test(focas): integration case for re-initialise under live wire reads (R07:H13)

Against the focas-mock fixture: the fixed-tree loop is running and reads are in flight while the driver re-initialises five times. No reader throws and reads keep returning Good. After shutdown, a fresh driver still connects and reads. Refs #740 Claude-Session: https://claude.ai/code/session_01Ub9hGmYLQvn9XETzw7CMsT
2026-10-22 14:27:38 -04:00
parent 2724d7dae8
commit 8ffa6178b5
1 changed files with 80 additions and 0 deletions
@@ -141,6 +141,86 @@ public sealed class WireBackendCoverageTests
        }
    }

+    /// <summary>
+    ///     #740 / R07:H13 — re-initialising a live driver (the fixed-tree loop running, reads in flight over the real
+    ///     wire) swaps the device table instead of clearing it under its readers: no reader throws, reads keep
+    ///     returning Good, and shutdown leaves no session behind (a fresh driver can still connect afterwards).
+    /// </summary>
+    [Fact]
+    public async Task Reinitialise_under_live_reads_swaps_the_device_table()
+    {
+        if (_fx.SkipReason is not null) Assert.Skip(_fx.SkipReason);
+        var ct = TestContext.Current.CancellationToken;
+
+        await _fx.LoadProfileAsync("FWLIB64", ct);
+        await _fx.PatchStateAsync(new
+        {
+            macros = new Dictionary<string, object> { ["500"] = new { value = 42000, @decimal = 3 } },
+        }, ct);
+
+        var drv = new FocasDriver(new FocasDriverOptions
+        {
+            Devices = [new FocasDeviceOptions(DeviceHost)],
+            RawTags = FocasRawTags.Entries(
+                new FocasTagDefinition("Macro500", DeviceHost, "MACRO:500", FocasDataType.Float64, Writable: false)),
+            Probe = new FocasProbeOptions { Enabled = false },
+            FixedTree = new FocasFixedTreeOptions
+            {
+                Enabled = true,
+                PollInterval = TimeSpan.FromMilliseconds(50),
+                ProgramPollInterval = TimeSpan.Zero,
+                TimerPollInterval = TimeSpan.Zero,
+            },
+        }, driverInstanceId: "wire-reinit-swap", clientFactory: new WireFocasClientFactory());
+
+        await using (drv)
+        {
+            await drv.InitializeAsync("{}", ct);
+            using var stop = CancellationTokenSource.CreateLinkedTokenSource(ct);
+            var errors = new ConcurrentQueue<Exception>();
+            var good = 0;
+            var reader = Task.Run(async () =>
+            {
+                while (!stop.IsCancellationRequested)
+                {
+                    try
+                    {
+                        _ = drv.GetHostStatuses();
+                        var s = await drv.ReadAsync(["Macro500", $"{DeviceHost}/Identity/SeriesNumber"], CancellationToken.None);
+                        if (s[0].StatusCode == FocasStatusMapper.Good) Interlocked.Increment(ref good);
+                    }
+                    catch (Exception ex) { errors.Enqueue(ex); }
+                }
+            }, CancellationToken.None);
+
+            for (var i = 0; i < 5; i++)
+            {
+                await Task.Delay(150, ct);
+                await drv.InitializeAsync("{}", ct);
+            }
+            await Task.Delay(300, ct);
+            stop.Cancel();
+            await reader;
+
+            errors.ShouldBeEmpty();
+            good.ShouldBeGreaterThan(0, "positive control: reads went over the wire between re-initialises");
+        }
+
+        // A fresh driver still connects and reads Good after the re-initialise churn and the shutdown.
+        var after = new FocasDriver(new FocasDriverOptions
+        {
+            Devices = [new FocasDeviceOptions(DeviceHost)],
+            RawTags = FocasRawTags.Entries(
+                new FocasTagDefinition("Macro500", DeviceHost, "MACRO:500", FocasDataType.Float64, Writable: false)),
+            Probe = new FocasProbeOptions { Enabled = false },
+        }, driverInstanceId: "wire-reinit-after", clientFactory: new WireFocasClientFactory());
+        await using (after)
+        {
+            await after.InitializeAsync("{}", ct);
+            (await after.ReadAsync(["Macro500"], ct))[0].StatusCode.ShouldBe(FocasStatusMapper.Good);
+        }
+    }
+
    /// <summary>Verifies that discover emits device folder and tag variables.</summary>
    [Fact]
    public async Task Discover_emits_device_folder_and_tag_variables()