Merge: fix systemic driver-config enum serialization (AdminUI authoring)

AdminUI driver-instance pages serialized enum config fields as JSON numbers,
but the driver factories' DTOs are string-typed + ParseEnum and throw on a
number — so AdminUI-authored configs with any enum field faulted the driver
on deploy. Add JsonStringEnumConverter to all 9 driver pages + 8 probes
(mirroring OpcUaClient). Found + fixed + live-verified by running the
never-before-run FB-9 (Modbus-Int64 authoring) and FB-10 (S7/AbCip probe)
verifies: an AdminUI-authored S7 driver now persists "cpuType":"S71500"
and connects to the sim; the probe E2E is 11/11 green.

src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.AbCip/AbCipDriverProbe.cs

@@ -39,6 +39,7 @@ public sealed class AbCipDriverProbe : IDriverProbe
     {
         PropertyNameCaseInsensitive = true,
         UnmappedMemberHandling = JsonUnmappedMemberHandling.Skip,
+        Converters = { new JsonStringEnumConverter() },
     };
 
     /// <inheritdoc />

src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.AbLegacy/AbLegacyDriverProbe.cs

@@ -39,6 +39,7 @@ public sealed class AbLegacyDriverProbe : IDriverProbe
     {
         PropertyNameCaseInsensitive = true,
         UnmappedMemberHandling = JsonUnmappedMemberHandling.Skip,
+        Converters = { new JsonStringEnumConverter() },
     };
 
     /// <inheritdoc />

src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.FOCAS/FocasDriverProbe.cs

@@ -44,6 +44,7 @@ public sealed class FocasDriverProbe : IDriverProbe
     {
         PropertyNameCaseInsensitive = true,
         UnmappedMemberHandling = JsonUnmappedMemberHandling.Skip,
+        Converters = { new JsonStringEnumConverter() },
     };
 
     /// <inheritdoc />

src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Galaxy/GalaxyDriverProbe.cs

@@ -35,6 +35,7 @@ public sealed class GalaxyDriverProbe : IDriverProbe
     {
         PropertyNameCaseInsensitive = true,
         UnmappedMemberHandling = JsonUnmappedMemberHandling.Skip,
+        Converters = { new JsonStringEnumConverter() },
     };
 
     /// <inheritdoc />

src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Historian.Wonderware.Client/WonderwareHistorianDriverProbe.cs

@@ -24,6 +24,7 @@ public sealed class WonderwareHistorianDriverProbe : IDriverProbe
     {
         PropertyNameCaseInsensitive = true,
         UnmappedMemberHandling = JsonUnmappedMemberHandling.Skip,
+        Converters = { new JsonStringEnumConverter() },
     };
 
     /// <inheritdoc />

src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Modbus/ModbusDriverProbe.cs

@@ -20,6 +20,7 @@ public sealed class ModbusDriverProbe : IDriverProbe
     {
         PropertyNameCaseInsensitive = true,
         UnmappedMemberHandling = JsonUnmappedMemberHandling.Skip,
+        Converters = { new JsonStringEnumConverter() },
     };
 
     // FC03 Read Holding Registers: function=0x03, addr-hi=0, addr-lo=0, qty-hi=0, qty-lo=1

src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.S7/S7DriverProbe.cs

@@ -24,6 +24,7 @@ public sealed class S7DriverProbe : IDriverProbe
     {
         PropertyNameCaseInsensitive = true,
         UnmappedMemberHandling = JsonUnmappedMemberHandling.Skip,
+        Converters = { new JsonStringEnumConverter() },
     };
 
     /// <inheritdoc />

src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.TwinCAT/TwinCATDriverProbe.cs

@@ -68,6 +68,7 @@ public sealed class TwinCATDriverProbe : IDriverProbe
     {
         PropertyNameCaseInsensitive = true,
         UnmappedMemberHandling = JsonUnmappedMemberHandling.Skip,
+        Converters = { new JsonStringEnumConverter() },
     };
 
     /// <summary>

src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Components/Pages/Clusters/Drivers/AbCipDriverPage.razor

@@ -224,6 +224,7 @@ else
         PropertyNamingPolicy = System.Text.Json.JsonNamingPolicy.CamelCase,
         UnmappedMemberHandling = System.Text.Json.Serialization.JsonUnmappedMemberHandling.Skip,
         WriteIndented = false,
+        Converters = { new System.Text.Json.Serialization.JsonStringEnumConverter() },
     };
 
     private FormModel _form = new();

src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Components/Pages/Clusters/Drivers/AbLegacyDriverPage.razor

@@ -190,6 +190,7 @@ else
         PropertyNamingPolicy = System.Text.Json.JsonNamingPolicy.CamelCase,
         UnmappedMemberHandling = System.Text.Json.Serialization.JsonUnmappedMemberHandling.Skip,
         WriteIndented = false,
+        Converters = { new System.Text.Json.Serialization.JsonStringEnumConverter() },
     };
 
     private FormModel _form = new();

src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Components/Pages/Clusters/Drivers/FocasDriverPage.razor

@@ -267,6 +267,7 @@ else
         PropertyNamingPolicy = System.Text.Json.JsonNamingPolicy.CamelCase,
         UnmappedMemberHandling = System.Text.Json.Serialization.JsonUnmappedMemberHandling.Skip,
         WriteIndented = false,
+        Converters = { new System.Text.Json.Serialization.JsonStringEnumConverter() },
     };
 
     private FormModel _form = new();

src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Components/Pages/Clusters/Drivers/GalaxyDriverPage.razor

@@ -218,6 +218,7 @@ else
         PropertyNameCaseInsensitive = true,
         UnmappedMemberHandling = System.Text.Json.Serialization.JsonUnmappedMemberHandling.Skip,
         WriteIndented = false,
+        Converters = { new System.Text.Json.Serialization.JsonStringEnumConverter() },
     };
 
     private FormModel _form = new();

src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Components/Pages/Clusters/Drivers/HistorianWonderwareDriverPage.razor

@@ -166,6 +166,7 @@ else
         PropertyNamingPolicy = System.Text.Json.JsonNamingPolicy.CamelCase,
         UnmappedMemberHandling = System.Text.Json.Serialization.JsonUnmappedMemberHandling.Skip,
         WriteIndented = false,
+        Converters = { new System.Text.Json.Serialization.JsonStringEnumConverter() },
     };
 
     private FormModel _form = new();

src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Components/Pages/Clusters/Drivers/ModbusDriverPage.razor

@@ -330,6 +330,7 @@ else
         PropertyNamingPolicy = System.Text.Json.JsonNamingPolicy.CamelCase,
         UnmappedMemberHandling = System.Text.Json.Serialization.JsonUnmappedMemberHandling.Skip,
         WriteIndented = false,
+        Converters = { new System.Text.Json.Serialization.JsonStringEnumConverter() },
     };
 
     private FormModel _form = new();

src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Components/Pages/Clusters/Drivers/OpcUaClientDriverPage.razor

@@ -279,6 +279,7 @@ else
         PropertyNamingPolicy = System.Text.Json.JsonNamingPolicy.CamelCase,
         UnmappedMemberHandling = System.Text.Json.Serialization.JsonUnmappedMemberHandling.Skip,
         WriteIndented = false,
+        Converters = { new System.Text.Json.Serialization.JsonStringEnumConverter() },
     };
 
     private FormModel _form = new();

src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Components/Pages/Clusters/Drivers/S7DriverPage.razor

@@ -196,6 +196,7 @@ else
         PropertyNamingPolicy = System.Text.Json.JsonNamingPolicy.CamelCase,
         UnmappedMemberHandling = System.Text.Json.Serialization.JsonUnmappedMemberHandling.Skip,
         WriteIndented = false,
+        Converters = { new System.Text.Json.Serialization.JsonStringEnumConverter() },
     };
 
     private FormModel _form = new();

src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Components/Pages/Clusters/Drivers/TwinCATDriverPage.razor

@@ -206,6 +206,7 @@ else
         PropertyNamingPolicy = System.Text.Json.JsonNamingPolicy.CamelCase,
         UnmappedMemberHandling = System.Text.Json.Serialization.JsonUnmappedMemberHandling.Skip,
         WriteIndented = false,
+        Converters = { new System.Text.Json.Serialization.JsonStringEnumConverter() },
     };
 
     private FormModel _form = new();

tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.Modbus.Tests/ModbusDriverConfigEnumSerializationTests.cs

@@ -0,0 +1,49 @@
+using System.Text.Json;
+using System.Text.Json.Serialization;
+using Shouldly;
+using Xunit;
+
+namespace ZB.MOM.WW.OtOpcUa.Driver.Modbus.Tests;
+
+/// <summary>
+///     Regression guard for the 2026-06-19 enum-serialization bug (the FB-9 Modbus-Int64 authoring
+///     case). The AdminUI Modbus page now serialises tag enums (<see cref="ModbusRegion"/>,
+///     <see cref="ModbusDataType"/>, byte-order) as STRINGS. This proves the factory parses that
+///     AdminUI-shaped Int64-tag blob, and documents that the pre-fix NUMERIC form threw because the
+///     <c>ModbusTagDto</c> enum fields are <c>string?</c>.
+/// </summary>
+public sealed class ModbusDriverConfigEnumSerializationTests
+{
+    // Mirrors the (now fixed) AdminUI ModbusDriverPage._jsonOpts: camelCase + string enums.
+    private static readonly JsonSerializerOptions _adminPageOpts = new()
+    {
+        PropertyNamingPolicy = JsonNamingPolicy.CamelCase,
+        Converters = { new JsonStringEnumConverter() },
+    };
+
+    /// <summary>Verifies the factory parses an AdminUI-authored Modbus config carrying an Int64
+    /// holding-register tag (string enums) without throwing.</summary>
+    [Fact]
+    public void Factory_parses_admin_authored_int64_string_enum_config()
+    {
+        var tag = new ModbusTagDefinition("Int64Tag", ModbusRegion.HoldingRegisters, (ushort)100, ModbusDataType.Int64);
+        var opts = new ModbusDriverOptions { Host = "10.0.0.5", Port = 502, UnitId = 1, Tags = new[] { tag } };
+        var blob = JsonSerializer.Serialize(opts, _adminPageOpts);
+        // The fixed AdminUI page must emit tag enums as strings, not numbers.
+        blob.ShouldContain("\"dataType\":\"Int64\"");
+
+        using var driver = ModbusDriverFactoryExtensions.CreateInstance("mb-test", blob);
+        driver.DriverType.ShouldBe("Modbus");
+    }
+
+    /// <summary>Documents the original bug: the pre-fix AdminUI page emitted numeric tag enums
+    /// (<c>"dataType":5,"region":3</c>) which the string-typed tag DTO cannot bind, so the factory throws.</summary>
+    [Fact]
+    public void Factory_throws_on_the_numeric_enum_form_the_pre_fix_page_emitted()
+    {
+        const string numericBlob =
+            "{\"host\":\"10.0.0.5\",\"port\":502,\"unitId\":1,\"tags\":[" +
+            "{\"name\":\"Int64Tag\",\"region\":3,\"address\":100,\"dataType\":5}]}";
+        Should.Throw<Exception>(() => ModbusDriverFactoryExtensions.CreateInstance("mb-test", numericBlob));
+    }
+}

tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.S7.Tests/S7DriverConfigEnumSerializationTests.cs

@@ -0,0 +1,48 @@
+using System.Text.Json;
+using System.Text.Json.Serialization;
+using Shouldly;
+using Xunit;
+
+namespace ZB.MOM.WW.OtOpcUa.Driver.S7.Tests;
+
+/// <summary>
+///     Regression guard for the 2026-06-19 enum-serialization bug. The AdminUI S7 page now
+///     serialises <see cref="S7CpuType"/> as a STRING (its <c>_jsonOpts</c> gained a
+///     <see cref="JsonStringEnumConverter"/>). This proves the factory parses that AdminUI-shaped
+///     blob and round-trips the enum, and documents that the pre-fix NUMERIC form — which the old
+///     page emitted — threw because <c>S7DriverConfigDto.CpuType</c> is <c>string?</c>.
+/// </summary>
+public sealed class S7DriverConfigEnumSerializationTests
+{
+    // Mirrors the (now fixed) AdminUI S7DriverPage._jsonOpts: camelCase + string enums.
+    private static readonly JsonSerializerOptions _adminPageOpts = new()
+    {
+        PropertyNamingPolicy = JsonNamingPolicy.CamelCase,
+        Converters = { new JsonStringEnumConverter() },
+    };
+
+    /// <summary>Verifies the factory parses an AdminUI-authored (string-enum) S7 config and
+    /// preserves the CpuType.</summary>
+    [Fact]
+    public void Factory_parses_admin_authored_string_enum_config()
+    {
+        var opts = new S7DriverOptions { Host = "10.0.0.5", Port = 102, CpuType = S7CpuType.S71500, Rack = 0, Slot = 1 };
+        var blob = JsonSerializer.Serialize(opts, _adminPageOpts);
+        // The fixed AdminUI page must emit the enum as a string, not a number.
+        blob.ShouldContain("\"cpuType\":\"S71500\"");
+
+        var parsed = S7DriverFactoryExtensions.ParseOptions("s7-test", blob);
+        parsed.CpuType.ShouldBe(S7CpuType.S71500);
+    }
+
+    /// <summary>Documents the original bug: the pre-fix AdminUI page emitted a numeric enum
+    /// (<c>"cpuType":40</c>) which the string-typed config DTO cannot bind, so the factory throws.</summary>
+    [Fact]
+    public void Factory_throws_on_the_numeric_enum_form_the_pre_fix_page_emitted()
+    {
+        // 40 == (int)S7CpuType.S71500 — exactly what the pre-fix page (no converter) wrote for S71500.
+        // The throw comes from binding a JSON number to the DTO's string? CpuType, so it fires for any number.
+        const string numericBlob = "{\"host\":\"10.0.0.5\",\"port\":102,\"cpuType\":40,\"rack\":0,\"slot\":1}";
+        Should.Throw<Exception>(() => S7DriverFactoryExtensions.ParseOptions("s7-test", numericBlob));
+    }
+}

tests/Server/ZB.MOM.WW.OtOpcUa.AdminUI.Tests/DriverPageJsonConverterTests.cs

@@ -0,0 +1,69 @@
+using System.Reflection;
+using System.Text.Json;
+using System.Text.Json.Serialization;
+using Shouldly;
+using Xunit;
+using ZB.MOM.WW.OtOpcUa.AdminUI.Components.Pages.Clusters.Drivers;
+
+namespace ZB.MOM.WW.OtOpcUa.AdminUI.Tests;
+
+/// <summary>
+///     Regression guard for the systemic driver-config enum-serialization bug found 2026-06-19.
+///     Every <c>*DriverPage</c> serialised enum config fields (e.g. S7 <c>CpuType</c>, Modbus
+///     <c>DataType</c>/<c>Region</c>, AbCip <c>PlcFamily</c>) as JSON <em>numbers</em> because its
+///     private static <c>_jsonOpts</c> had no <see cref="JsonStringEnumConverter"/>. The driver
+///     factories, however, deserialise into string-typed DTOs (+ lenient <c>ParseEnum</c>) and
+///     <em>throw</em> when binding a JSON number to a <c>string?</c> — so an AdminUI-authored
+///     config that contained any enum field produced a blob the driver could not parse, faulting
+///     the driver on deploy. The fix makes every page serialise enums as strings (matching the
+///     factory + the long-correct OpcUaClient template). This test fails if any driver page loses
+///     its string-enum converter again.
+/// </summary>
+public sealed class DriverPageJsonConverterTests
+{
+    /// <summary>Every concrete <c>*DriverPage</c> in the AdminUI assembly that declares a
+    /// <c>_jsonOpts</c> config serializer.</summary>
+    private static IReadOnlyList<Type> DriverPageTypes { get; } =
+        typeof(S7DriverPage).Assembly.GetTypes()
+            .Where(t => t.Name.EndsWith("DriverPage", StringComparison.Ordinal) && !t.IsAbstract)
+            .Where(t => t.GetField("_jsonOpts", BindingFlags.NonPublic | BindingFlags.Static) is not null)
+            .OrderBy(t => t.Name)
+            .ToList();
+
+    /// <summary>xUnit theory source over the driver-page types discovered by reflection.</summary>
+    public static TheoryData<Type> DriverPagesWithJsonOpts()
+    {
+        var data = new TheoryData<Type>();
+        foreach (var t in DriverPageTypes)
+            data.Add(t);
+        return data;
+    }
+
+    /// <summary>Verifies every driver page's config serializer registers a string-enum converter so
+    /// enum config fields round-trip as strings (and the driver factory can parse the result).</summary>
+    /// <param name="pageType">A driver page component type discovered by reflection.</param>
+    [Theory]
+    [MemberData(nameof(DriverPagesWithJsonOpts))]
+    public void Driver_page_json_options_register_string_enum_converter(Type pageType)
+    {
+        var field = pageType.GetField("_jsonOpts", BindingFlags.NonPublic | BindingFlags.Static);
+        var opts = (JsonSerializerOptions)field!.GetValue(null)!;
+        opts.Converters.OfType<JsonStringEnumConverter>().ShouldNotBeEmpty(
+            $"{pageType.Name}._jsonOpts must register a JsonStringEnumConverter; otherwise AdminUI-authored " +
+            "enum config fields serialise as numbers and the string-typed driver factory throws on parse.");
+    }
+
+    /// <summary>Enforces that EVERY concrete <c>*DriverPage</c> routes config serialization through a
+    /// <c>_jsonOpts</c> field — otherwise a new page that serialised config a different way would slip
+    /// past the converter guard above. Also a floor check so a rename can't silently shrink the set.</summary>
+    [Fact]
+    public void Every_driver_page_uses_a_guarded_jsonOpts_serializer()
+    {
+        var allDriverPages = typeof(S7DriverPage).Assembly.GetTypes()
+            .Where(t => t.Name.EndsWith("DriverPage", StringComparison.Ordinal) && !t.IsAbstract)
+            .ToList();
+        allDriverPages.Count.ShouldBeGreaterThanOrEqualTo(9, "reflection should discover the full driver-page fleet");
+        DriverPageTypes.Count.ShouldBe(allDriverPages.Count,
+            "every *DriverPage must declare a _jsonOpts config serializer so the string-enum converter guard covers it");
+    }
+}

tests/Server/ZB.MOM.WW.OtOpcUa.Host.IntegrationTests/DriverProbeHandshakeE2eTests.cs

@@ -172,8 +172,16 @@ public sealed class DriverProbeHandshakeE2eTests
     public async Task AbCip_Green_AgainstSim()
     {
         SkipUnless(DockerHost, AbCipPort);
+        // Probe an explicit tag that the ab_server ControlLogix sim actually defines
+        // (`TestDINT:DINT[1]`). The no-tags fallback (`@raw_cpu_type`) is NOT exercised here:
+        // ab_server answers an unknown/unsupported tag with libplctag ErrorBadParam (a REAL
+        // ControlLogix instead returns ErrorNotFound, which the probe classifies as
+        // reachable). Whether the `@raw_cpu_type` system-tag fallback is valid on a real
+        // ControlLogix is a hardware-gated follow-up (AbCipDriverOptions.cs flags it deferred).
         var result = await new AbCipDriverProbe().ProbeAsync(
-            $"{{\"Devices\":[{{\"HostAddress\":\"ab://{DockerHost}:{AbCipPort}/1,0\"}}]}}", Timeout, Ct);
+            $"{{\"Devices\":[{{\"HostAddress\":\"ab://{DockerHost}:{AbCipPort}/1,0\"}}]," +
+            $"\"Tags\":[{{\"DeviceHostAddress\":\"ab://{DockerHost}:{AbCipPort}/1,0\",\"TagPath\":\"TestDINT\"}}]}}",
+            Timeout, Ct);
         result.Ok.ShouldBeTrue($"Probe message: {result.Message}");
         result.Message!.ShouldContain("CIP session OK");
     }