests : TestKit
{
    /// <summary>
    /// Test-only subclass that exposes the protected <see cref="SupervisorStrategy"/>
    /// so the configured directive can be asserted directly.
    /// </summary>
    private sealed class CentralCommunicationActorProbe : CentralCommunicationActor
    {
        /// <summary>Initializes the probe with the dependencies required by the central communication actor.</summary>
        /// <param name="sp">The service provider passed to the base actor.</param>
        /// <param name="transport">The site command transport passed to the base actor.</param>
        public CentralCommunicationActorProbe(IServiceProvider sp, ISiteCommandTransport transport)
            : base(sp, transport) { }

        /// <summary>Returns the actor's configured supervisor strategy.</summary>
        /// <returns>The supervisor strategy declared by the actor.</returns>
        public SupervisorStrategy GetSupervisorStrategy() => SupervisorStrategy();
    }

    /// <summary>
    /// Test-only subclass that exposes the protected <see cref="SupervisorStrategy"/>.
    /// </summary>
    private sealed class SiteCommunicationActorProbe : SiteCommunicationActor
    {
        /// <summary>Initializes the probe with the dependencies required by the site communication actor.</summary>
        /// <param name="siteId">The site identifier passed to the base actor.</param>
        /// <param name="options">The communication options passed to the base actor.</param>
        /// <param name="dm">The deployment manager reference passed to the base actor.</param>
        public SiteCommunicationActorProbe(string siteId, CommunicationOptions options, IActorRef dm)
            : base(siteId, options, dm) { }

        /// <summary>Returns the actor's configured supervisor strategy.</summary>
        /// <returns>The supervisor strategy declared by the actor.</returns>
        public SupervisorStrategy GetSupervisorStrategy() => SupervisorStrategy();
    }

    private static IServiceProvider EmptyServiceProvider()
    {
        var mockRepo = Substitute.For<ISiteRepository>();
        mockRepo.GetAllSitesAsync(Arg.Any<CancellationToken>())
            .Returns(new List<Commons.Entities.Sites.Site>());
        var services = new ServiceCollection();
        services.AddScoped(_ => mockRepo);
        return services.BuildServiceProvider();
    }

    /// <summary>Verifies that the central communication actor declares a Resume supervisor strategy.</summary>
    [Fact]
    public void CentralCommunicationActor_SupervisorStrategy_IsResume()
    {
        var sp = EmptyServiceProvider();
        var transport = Substitute.For<ISiteCommandTransport>();

        var actorRef = new Akka.TestKit.TestActorRef<CentralCommunicationActorProbe>(
            Sys, Props.Create(() => new CentralCommunicationActorProbe(sp, transport)));

        var strategy = actorRef.UnderlyingActor.GetSupervisorStrategy();

        var oneForOne = Assert.IsType<OneForOneStrategy>(strategy);
        var directive = oneForOne.Decider.Decide(new InvalidOperationException("transient child fault"));
        Assert.Equal(Directive.Resume, directive);
    }

    /// <summary>Verifies that the site communication actor declares a Resume supervisor strategy.</summary>
    [Fact]
    public void SiteCommunicationActor_SupervisorStrategy_IsResume()
    {
        var dmProbe = CreateTestProbe();

        var actorRef = new Akka.TestKit.TestActorRef<SiteCommunicationActorProbe>(
            Sys, Props.Create(() => new SiteCommunicationActorProbe("site1", new CommunicationOptions(), dmProbe.Ref)));

        var strategy = actorRef.UnderlyingActor.GetSupervisorStrategy();

        var oneForOne = Assert.IsType<OneForOneStrategy>(strategy);
        var directive = oneForOne.Decider.Decide(new InvalidOperationException("transient child fault"));
        Assert.Equal(Directive.Resume, directive);
    }
}