review(Driver.Modbus.Cli): FlushLogging() + interval validation + banner-before-events

Re-review at 7286d320. -009 FlushLogging() in finally; -010 validate --interval-ms positive
(+8 tests); -011 print subscribe banner before wiring OnDataChange (no main/poll-thread
interleave). Parity with AbCip.Cli.

src/Drivers/Cli/ZB.MOM.WW.OtOpcUa.Driver.Modbus.Cli/Commands/ProbeCommand.cs

@@ -68,6 +68,9 @@ public sealed class ProbeCommand : ModbusCommandBase
         finally
         {
             await driver.ShutdownAsync(CancellationToken.None);
+            // Driver.Modbus.Cli-009: flush Serilog before process exit so buffered log lines
+            // emitted during driver shutdown are not lost. Matches Driver.AbCip.Cli pattern.
+            FlushLogging();
         }
     }
 

src/Drivers/Cli/ZB.MOM.WW.OtOpcUa.Driver.Modbus.Cli/Commands/ReadCommand.cs

@@ -86,6 +86,9 @@ public sealed class ReadCommand : ModbusCommandBase
         finally
         {
             await driver.ShutdownAsync(CancellationToken.None);
+            // Driver.Modbus.Cli-009: flush Serilog before process exit so buffered log lines
+            // emitted during driver shutdown are not lost. Matches Driver.AbCip.Cli pattern.
+            FlushLogging();
         }
     }
 

src/Drivers/Cli/ZB.MOM.WW.OtOpcUa.Driver.Modbus.Cli/Commands/SubscribeCommand.cs

@@ -63,6 +63,9 @@ public sealed class SubscribeCommand : ModbusCommandBase
     {
         ConfigureLogging();
         ValidateEndpoint();
+        // Driver.Modbus.Cli-010: reject non-positive interval before opening the driver so
+        // the operator gets a clean error instead of a confusing PollGroupEngine failure.
+        ValidateInterval(IntervalMs);
         var ct = console.RegisterCancellationHandler();
 
         var tagName = ReadCommand.SynthesiseTagName(Region, Address, DataType);
@@ -87,6 +90,14 @@ public sealed class SubscribeCommand : ModbusCommandBase
         {
             await driver.InitializeAsync("{}", ct);
 
+            // Driver.Modbus.Cli-011: emit the banner BEFORE wiring OnDataChange so the
+            // main-thread WriteLineAsync cannot interleave with poll-thread change-event
+            // writes. TextWriter.WriteLine is not guaranteed thread-safe; once the handler
+            // is attached and SubscribeAsync starts, change events run on the poll thread.
+            // Mirrors the ordering in Driver.AbCip.Cli.SubscribeCommand.
+            await console.Output.WriteLineAsync(
+                $"Subscribed to {tagName} @ {IntervalMs}ms. Ctrl+C to stop.");
+
             // Route every data-change event to the CliFx console (not System.Console — the
             // analyzer flags it + IConsole is the testable abstraction).
             driver.OnDataChange += (_, e) =>
@@ -114,9 +125,6 @@ public sealed class SubscribeCommand : ModbusCommandBase
             };
 
             handle = await driver.SubscribeAsync([tagName], TimeSpan.FromMilliseconds(IntervalMs), ct);
-
-            await console.Output.WriteLineAsync(
-                $"Subscribed to {tagName} @ {IntervalMs}ms. Ctrl+C to stop.");
             try
             {
                 await Task.Delay(System.Threading.Timeout.InfiniteTimeSpan, ct);
@@ -134,6 +142,26 @@ public sealed class SubscribeCommand : ModbusCommandBase
                 catch { /* teardown best-effort */ }
             }
             await driver.ShutdownAsync(CancellationToken.None);
+            // Driver.Modbus.Cli-009: flush Serilog before process exit so buffered log lines
+            // emitted just before Ctrl+C (e.g. during UnsubscribeAsync / ShutdownAsync) are
+            // not lost. Matches the pattern in Driver.AbCip.Cli commands.
+            FlushLogging();
         }
     }
+
+    /// <summary>
+    ///     Driver.Modbus.Cli-010: guards <c>--interval-ms</c> against zero or negative values.
+    ///     A non-positive interval would produce a non-positive <see cref="TimeSpan"/> into
+    ///     <c>SubscribeAsync</c>; the CLI should fail fast with an actionable error rather
+    ///     than relying on the downstream <c>PollGroupEngine</c> to clamp the value.
+    ///     Mirrors <c>Driver.AbCip.Cli.SubscribeCommand.ValidateInterval</c>.
+    /// </summary>
+    /// <param name="intervalMs">The polling interval in milliseconds.</param>
+    internal static void ValidateInterval(int intervalMs)
+    {
+        if (intervalMs <= 0)
+            throw new CliFx.Exceptions.CommandException(
+                $"--interval-ms must be > 0 (got {intervalMs}). " +
+                "PollGroupEngine floors sub-250ms values, but accepts any positive integer.");
+    }
 }

src/Drivers/Cli/ZB.MOM.WW.OtOpcUa.Driver.Modbus.Cli/Commands/WriteCommand.cs

@@ -112,6 +112,9 @@ public sealed class WriteCommand : ModbusCommandBase
         finally
         {
             await driver.ShutdownAsync(CancellationToken.None);
+            // Driver.Modbus.Cli-009: flush Serilog before process exit so buffered log lines
+            // emitted during driver shutdown are not lost. Matches Driver.AbCip.Cli pattern.
+            FlushLogging();
         }
     }