feat(probe): OpcUaClient Test-Connect does a GetEndpoints discovery handshake

Replace the bare TCP-connect return in OpcUaClientDriverProbe with a real OPC UA GetEndpoints discovery handshake (mirroring SelectMatchingEndpointAsync in the driver). TCP preflight still fast-fails closed ports; the handshake confirms the remote is actually an OPC UA server, so a live-but-rejecting non-OPC-UA process now reads RED instead of a false-healthy green.
2026-06-16 06:39:27 -04:00
parent 9a8336ff6e
commit 957a63cfdb
2 changed files with 204 additions and 15 deletions
@@ -0,0 +1,137 @@
+using System.Net;
+using System.Net.Sockets;
+using Shouldly;
+using Xunit;
+
+namespace ZB.MOM.WW.OtOpcUa.Driver.OpcUaClient.Tests;
+
+/// <summary>
+///     Unit tests for <see cref="OpcUaClientDriverProbe"/>. Uses an in-process
+///     <see cref="TcpListener"/> on 127.0.0.1 to exercise the accept-then-close negative path
+///     (non-OPC-UA TCP server). The happy path (real OPC UA endpoints) is covered live.
+/// </summary>
+[Trait("Category", "Unit")]
+public sealed class OpcUaClientDriverProbeTests
+{
+    private readonly OpcUaClientDriverProbe _probe = new();
+
+    // ── 1. Invalid JSON ──────────────────────────────────────────────────────────
+
+    /// <summary>
+    ///     Invalid JSON returns Ok=false with a message containing "invalid".
+    /// </summary>
+    [Fact]
+    public async Task InvalidJson_returns_false_with_invalid_message()
+    {
+        var result = await _probe.ProbeAsync(
+            "not-json",
+            TimeSpan.FromSeconds(3),
+            TestContext.Current.CancellationToken);
+
+        result.Ok.ShouldBeFalse();
+        result.Message.ShouldNotBeNull();
+        result.Message!.ShouldContain("invalid", Case.Insensitive);
+    }
+
+    // ── 2. Config with no endpoint URL ───────────────────────────────────────────
+
+    /// <summary>
+    ///     Config JSON that resolves to no endpoint URL returns Ok=false with a message
+    ///     indicating no host/port was found.
+    /// </summary>
+    [Fact]
+    public async Task NoEndpointUrl_returns_false_with_no_host_port_message()
+    {
+        // Empty EndpointUrl + empty EndpointUrls → ExtractTarget returns ("", 0, "")
+        var result = await _probe.ProbeAsync(
+            """{"EndpointUrl":"","EndpointUrls":[]}""",
+            TimeSpan.FromSeconds(3),
+            TestContext.Current.CancellationToken);
+
+        result.Ok.ShouldBeFalse();
+        result.Message.ShouldNotBeNull();
+        result.Message!.ShouldContain("no host", Case.Insensitive);
+    }
+
+    // ── 3. Unreachable closed port ────────────────────────────────────────────────
+
+    /// <summary>
+    ///     Pointing at a TCP port that is not open returns Ok=false with a "Connect failed"
+    ///     message from the socket layer.
+    /// </summary>
+    [Fact]
+    public async Task ClosedPort_returns_false_with_connect_failed_message()
+    {
+        // Find a free port by letting the OS assign one, then immediately close the listener
+        // so nothing is bound at that port when we probe it.
+        var listener = new TcpListener(IPAddress.Loopback, 0);
+        listener.Start();
+        var port = ((IPEndPoint)listener.LocalEndpoint).Port;
+        listener.Stop();
+
+        var configJson = $$"""{"EndpointUrl":"opc.tcp://127.0.0.1:{{port}}"}""";
+
+        using var cts = new CancellationTokenSource(TimeSpan.FromSeconds(5));
+        var result = await _probe.ProbeAsync(configJson, TimeSpan.FromSeconds(5), cts.Token);
+
+        result.Ok.ShouldBeFalse();
+        result.Message.ShouldNotBeNull();
+        // SocketException on a closed port emits "Connect failed: ConnectionRefused" (or similar).
+        result.Message!.ShouldContain("Connect failed", Case.Insensitive);
+    }
+
+    // ── 4. TCP accept-then-close (non-OPC-UA server) ────────────────────────────
+
+    /// <summary>
+    ///     A TCP server that accepts but immediately closes the connection (simulating a
+    ///     non-OPC-UA process on the target port) causes the GetEndpoints handshake to fail.
+    ///     The result must be Ok=false and the message must contain "handshake failed".
+    /// </summary>
+    [Fact]
+    public async Task NonOpcUaTcpServer_returns_false_with_handshake_failed_message()
+    {
+        // Start a listener that accepts the connection and immediately closes it, simulating
+        // a non-OPC UA TCP service (e.g. an HTTP server or an SSH daemon) on the target port.
+        var listener = new TcpListener(IPAddress.Loopback, 0);
+        listener.Start();
+        var port = ((IPEndPoint)listener.LocalEndpoint).Port;
+
+        var testCt = TestContext.Current.CancellationToken;
+
+        // Accept in background — immediately close the socket so the OPC UA client gets EOF.
+        var acceptTask = Task.Run(async () =>
+        {
+            try
+            {
+                using var client = await listener.AcceptTcpClientAsync(testCt);
+                // Close immediately — the OPC UA handshake will get an EOF / broken pipe.
+            }
+            catch
+            {
+                // Listener may be stopped before a second accept; ignore.
+            }
+            finally
+            {
+                listener.Stop();
+            }
+        }, testCt);
+
+        try
+        {
+            var configJson = $$"""{"EndpointUrl":"opc.tcp://127.0.0.1:{{port}}"}""";
+
+            // Use a generous timeout so the test is not fragile on a slow CI box, but short
+            // enough to not block the suite for long if something goes wrong.
+            using var cts = new CancellationTokenSource(TimeSpan.FromSeconds(10));
+            var result = await _probe.ProbeAsync(configJson, TimeSpan.FromSeconds(10), cts.Token);
+
+            result.Ok.ShouldBeFalse();
+            result.Message.ShouldNotBeNull();
+            result.Message!.ShouldContain("handshake failed", Case.Insensitive);
+        }
+        finally
+        {
+            await acceptTask.WaitAsync(TimeSpan.FromSeconds(5), testCt);
+        }
+    }
+}