fix(drivers): wire PollGroupEngine onError->health + 30s poll backoff (05/STAB-9) [modbus,abcip,ablegacy]

2026-07-13 11:57:25 -04:00
parent ca6530c7f5
commit 9213c037b0
7 changed files with 239 additions and 4 deletions
@@ -0,0 +1,60 @@
+using System.Net.Sockets;
+using Shouldly;
+using Xunit;
+using ZB.MOM.WW.OtOpcUa.Core.Abstractions;
+
+namespace ZB.MOM.WW.OtOpcUa.Driver.Modbus.Tests;
+
+/// <summary>
+///     05/STAB-9 — the poll engine's <c>onError</c> sink must be wired to the driver health
+///     surface: a poll-loop reader failure degrades health while preserving
+///     <see cref="DriverHealth.LastSuccessfulRead"/>, and must never downgrade a pre-existing
+///     <see cref="DriverState.Faulted"/> (the S7 nuance ported fleet-wide).
+/// </summary>
+[Trait("Category", "Unit")]
+public sealed class ModbusPollErrorHealthTests
+{
+    private sealed class NoopTransport : IModbusTransport
+    {
+        public Task ConnectAsync(CancellationToken ct) => Task.CompletedTask;
+        public Task<byte[]> SendAsync(byte unitId, byte[] pdu, CancellationToken ct)
+            => Task.FromResult(new byte[] { 0x03, 0x00 });
+        public ValueTask DisposeAsync() => ValueTask.CompletedTask;
+    }
+
+    /// <summary>A poll reader failure degrades health, preserving the last successful read timestamp.</summary>
+    [Fact]
+    public async Task PollReaderFailure_DegradesHealth_PreservesLastSuccessfulRead()
+    {
+        var opts = new ModbusDriverOptions { Host = "fake", Probe = new ModbusProbeOptions { Enabled = false } };
+        var drv = new ModbusDriver(opts, "modbus-1", _ => new NoopTransport());
+        await drv.InitializeAsync("{}", CancellationToken.None);
+
+        var before = drv.GetHealth();
+        before.State.ShouldBe(DriverState.Healthy);
+        before.LastSuccessfulRead.ShouldNotBeNull();
+
+        drv.HandlePollError(new InvalidOperationException("poll boom"));
+
+        var after = drv.GetHealth();
+        after.State.ShouldBe(DriverState.Degraded);
+        after.LastSuccessfulRead.ShouldBe(before.LastSuccessfulRead);
+        after.LastError.ShouldContain("poll boom");
+    }
+
+    /// <summary>A poll reader failure never downgrades a pre-existing Faulted state.</summary>
+    [Fact]
+    public async Task PollReaderFailure_NeverDowngradesFaulted()
+    {
+        var opts = new ModbusDriverOptions { Host = "fake", Probe = new ModbusProbeOptions { Enabled = false } };
+        var drv = new ModbusDriver(opts, "modbus-1", _ => throw new SocketException());
+
+        // Init faults (the throwing factory) → Faulted, then rethrows.
+        await Should.ThrowAsync<Exception>(() => drv.InitializeAsync("{}", CancellationToken.None));
+        drv.GetHealth().State.ShouldBe(DriverState.Faulted);
+
+        drv.HandlePollError(new InvalidOperationException("poll boom"));
+
+        drv.GetHealth().State.ShouldBe(DriverState.Faulted);
+    }
+}