Files
lmxopcua/tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.S7.Tests/S7DriverReconnectTests.cs
T
Joseph Doherty 1e26b9ab58 v3(s7): apply Modbus RawTags exemplar to the S7 driver
Rename S7EquipmentTagParser -> S7TagDefinitionFactory; TryParse(reference)
-> FromTagConfig(tagConfig, rawPath, out def) (drops the leading-{ heuristic,
keys the def by RawPath, adds inverse ToTagConfig). Replace S7DriverOptions.Tags
(pre-declared S7TagDefinition list) with RawTags (IReadOnlyList<RawTagEntry>);
the driver builds its RawPath->def table from RawTags at Initialize via the
factory (skip+log on miss), resolver is byName-only, DiscoverAsync + init guards
+ address pre-parse now run off that table. Factory retires the pre-declared DTO
tag path (RawTags binding only). Cli BuildOptions serialises typed defs to
RawTagEntry. Tests migrated to a S7RawTags helper + FromTagConfig; parser test
files renamed. Coordinator's EquipmentTagConfigInspector S7 rename left to Wave-B
coordinator; Driver.S7.IntegrationTests (Docker-gated) left red per scope.

Driver.S7 + Cli build green; Driver.S7.Tests 264/264, S7.Cli.Tests 49/49.
2026-07-15 20:11:04 -04:00

596 lines
28 KiB
C#

using S7.Net;
using Shouldly;
using Xunit;
using ZB.MOM.WW.OtOpcUa.Core.Abstractions;
using S7NetDataType = global::S7.Net.DataType;
namespace ZB.MOM.WW.OtOpcUa.Driver.S7.Tests;
/// <summary>
/// Unit tests for the S7 reconnect path (STAB-1). The <see cref="IS7PlcFactory"/> seam lets
/// these exercise the lazy <see cref="S7Driver"/> reconnect logic — dispose-dead-handle +
/// re-open on the next data call — without a live PLC, which was previously impossible (the
/// driver <c>new</c>-ed a concrete <c>S7.Net.Plc</c> inline and had no reopen path at all).
/// </summary>
[Trait("Category", "Unit")]
public sealed class S7DriverReconnectTests
{
private static S7DriverOptions Options() => new()
{
Host = "192.0.2.1",
Timeout = TimeSpan.FromMilliseconds(250),
// Probe off — these tests drive reconnect through the read path deterministically; a
// background probe would race the created-connection assertions.
Probe = new S7ProbeOptions { Enabled = false },
RawTags = S7RawTags.Entries(new S7TagDefinition("W0", "DB1.DBW0", S7DataType.UInt16, Writable: false)),
};
/// <summary>
/// A connection-fatal fault on a read marks the handle dead; the NEXT read disposes it and
/// opens a fresh connection, and the tag recovers to Good with health Degraded→Healthy.
/// </summary>
[Fact]
public async Task Read_reopens_a_fresh_connection_after_a_connection_fatal_fault()
{
var factory = new FakeS7PlcFactory();
using var drv = new S7Driver(Options(), "s7-reconnect", factory);
await drv.InitializeAsync("{}", TestContext.Current.CancellationToken);
factory.Created.Count.ShouldBe(1);
// Read #1 — good value, Healthy.
var r1 = await drv.ReadAsync(["W0"], TestContext.Current.CancellationToken);
r1[0].StatusCode.ShouldBe(0u);
drv.GetHealth().State.ShouldBe(DriverState.Healthy);
// The live socket drops on its next read. IsConnected deliberately stays true (a stale
// socket that hasn't noticed the drop) so the ONLY trigger for reopen is the driver's
// own dead-handle flag set by the connection-fatal classification.
factory.Created[0].NextReadThrows = new PlcException(ErrorCode.ConnectionError, "socket dropped");
// Read #2 — connection-fatal fault → Degraded, handle marked dead, but no reopen yet.
var r2 = await drv.ReadAsync(["W0"], TestContext.Current.CancellationToken);
r2[0].StatusCode.ShouldNotBe(0u);
drv.GetHealth().State.ShouldBe(DriverState.Degraded);
factory.Created.Count.ShouldBe(1);
// Read #3 — EnsureConnectedAsync disposes the dead handle and opens a SECOND connection,
// which reads Good; health recovers to Healthy.
var r3 = await drv.ReadAsync(["W0"], TestContext.Current.CancellationToken);
factory.Created.Count.ShouldBe(2);
r3[0].StatusCode.ShouldBe(0u);
drv.GetHealth().State.ShouldBe(DriverState.Healthy);
factory.Created[0].Disposed.ShouldBeTrue();
factory.Created[1].Disposed.ShouldBeFalse();
}
/// <summary>
/// R2-01 read-leg gate. A <see cref="TimeoutException"/> — what <c>S7OperationDeadline</c>
/// raises when a wire read blows its wall-clock ceiling on an established-but-frozen peer
/// (the async read S7.Net's ignored socket <c>ReadTimeout</c> can't bound) — is classified
/// connection-fatal: the handle is marked dead and the NEXT read reopens a fresh connection,
/// exactly like a socket drop. Before the fix a read-timeout was NOT fatal, so the wedged
/// handle was reused and the poll loop never recovered (<c>Created.Count</c> pinned at 1).
/// </summary>
[Fact]
public async Task Read_reopens_after_a_wire_operation_timeout()
{
var factory = new FakeS7PlcFactory();
using var drv = new S7Driver(Options(), "s7-read-timeout-fatal", factory);
await drv.InitializeAsync("{}", TestContext.Current.CancellationToken);
factory.Created.Count.ShouldBe(1);
// The next read blows its deadline — surfaces as a TimeoutException, the shape
// S7OperationDeadline raises for a frozen-but-established peer.
factory.Created[0].NextReadThrows = new TimeoutException("S7 read of 'DB1.DBW0' did not complete within 250 ms.");
// Read #1 — timeout → Degraded, handle marked dead, no reopen yet.
var bad = await drv.ReadAsync(["W0"], TestContext.Current.CancellationToken);
bad[0].StatusCode.ShouldNotBe(0u);
drv.GetHealth().State.ShouldBe(DriverState.Degraded);
factory.Created.Count.ShouldBe(1);
// Read #2 — disposes the dead handle, opens a SECOND connection, reads Good, recovers.
var recovered = await drv.ReadAsync(["W0"], TestContext.Current.CancellationToken);
recovered[0].StatusCode.ShouldBe(0u);
drv.GetHealth().State.ShouldBe(DriverState.Healthy);
factory.Created.Count.ShouldBe(2);
factory.Created[0].Disposed.ShouldBeTrue();
}
/// <summary>
/// A protocol / data-address error (S7.Net <see cref="ErrorCode.ReadData"/>) is NOT a
/// connection loss — the driver keeps the same connection and does not churn a reopen.
/// </summary>
[Fact]
public async Task Read_does_not_reopen_on_a_data_address_error()
{
var factory = new FakeS7PlcFactory();
using var drv = new S7Driver(Options(), "s7-dataerr", factory);
await drv.InitializeAsync("{}", TestContext.Current.CancellationToken);
// A data error — not a socket drop.
factory.Created[0].NextReadThrows = new PlcException(ErrorCode.ReadData, "bad address");
var bad = await drv.ReadAsync(["W0"], TestContext.Current.CancellationToken);
bad[0].StatusCode.ShouldNotBe(0u);
// Next read reuses the SAME connection — no reopen for a data error.
var ok = await drv.ReadAsync(["W0"], TestContext.Current.CancellationToken);
ok[0].StatusCode.ShouldBe(0u);
factory.Created.Count.ShouldBe(1);
}
/// <summary>
/// A raw socket exception (no S7.Net wrapper) is also classified connection-fatal and
/// triggers a reopen — the driver doesn't depend on every drop arriving as a
/// <see cref="PlcException"/>.
/// </summary>
[Fact]
public async Task Read_reopens_after_a_raw_socket_exception()
{
var factory = new FakeS7PlcFactory();
using var drv = new S7Driver(Options(), "s7-socket", factory);
await drv.InitializeAsync("{}", TestContext.Current.CancellationToken);
factory.Created[0].NextReadThrows = new System.Net.Sockets.SocketException();
await drv.ReadAsync(["W0"], TestContext.Current.CancellationToken);
drv.GetHealth().State.ShouldBe(DriverState.Degraded);
var recovered = await drv.ReadAsync(["W0"], TestContext.Current.CancellationToken);
recovered[0].StatusCode.ShouldBe(0u);
factory.Created.Count.ShouldBe(2);
}
/// <summary>
/// When the reopen itself fails (PLC still down), the batch degrades to a communication
/// error rather than throwing, and a later successful reopen recovers the tag.
/// </summary>
[Fact]
public async Task Read_degrades_when_reopen_fails_then_recovers()
{
var factory = new FakeS7PlcFactory();
using var drv = new S7Driver(Options(), "s7-reopen-fail", factory);
await drv.InitializeAsync("{}", TestContext.Current.CancellationToken);
// Drop the live socket, and make the NEXT-created connection fail to open.
factory.Created[0].NextReadThrows = new PlcException(ErrorCode.ConnectionError, "dropped");
factory.NextOpenThrows = new PlcException(ErrorCode.ConnectionError, "still down");
await drv.ReadAsync(["W0"], TestContext.Current.CancellationToken); // marks dead
// Reopen attempt #1 fails — whole batch is a comm error, no throw.
var down = await drv.ReadAsync(["W0"], TestContext.Current.CancellationToken);
down[0].StatusCode.ShouldNotBe(0u);
drv.GetHealth().State.ShouldBe(DriverState.Degraded);
// PLC comes back; the next call reopens cleanly and the tag reads Good.
var up = await drv.ReadAsync(["W0"], TestContext.Current.CancellationToken);
up[0].StatusCode.ShouldBe(0u);
drv.GetHealth().State.ShouldBe(DriverState.Healthy);
}
// ---- STAB-14: connect-timeout must degrade, not escape as OCE ----
/// <summary>
/// T1 (STAB-14 regression). When the reopen HANGS and is cut by the internal
/// <c>CancelAfter(_options.Timeout)</c> (the unreachable-host outage — SYNs dropped, not
/// refused), the read batch must degrade to a communication error with Degraded health,
/// NOT throw the timeout-born <see cref="TaskCanceledException"/> up to the caller.
/// Before the fix the OCE escaped <see cref="S7Driver.ReadAsync"/>.
/// </summary>
[Fact]
public async Task Read_degrades_batch_on_connect_timeout_instead_of_throwing()
{
var factory = new FakeS7PlcFactory();
using var drv = new S7Driver(Options(), "s7-read-timeout", factory);
await drv.InitializeAsync("{}", TestContext.Current.CancellationToken);
// Drop connection #1 so the next read reopens; every subsequent open hangs until the
// internal connect-timeout CTS fires.
factory.Created[0].NextReadThrows = new PlcException(ErrorCode.ConnectionError, "dropped");
await drv.ReadAsync(["W0"], TestContext.Current.CancellationToken); // marks dead
factory.OpenHangsUntilCancelledCount = int.MaxValue;
// Must NOT throw — the connect timeout degrades the batch.
var timedOut = await drv.ReadAsync(["W0"], TestContext.Current.CancellationToken);
timedOut[0].StatusCode.ShouldNotBe(0u);
drv.GetHealth().State.ShouldBe(DriverState.Degraded);
}
/// <summary>
/// T3 (STAB-14 regression). The same connect-timeout degrade through
/// <see cref="S7Driver.WriteAsync"/> — <c>EnsureConnectedAsync</c> is called before the
/// per-item loop, so a hanging reopen must degrade the whole write batch, not throw OCE.
/// </summary>
[Fact]
public async Task Write_degrades_batch_on_connect_timeout_instead_of_throwing()
{
var factory = new FakeS7PlcFactory();
using var drv = new S7Driver(Options(), "s7-write-timeout", factory);
await drv.InitializeAsync("{}", TestContext.Current.CancellationToken);
factory.Created[0].NextReadThrows = new PlcException(ErrorCode.ConnectionError, "dropped");
await drv.ReadAsync(["W0"], TestContext.Current.CancellationToken); // marks dead
factory.OpenHangsUntilCancelledCount = int.MaxValue;
var timedOut = await drv.WriteAsync(
[new WriteRequest("W0", (ushort)1)], TestContext.Current.CancellationToken);
timedOut[0].StatusCode.ShouldNotBe(0u);
drv.GetHealth().State.ShouldBe(DriverState.Degraded);
}
/// <summary>
/// T2 (STAB-14 regression). A subscription poll loop that ticks during an
/// unreachable-host outage (each reconnect times out) must SURVIVE and recover: a Good
/// <c>OnDataChange</c> must arrive after a Bad one once the host returns. Before the fix
/// the timeout-born OCE escaped <c>ReadAsync</c>, the poll loop's bare
/// <c>catch (OperationCanceledException) { return; }</c> read it as teardown, and the loop
/// died permanently — no recovery event ever fired (10 s deadline trips).
/// </summary>
[Fact]
public async Task Subscription_poll_loop_survives_a_connect_timeout_outage_and_recovers()
{
var factory = new FakeS7PlcFactory();
using var drv = new S7Driver(Options(), "s7-poll-survive", factory);
await drv.InitializeAsync("{}", TestContext.Current.CancellationToken);
var tcs = new TaskCompletionSource(TaskCreationOptions.RunContinuationsAsynchronously);
var sawBad = false;
drv.OnDataChange += (_, e) =>
{
if (e.Snapshot.StatusCode != 0u) sawBad = true;
else if (sawBad) tcs.TrySetResult();
};
// First poll tick drops the socket (marks dead); the next two reconnect attempts hang
// until the internal connect-timeout CTS fires; then opens succeed again.
factory.Created[0].NextReadThrows = new PlcException(ErrorCode.ConnectionError, "dropped");
factory.OpenHangsUntilCancelledCount = 2;
await drv.SubscribeAsync(["W0"], TimeSpan.FromMilliseconds(100), TestContext.Current.CancellationToken);
// Must observe a Good change AFTER a Bad one within the deadline — proves the loop lived.
await tcs.Task.WaitAsync(TimeSpan.FromSeconds(10), TestContext.Current.CancellationToken);
sawBad.ShouldBeTrue();
}
/// <summary>
/// T4 (pinning). Real CALLER cancellation during a connect must still propagate as
/// <see cref="OperationCanceledException"/> — the STAB-14 fix must not over-rotate into
/// swallowing genuine cancellation. Passes before and after the fix.
/// </summary>
[Fact]
public async Task Read_still_propagates_caller_cancellation_during_connect()
{
var opts = new S7DriverOptions
{
Host = "192.0.2.1",
Timeout = TimeSpan.FromSeconds(5), // long, so the CALLER token fires first, not the internal timeout
Probe = new S7ProbeOptions { Enabled = false },
RawTags = S7RawTags.Entries(new S7TagDefinition("W0", "DB1.DBW0", S7DataType.UInt16, Writable: false)),
};
var factory = new FakeS7PlcFactory();
using var drv = new S7Driver(opts, "s7-caller-cancel", factory);
await drv.InitializeAsync("{}", TestContext.Current.CancellationToken);
factory.Created[0].NextReadThrows = new PlcException(ErrorCode.ConnectionError, "dropped");
await drv.ReadAsync(["W0"], TestContext.Current.CancellationToken); // marks dead
factory.OpenHangsUntilCancelledCount = 1;
using var cts = new CancellationTokenSource();
cts.CancelAfter(50);
await Should.ThrowAsync<OperationCanceledException>(
async () => await drv.ReadAsync(["W0"], cts.Token));
}
// ---- STAB-15a: ISO-on-TCP framing/desync faults must reopen ----
/// <summary>
/// T5 (STAB-15a). A framing/desync fault on ISO-on-TCP (S7.Net's
/// <see cref="TPKTInvalidException"/> / <see cref="TPDUInvalidException"/> /
/// <see cref="WrongNumberOfBytesException"/>, or a <see cref="PlcException"/> carrying
/// <see cref="ErrorCode.WrongNumberReceivedBytes"/>) leaves the stream position
/// untrustworthy — only a reopen recovers. The next read must dispose connection #1 and
/// open a fresh #2. Before the fix these were not classified fatal, so the desynced handle
/// was reused forever (<c>Created.Count</c> pinned at 1).
/// </summary>
[Theory]
[InlineData("tpkt")]
[InlineData("tpdu")]
[InlineData("wrongbytes")]
[InlineData("plc-wrongnumber")]
public async Task Framing_faults_are_classified_connection_fatal_and_reopen(string kind)
{
Exception framing = kind switch
{
"tpkt" => new TPKTInvalidException(),
"tpdu" => new TPDUInvalidException(),
"wrongbytes" => new WrongNumberOfBytesException(),
"plc-wrongnumber" => new PlcException(ErrorCode.WrongNumberReceivedBytes, "short read"),
_ => throw new ArgumentOutOfRangeException(nameof(kind)),
};
var factory = new FakeS7PlcFactory();
using var drv = new S7Driver(Options(), "s7-framing", factory);
await drv.InitializeAsync("{}", TestContext.Current.CancellationToken);
// Read #1 hits the framing fault — Bad status, handle marked dead, but no reopen yet.
factory.Created[0].NextReadThrows = framing;
var bad = await drv.ReadAsync(["W0"], TestContext.Current.CancellationToken);
bad[0].StatusCode.ShouldNotBe(0u);
factory.Created.Count.ShouldBe(1);
// Read #2 reopens a fresh connection and reads Good.
var recovered = await drv.ReadAsync(["W0"], TestContext.Current.CancellationToken);
recovered[0].StatusCode.ShouldBe(0u);
factory.Created.Count.ShouldBe(2);
factory.Created[0].Disposed.ShouldBeTrue();
}
// ---- STAB-15a: cancellation observed mid-I/O must mark the handle dead ----
/// <summary>
/// T6 (STAB-15a). Cancellation observed WHILE a read is in flight abandons a half-read
/// ISO-on-TCP response on the single gated stream — the handle can't be reused. The OCE
/// must propagate (caller cancelled; nobody consumes the batch) AND mark the handle dead so
/// the next read reopens. Before the fix the read path converted the OCE to a Bad snapshot
/// and kept the desynced handle.
/// </summary>
[Fact]
public async Task Cancelled_read_marks_handle_dead_and_next_read_reopens()
{
var factory = new FakeS7PlcFactory();
using var drv = new S7Driver(Options(), "s7-cancel-read", factory);
await drv.InitializeAsync("{}", TestContext.Current.CancellationToken);
factory.Created[0].ReadHangsUntilCancelled = true;
using var cts = new CancellationTokenSource();
cts.CancelAfter(50);
await Should.ThrowAsync<OperationCanceledException>(
async () => await drv.ReadAsync(["W0"], cts.Token));
// Fresh-token read reopens a fresh connection.
var recovered = await drv.ReadAsync(["W0"], TestContext.Current.CancellationToken);
recovered[0].StatusCode.ShouldBe(0u);
factory.Created.Count.ShouldBe(2);
factory.Created[0].Disposed.ShouldBeTrue();
}
/// <summary>
/// T7 (STAB-15a). Cancellation observed while a WRITE is in flight likewise marks the
/// handle dead before propagating (the OCE already propagated pre-fix; the reopen is what
/// was missing).
/// </summary>
[Fact]
public async Task Cancelled_write_marks_handle_dead_and_next_read_reopens()
{
var opts = new S7DriverOptions
{
Host = "192.0.2.1",
Timeout = TimeSpan.FromMilliseconds(250),
Probe = new S7ProbeOptions { Enabled = false },
RawTags = S7RawTags.Entries(new S7TagDefinition("WW0", "DB1.DBW0", S7DataType.UInt16, Writable: true)),
};
var factory = new FakeS7PlcFactory();
using var drv = new S7Driver(opts, "s7-cancel-write", factory);
await drv.InitializeAsync("{}", TestContext.Current.CancellationToken);
factory.Created[0].WriteHangsUntilCancelled = true;
using var cts = new CancellationTokenSource();
cts.CancelAfter(50);
await Should.ThrowAsync<OperationCanceledException>(
async () => await drv.WriteAsync([new WriteRequest("WW0", (ushort)1)], cts.Token));
var recovered = await drv.ReadAsync(["WW0"], TestContext.Current.CancellationToken);
recovered[0].StatusCode.ShouldBe(0u);
factory.Created.Count.ShouldBe(2);
factory.Created[0].Disposed.ShouldBeTrue();
}
// ---- STAB-15b: the probe must mark a lying/hung handle dead so the next tick reopens ----
/// <summary>
/// T8 (STAB-15b). A probe failure on a handle whose <c>TcpClient.Connected</c> still lies
/// true (a wire-dead or desynced socket) must mark the handle dead under the gate, so the
/// NEXT probe tick's <c>EnsureConnectedAsync</c> disposes it and reopens. Before the fix the
/// probe swallowed the failure without marking dead, so the lying handle was re-probed
/// forever (<c>Created.Count</c> pinned at 1).
/// </summary>
[Fact]
public async Task Probe_failure_on_connected_socket_marks_dead_and_next_tick_reopens()
{
var opts = ProbeEnabledOptions();
var factory = new FakeS7PlcFactory();
using var drv = new S7Driver(opts, "s7-probe-fail", factory);
await drv.InitializeAsync("{}", TestContext.Current.CancellationToken);
// Arm connection #1 to fail EVERY probe with a connection-fatal fault (persistent). Later
// connections stay healthy (default ReadStatusThrows == null).
factory.Created[0].ReadStatusThrows = new System.Net.Sockets.SocketException();
await WaitUntilAsync(() => factory.Created.Count >= 2, TimeSpan.FromSeconds(5));
factory.Created.Count.ShouldBeGreaterThanOrEqualTo(2);
factory.Created[0].Disposed.ShouldBeTrue();
await WaitUntilAsync(() => drv.GetHostStatuses()[0].State == HostState.Running, TimeSpan.FromSeconds(5));
drv.GetHostStatuses()[0].State.ShouldBe(HostState.Running);
}
/// <summary>
/// T9 (STAB-15b). A probe that TIMES OUT mid-<c>ReadStatusAsync</c> (the CPU-status PDU may
/// still be in flight ⇒ desync) likewise marks the handle dead under the gate so the next
/// tick reopens. Before the fix the probe-deadline OCE fell to the bare swallow and the
/// handle was reused forever.
/// </summary>
[Fact]
public async Task Probe_timeout_marks_dead()
{
var opts = ProbeEnabledOptions();
var factory = new FakeS7PlcFactory();
using var drv = new S7Driver(opts, "s7-probe-timeout", factory);
await drv.InitializeAsync("{}", TestContext.Current.CancellationToken);
factory.Created[0].ReadStatusHangsUntilCancelled = true;
await WaitUntilAsync(() => factory.Created.Count >= 2, TimeSpan.FromSeconds(5));
factory.Created.Count.ShouldBeGreaterThanOrEqualTo(2);
factory.Created[0].Disposed.ShouldBeTrue();
await WaitUntilAsync(() => drv.GetHostStatuses()[0].State == HostState.Running, TimeSpan.FromSeconds(5));
drv.GetHostStatuses()[0].State.ShouldBe(HostState.Running);
}
private static S7DriverOptions ProbeEnabledOptions() => new()
{
Host = "192.0.2.1",
Timeout = TimeSpan.FromMilliseconds(250),
Probe = new S7ProbeOptions
{
Enabled = true,
Interval = TimeSpan.FromMilliseconds(50),
Timeout = TimeSpan.FromMilliseconds(250),
},
RawTags = S7RawTags.Entries(new S7TagDefinition("W0", "DB1.DBW0", S7DataType.UInt16, Writable: false)),
};
/// <summary>Polls <paramref name="condition"/> until it holds or <paramref name="timeout"/> elapses (returns either way).</summary>
private static async Task WaitUntilAsync(Func<bool> condition, TimeSpan timeout)
{
var deadline = DateTime.UtcNow + timeout;
while (DateTime.UtcNow < deadline)
{
if (condition()) return;
await Task.Delay(25).ConfigureAwait(false);
}
}
// ---- fakes ----
private sealed class FakeS7PlcFactory : IS7PlcFactory
{
/// <summary>Every connection handed out, in creation order.</summary>
public List<FakeS7Plc> Created { get; } = new();
/// <summary>When set, the NEXT <see cref="Create"/>d connection throws this on OpenAsync (once).</summary>
public Exception? NextOpenThrows { get; set; }
/// <summary>
/// Number of subsequently-created connections whose <see cref="FakeS7Plc.OpenAsync"/>
/// hangs until its token is cancelled (simulating the unreachable-but-not-refusing host
/// — pulled cable / firewall DROP — that STAB-14 needs and <c>docker restart</c> can't
/// produce). Each <see cref="Create"/> decrements it while positive.
/// </summary>
public int OpenHangsUntilCancelledCount { get; set; }
/// <summary>
/// When set, copied onto every created connection's persistent
/// <see cref="FakeS7Plc.ReadStatusThrows"/> so a probe fails on every tick. Clear it
/// after init to arm connection #1 only.
/// </summary>
public Exception? ReadStatusThrowsForNewConnections { get; set; }
public IS7Plc Create(S7CpuType cpuType, string host, int port, short rack, short slot, TimeSpan timeout)
{
var plc = new FakeS7Plc();
if (NextOpenThrows is { } ex)
{
plc.OpenThrowsOnce = ex;
NextOpenThrows = null;
}
if (OpenHangsUntilCancelledCount > 0)
{
plc.OpenHangsUntilCancelled = true;
OpenHangsUntilCancelledCount--;
}
if (ReadStatusThrowsForNewConnections is { } rex)
plc.ReadStatusThrows = rex;
Created.Add(plc);
return plc;
}
}
private sealed class FakeS7Plc : IS7Plc
{
public bool IsConnected { get; private set; }
public bool Disposed { get; private set; }
/// <summary>Thrown once by <see cref="OpenAsync"/>, then cleared.</summary>
public Exception? OpenThrowsOnce { get; set; }
/// <summary>
/// When true, <see cref="OpenAsync"/> hangs until its token is cancelled, then throws
/// <see cref="TaskCanceledException"/> — the connect-timeout shape (an unreachable host
/// whose SYNs are dropped) the live rig can't cheaply produce (STAB-14).
/// </summary>
public bool OpenHangsUntilCancelled { get; set; }
/// <summary>Thrown once by the next <see cref="ReadAsync"/>, then cleared.</summary>
public Exception? NextReadThrows { get; set; }
/// <summary>When true, <see cref="ReadAsync"/> hangs until its token is cancelled (STAB-15 cancel-mid-I/O).</summary>
public bool ReadHangsUntilCancelled { get; set; }
/// <summary>When true, <see cref="WriteAsync"/> hangs until its token is cancelled (STAB-15 cancel-mid-I/O).</summary>
public bool WriteHangsUntilCancelled { get; set; }
/// <summary>Thrown by EVERY <see cref="ReadStatusAsync"/> (persistent, not one-shot) — arms a probe fault (STAB-15b).</summary>
public Exception? ReadStatusThrows { get; set; }
/// <summary>When true, <see cref="ReadStatusAsync"/> hangs until its token is cancelled (probe-timeout, STAB-15b).</summary>
public bool ReadStatusHangsUntilCancelled { get; set; }
/// <summary>Boxed value returned by a good read (UInt16 tag → ushort).</summary>
public object? ReadValue { get; set; } = (ushort)42;
public async Task OpenAsync(CancellationToken cancellationToken)
{
if (OpenHangsUntilCancelled)
await Task.Delay(System.Threading.Timeout.Infinite, cancellationToken).ConfigureAwait(false);
if (OpenThrowsOnce is { } ex)
{
OpenThrowsOnce = null;
throw ex;
}
IsConnected = true;
}
public void Close() => IsConnected = false;
public async Task<object?> ReadAsync(string address, CancellationToken cancellationToken)
{
if (ReadHangsUntilCancelled)
await Task.Delay(System.Threading.Timeout.Infinite, cancellationToken).ConfigureAwait(false);
if (NextReadThrows is { } ex)
{
NextReadThrows = null;
throw ex;
}
return ReadValue;
}
public Task<byte[]> ReadBytesAsync(S7NetDataType area, int db, int startByteAdr, int count, CancellationToken cancellationToken) =>
throw new NotSupportedException("FakeS7Plc: block reads not needed for the reconnect tests");
public async Task WriteAsync(string address, object value, CancellationToken cancellationToken)
{
if (WriteHangsUntilCancelled)
await Task.Delay(System.Threading.Timeout.Infinite, cancellationToken).ConfigureAwait(false);
}
public Task WriteBytesAsync(S7NetDataType area, int db, int startByteAdr, byte[] value, CancellationToken cancellationToken) =>
Task.CompletedTask;
public async Task ReadStatusAsync(CancellationToken cancellationToken)
{
if (ReadStatusHangsUntilCancelled)
await Task.Delay(System.Threading.Timeout.Infinite, cancellationToken).ConfigureAwait(false);
if (ReadStatusThrows is { } ex)
throw ex;
}
public void Dispose()
{
Disposed = true;
IsConnected = false;
}
}
}