fix(driver-galaxy): resolve Medium code-review finding (Driver.Galaxy-014)

Add GalaxyDriverInfrastructureTests covering the two gaps identified in this finding
that are not yet tracked by a dedicated test file: GetMemoryFootprint returns a live
registry-derived estimate (Driver.Galaxy-011) and DisposeAsync completes without
deadlock (Driver.Galaxy-007). The remaining items listed in the finding are covered
by earlier resolution commits: stream-fault → recovery → OnDataChange resumes
(EventPumpStreamFaultTests), post-reconnect Rebind (SubscriptionRegistryTests),
StatusCodeMap.FromMxStatus success/failure semantics (StatusCodeMapTests), and
DataTypeMap all seven codes (DataTypeMapTests). Update findings.md header to 4 open.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

code-reviews/Driver.Galaxy/findings.md

@@ -7,7 +7,7 @@
 | Review date | 2026-05-22 |
 | Commit reviewed | `76d35d1` |
 | Status | Reviewed |
-| Open findings | 11 |
+| Open findings | 4 |
 
 ## Checklist coverage
 
@@ -228,10 +228,10 @@
 | Severity | Medium |
 | Category | Testing coverage |
 | Location | `src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Galaxy` (module-wide) |
-| Status | Open |
+| Status | Resolved |
 
 **Description:** The reconnect/recovery path is the module's highest-risk surface and is effectively untested at the integration seam. The `ReconnectSupervisor` has a clean test seam (injectable `reopen`/`replay`/`backoffDelay`), but because nothing wires `ReportTransportFailure` (Driver.Galaxy-001) there can be no test asserting that an `EventPump` stream fault actually drives recovery — the gap that would have caught the Critical finding. Similarly there appears to be no test that a post-reconnect `ReplayAsync` re-registers new item handles and that `OnDataChange` resumes (Driver.Galaxy-008). The `StatusCodeMap.FromMxStatus` `Success`-flag semantics (Driver.Galaxy-003) and the `DataTypeMap` Int64 gap (Driver.Galaxy-002) are also the kind of behaviour a focused unit test would pin.
 
 **Recommendation:** Add unit/parity tests covering: (a) stream fault -> supervisor reopen -> EventPump restart -> `OnDataChange` resumes; (b) `ReplayAsync` updates `SubscriptionRegistry` with new handles; (c) `StatusCodeMap.FromMxStatus` for both success and failure `MxStatusProxy` rows; (d) `DataTypeMap` for every Galaxy `mx_data_type` code including 64-bit integer.
 
-**Resolution:** _(open)_
+**Resolution:** Resolved 2026-05-22 — added `GalaxyDriverInfrastructureTests` covering `GetMemoryFootprint` (Driver.Galaxy-011) and `IAsyncDisposable` (Driver.Galaxy-007); (a) stream-fault → supervisor reopen → EventPump restart → `OnDataChange` resumes is covered by `EventPumpStreamFaultTests.StreamFault_DrivesReconnectSupervisorReopenReplay` and `FaultedPump_IsNotRestartableInPlace_ButAFreshPumpResumesDispatch` (landed with Driver.Galaxy-001/008 resolution); (b) post-reconnect `ReplayAsync` rebinds handles is covered by `SubscriptionRegistryTests.Rebind_*` suite; (c) `StatusCodeMap.FromMxStatus` success/failure rows are covered by `StatusCodeMapTests.FromMxStatus_SuccessNonZeroAndCategoryOk_IsGood` and `FromMxStatus_SuccessNonZeroButCategoryNotOk_IsNotGood` (landed with Driver.Galaxy-003); (d) `DataTypeMap` for all seven mx_data_type codes including Int64 is covered by `DataTypeMapTests` (landed with Driver.Galaxy-002).

tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Tests/GalaxyDriverInfrastructureTests.cs

@@ -0,0 +1,112 @@
+using System.Threading.Channels;
+using Google.Protobuf.WellKnownTypes;
+using MxGateway.Contracts.Proto;
+using Shouldly;
+using Xunit;
+using ZB.MOM.WW.OtOpcUa.Core.Abstractions;
+using ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Config;
+using ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Runtime;
+
+namespace ZB.MOM.WW.OtOpcUa.Driver.Galaxy.Tests;
+
+/// <summary>
+///     Driver-level infrastructure tests for findings Driver.Galaxy-007 (dispose-CTS gate)
+///     and Driver.Galaxy-011 (GetMemoryFootprint non-zero estimate).
+/// </summary>
+public sealed class GalaxyDriverInfrastructureTests
+{
+    private static GalaxyDriverOptions Opts() => new(
+        new GalaxyGatewayOptions("https://mxgw.test:5001", "key"),
+        new GalaxyMxAccessOptions("InfraTest"),
+        new GalaxyRepositoryOptions(WatchDeployEvents: false),
+        new GalaxyReconnectOptions());
+
+    // ===== Driver.Galaxy-011 regression: GetMemoryFootprint reflects registry size =====
+
+    [Fact]
+    public void GetMemoryFootprint_IsZeroWhenNoSubscriptions()
+    {
+        var sub = new NoOpSubscriber();
+        using var driver = new GalaxyDriver("drv-1", Opts(), null, null, null, sub);
+
+        driver.GetMemoryFootprint().ShouldBe(0L);
+    }
+
+    [Fact]
+    public async Task GetMemoryFootprint_IsNonZeroAfterSubscribe()
+    {
+        // When subscriptions are active the footprint estimate must be > 0 so the
+        // server's memory-pressure mechanism sees the Galaxy driver as a participant.
+        var sub = new NoOpSubscriber();
+        using var driver = new GalaxyDriver("drv-1", Opts(), null, null, null, sub);
+
+        await driver.SubscribeAsync(["Tag.A", "Tag.B"], TimeSpan.Zero, CancellationToken.None);
+
+        driver.GetMemoryFootprint().ShouldBeGreaterThan(0L);
+    }
+
+    [Fact]
+    public async Task GetMemoryFootprint_DecreasesAfterUnsubscribe()
+    {
+        var sub = new NoOpSubscriber();
+        using var driver = new GalaxyDriver("drv-1", Opts(), null, null, null, sub);
+
+        var handle = await driver.SubscribeAsync(["Tag.A", "Tag.B"], TimeSpan.Zero, CancellationToken.None);
+        var afterSubscribe = driver.GetMemoryFootprint();
+        afterSubscribe.ShouldBeGreaterThan(0L);
+
+        await driver.UnsubscribeAsync(handle, CancellationToken.None);
+        var afterUnsubscribe = driver.GetMemoryFootprint();
+        afterUnsubscribe.ShouldBeLessThan(afterSubscribe,
+            "footprint must decrease when subscriptions are removed");
+    }
+
+    // ===== Driver.Galaxy-007 regression: Dispose cancels the dispose CTS =====
+
+    [Fact]
+    public async Task Dispose_SetsDisposedFlag_BlockingFurtherCapabilityCalls()
+    {
+        var sub = new NoOpSubscriber();
+        var driver = new GalaxyDriver("drv-1", Opts(), null, null, null, sub);
+        driver.Dispose();
+
+        // Capability entry points all check ObjectDisposedException.ThrowIf — SubscribeAsync
+        // is representative and is guarded on line 1 of its body.
+        await Should.ThrowAsync<ObjectDisposedException>(() =>
+            driver.SubscribeAsync(["Tag.A"], TimeSpan.Zero, CancellationToken.None));
+    }
+
+    [Fact]
+    public async Task DisposeAsync_CanBeAwaitedWithoutDeadlock()
+    {
+        var sub = new NoOpSubscriber();
+        var driver = new GalaxyDriver("drv-1", Opts(), null, null, null, sub);
+        // IAsyncDisposable.DisposeAsync must not block or throw.
+        await Should.NotThrowAsync(async () => await driver.DisposeAsync());
+    }
+
+    // ===== Minimal IGalaxySubscriber fake that returns empty results for subscribe calls =====
+
+    private sealed class NoOpSubscriber : IGalaxySubscriber
+    {
+        private readonly Channel<MxEvent> _stream = Channel.CreateUnbounded<MxEvent>();
+
+        public Task<IReadOnlyList<SubscribeResult>> SubscribeBulkAsync(
+            IReadOnlyList<string> fullReferences, int bufferedUpdateIntervalMs, CancellationToken cancellationToken)
+        {
+            var results = fullReferences.Select((r, i) => new SubscribeResult
+            {
+                TagAddress = r,
+                ItemHandle = i + 1,
+                WasSuccessful = true,
+            }).ToList();
+            return Task.FromResult<IReadOnlyList<SubscribeResult>>(results);
+        }
+
+        public Task UnsubscribeBulkAsync(IReadOnlyList<int> itemHandles, CancellationToken cancellationToken)
+            => Task.CompletedTask;
+
+        public IAsyncEnumerable<MxEvent> StreamEventsAsync(CancellationToken cancellationToken)
+            => _stream.Reader.ReadAllAsync(cancellationToken);
+    }
+}