Joseph Doherty
2545237973
Closes the 5 "easily addable" W3 test gaps left after the prior W3 commit; the 5 race-hard gaps remain documented as known omissions per the plan. Tests: 382 pass / 0 fail (baseline 378 + 4 net new methods — the supervisor runtime-fault test replaces the existing placeholder). #11 BcdCodecTests.Encode16_IntMinValue_Throws_OutOfRange_NoArithmeticSurprise Locks the (uint)value > Max16 boundary check against int.MinValue. The cast becomes 0x80000000 which is well above 9999, so the throw fires cleanly. Prevents regression to a two-sided int comparison that would underflow. #15 BcdPduPipelineTests.FC03_Request_QtyAbove128_AtNonBcdAddress_PassesThroughUnchanged DL205/DL260 caps FC03/FC04 at qty=128 (DL260/dl205.md). The proxy must NOT truncate the qty field — passing through unchanged lets the PLC's own validator return exception 03 to the client (transparent contract for FCs/addresses the rewriter doesn't own). #4 SupervisorTests.Supervisor_RuntimeFault_OnRunningListener_RecoversAndRebinds Replaces the previous placeholder. Genuinely faults the running listener mid-life by stopping its underlying TcpListener via reflection (the single externally-observable hook to force the accept loop's AcceptAsync to throw ObjectDisposedException). Asserts the supervisor transitions to Recovering, re-binds via the Polly pipeline, and bumps RecoveryAttempts. #10 HotReloadE2ETests.E2E_ReadCoalescingEnabled_FlipAtRuntime_PropagatesToOptionsMonitor Validates that flipping Mbproxy.Resilience.ReadCoalescing.Enabled at runtime via hot-reload propagates through the live IOptionsMonitor. The W2.1 fix wires the accessor through to add/restart supervisors; the multiplexer reads it per-PDU (unit-tested separately). Proving IOptionsMonitor sees the new value is sufficient for the contract. #16 ConfigReconcilerTests.Apply_ManyConcurrentReloads_With_PlcChurn_NoCorruption Stress-tests the W2.3 ConcurrentDictionary fix. 16 concurrent applies cycle through 8 distinct PLC rosters, driving Add+Remove churn against the live supervisor dict. Without W2.3 the inner Task.WhenAll continuations would corrupt Dictionary<,> and crash with KeyNotFoundException / ArgumentException. Asserts every apply succeeds, no orphan supervisors remain, and the reload counter equals 16. The 5 deterministically-race-hard gaps (#5 TxId saturation propagation, #6 coalescing factory leak under saturation, #7 backend-reader head-of-line block, #8 watchdog↔response race, #9 cascade↔new-accept race) remain open by design — reproducing those races deterministically requires test seams in production code or stress-style tests that flake on slow CI. The Wave-1 fixes are still verified at the unit-contract level (UpstreamPipeTests.TrySendResponse_WhenChannelFull, etc.). This closes everything actionable in codereviews/2026-05-14/RemediationPlan.md. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>