Phase 3 PR 65 -- S7 ITagDiscovery + ISubscribable polling overlay + IHostConnectivityProbe. Three more capability interfaces on S7Driver, matching the Modbus driver's capability coverage. ITagDiscovery: DiscoverAsync streams every configured tag into IAddressSpaceBuilder under a single 'S7' folder; builder.Variable gets a DriverAttributeInfo carrying DriverDataType (MapDataType: Bool->Boolean, Byte/Int/UInt sizes->Int32 (until Core.Abstractions adds widths), Float32/Float64 direct, String + DateTime direct), SecurityClass (Operate if tag.Writable else ViewOnly -- matches the Modbus pattern so DriverNodeManager's ACL layer can gate writes per role without S7-specific logic), IsHistorized=false (S7 has no native historian surface), IsAlarm=false (S7 alarms land through TIA Portal's alarm-in-DB pattern which is per-site and out of scope for PR 65). ISubscribable polling overlay: same pattern Modbus established in PR 22. SubscribeAsync spawns a Task.Run loop that polls every tag, diffs against LastValues, raises OnDataChange on changes plus a force-raise on initial-data push per OPC UA Part 4 convention. Interval floored at 100ms -- S7 CPUs scan 2-10ms but process the comms mailbox at most once per scan, so sub-scan polling just queues wire-side with worse latency per S7netplus documented pattern. Poll errors tolerated: first-read fault doesn't kill the loop (caller can't receive initial values but subsequent polls try again); transient poll errors also swallowed so the loop survives a power-cycle + reconnect through the health surface. UnsubscribeAsync cancels the CTS + removes the subscription -- unknown handle is a no-op, not a throw, because the caller's race with server-side cleanup shouldn't crash either side. Shutdown tears down every subscription before disposing the Plc. IHostConnectivityProbe: HostName surfaced as host:port to match Modbus driver convention (Admin /hosts dashboard renders both families uniformly). GetHostStatuses returns one row (single-endpoint driver). ProbeLoopAsync serializes on the shared Gate + calls Plc.ReadStatusAsync (cheap Get-CPU-Status PDU that doubles as an 'is PLC up' check) every Probe.Interval with a Probe.Timeout cap, transitions HostState Unknown/Stopped -> Running on success and -> Stopped on any failure, raises OnHostStatusChanged only on actual transitions (no noise for steady-state probes). Probe loop starts at end of InitializeAsync when Probe.Enabled=true (default); Shutdown cancels the probe CTS. Initial state stays Unknown until first successful probe -- avoids broadcasting a premature Running before any PDU round-trip has happened. Unit tests (S7DiscoveryAndSubscribeTests, 4 facts): DiscoverAsync_projects_every_tag_into_the_address_space (3 tags + mixed writable/read-only -> Operate vs ViewOnly asserted), GetHostStatuses_returns_one_row_with_host_port_identity_pre_init, SubscribeAsync_returns_unique_handles_and_UnsubscribeAsync_accepts_them (diagnosticId uniqueness + idempotent double-unsubscribe), Subscribe_publishing_interval_is_floored_at_100ms (accepts 50ms request without throwing -- floor is applied internally). Uses a RecordingAddressSpaceBuilder stub that implements IVariableHandle.FullReference + MarkAsAlarmCondition (throws NotImplementedException since the S7 driver never calls it -- alarms out of scope). 57/57 S7 unit tests pass. dotnet build clean. All 5 capability interfaces (IDriver/ITagDiscovery/IReadable/IWritable/ISubscribable/IHostConnectivityProbe) now implemented -- the S7 driver surface is on par with the Modbus driver, minus the extended data types (Int64/UInt64/Float64/String/DateTime deferred per PR 64).

2026-04-19 00:16:10 -04:00
parent 5e318a1ab6
commit d8ef35d5bd
2 changed files with 324 additions and 1 deletions
--- a/tests/ZB.MOM.WW.OtOpcUa.Driver.S7.Tests/S7DiscoveryAndSubscribeTests.cs
+++ b/tests/ZB.MOM.WW.OtOpcUa.Driver.S7.Tests/S7DiscoveryAndSubscribeTests.cs
@@ -0,0 +1,117 @@
+using Shouldly;
+using Xunit;
+using ZB.MOM.WW.OtOpcUa.Core.Abstractions;
+
+namespace ZB.MOM.WW.OtOpcUa.Driver.S7.Tests;
+
+/// <summary>
+///     Shape tests for <see cref="S7Driver"/>'s <see cref="ITagDiscovery"/>,
+///     <see cref="ISubscribable"/>, and <see cref="IHostConnectivityProbe"/> surfaces that
+///     don't need a live PLC. Wire-level polling round-trips and probe transitions land in a
+///     follow-up PR once we have a mock S7 server.
+/// </summary>
+[Trait("Category", "Unit")]
+public sealed class S7DiscoveryAndSubscribeTests
+{
+    private sealed class RecordingAddressSpaceBuilder : IAddressSpaceBuilder
+    {
+        public readonly List<string> Folders = new();
+        public readonly List<(string Name, DriverAttributeInfo Attr)> Variables = new();
+
+        public IAddressSpaceBuilder Folder(string browseName, string displayName)
+        {
+            Folders.Add(browseName);
+            return this;
+        }
+        public IVariableHandle Variable(string browseName, string displayName, DriverAttributeInfo attributeInfo)
+        {
+            Variables.Add((browseName, attributeInfo));
+            return new StubHandle();
+        }
+        public void AddProperty(string browseName, DriverDataType dataType, object? value) { }
+        public void AttachAlarmCondition(IVariableHandle sourceVariable, string alarmName, DriverAttributeInfo alarmInfo) { }
+
+        private sealed class StubHandle : IVariableHandle
+        {
+            public string FullReference => "stub";
+            public IAlarmConditionSink MarkAsAlarmCondition(AlarmConditionInfo info)
+                => throw new NotImplementedException("S7 driver never calls this — no alarm surfacing");
+        }
+    }
+
+    [Fact]
+    public async Task DiscoverAsync_projects_every_tag_into_the_address_space()
+    {
+        var opts = new S7DriverOptions
+        {
+            Host = "192.0.2.1",
+            Tags =
+            [
+                new("TempSetpoint", "DB1.DBW0", S7DataType.Int16, Writable: true),
+                new("FaultBit", "M0.0", S7DataType.Bool, Writable: false),
+                new("PIDOutput", "DB5.DBD12", S7DataType.Float32, Writable: true),
+            ],
+        };
+        using var drv = new S7Driver(opts, "s7-disco");
+
+        var builder = new RecordingAddressSpaceBuilder();
+        await drv.DiscoverAsync(builder, TestContext.Current.CancellationToken);
+
+        builder.Folders.ShouldContain("S7");
+        builder.Variables.Count.ShouldBe(3);
+        builder.Variables[0].Name.ShouldBe("TempSetpoint");
+        builder.Variables[0].Attr.SecurityClass.ShouldBe(SecurityClassification.Operate, "writable tags get Operate security class");
+        builder.Variables[1].Attr.SecurityClass.ShouldBe(SecurityClassification.ViewOnly, "read-only tags get ViewOnly");
+        builder.Variables[2].Attr.DriverDataType.ShouldBe(DriverDataType.Float32);
+    }
+
+    [Fact]
+    public void GetHostStatuses_returns_one_row_with_host_port_identity_pre_init()
+    {
+        var opts = new S7DriverOptions { Host = "plc1.internal", Port = 102 };
+        using var drv = new S7Driver(opts, "s7-host");
+
+        var rows = drv.GetHostStatuses();
+        rows.Count.ShouldBe(1);
+        rows[0].HostName.ShouldBe("plc1.internal:102");
+        rows[0].State.ShouldBe(HostState.Unknown, "pre-init / pre-probe state is Unknown");
+    }
+
+    [Fact]
+    public async Task SubscribeAsync_returns_unique_handles_and_UnsubscribeAsync_accepts_them()
+    {
+        var opts = new S7DriverOptions { Host = "192.0.2.1" };
+        using var drv = new S7Driver(opts, "s7-sub");
+
+        // SubscribeAsync does not itself call ReadAsync (the poll task does), so this works
+        // even though the driver isn't initialized. The poll task catches the resulting
+        // InvalidOperationException and the loop quietly continues — same pattern as the
+        // Modbus driver's poll loop tolerating transient transport failures.
+        var h1 = await drv.SubscribeAsync(["T1"], TimeSpan.FromMilliseconds(200), TestContext.Current.CancellationToken);
+        var h2 = await drv.SubscribeAsync(["T2"], TimeSpan.FromMilliseconds(200), TestContext.Current.CancellationToken);
+
+        h1.DiagnosticId.ShouldStartWith("s7-sub-");
+        h2.DiagnosticId.ShouldStartWith("s7-sub-");
+        h1.DiagnosticId.ShouldNotBe(h2.DiagnosticId);
+
+        await drv.UnsubscribeAsync(h1, TestContext.Current.CancellationToken);
+        await drv.UnsubscribeAsync(h2, TestContext.Current.CancellationToken);
+        // UnsubscribeAsync with an unknown handle must be a no-op, not throw.
+        await drv.UnsubscribeAsync(h1, TestContext.Current.CancellationToken);
+    }
+
+    [Fact]
+    public async Task Subscribe_publishing_interval_is_floored_at_100ms()
+    {
+        var opts = new S7DriverOptions { Host = "192.0.2.1", Probe = new S7ProbeOptions { Enabled = false } };
+        using var drv = new S7Driver(opts, "s7-floor");
+
+        // 50 ms requested — the floor protects the S7 CPU from sub-scan polling that would
+        // just queue wire-side. Test that the subscription is accepted (the floor is applied
+        // internally; the floor value isn't exposed, so we're really just asserting that the
+        // driver doesn't reject small intervals).
+        var h = await drv.SubscribeAsync(["T"], TimeSpan.FromMilliseconds(50), TestContext.Current.CancellationToken);
+        h.ShouldNotBeNull();
+        await drv.UnsubscribeAsync(h, TestContext.Current.CancellationToken);
+    }
+}