review(Driver.TwinCAT): thread ArrayLength through factory DTO (Medium)

Re-review at 7286d320. -017 (Medium): TwinCATTagDto lacked ArrayLength, so JSON-authored pre-declared array tags were silently scalar (Phase-4c array path dead for them). Fix: add ArrayLength to the DTO + thread through BuildTag with positive-value guard + TDD.
2026-06-19 11:47:11 -04:00
parent 91e2609560
commit 22f7d92b72
3 changed files with 130 additions and 3 deletions
@@ -186,6 +186,69 @@ public sealed class TwinCATArraySupportTests
        def!.ArrayLength.ShouldBeNull();
    }

+    // ---- (4) Driver.TwinCAT-017 — pre-declared array tag parseable via driver config JSON ----
+
+    /// <summary>
+    ///     A pre-declared tag in the driver config JSON with <c>arrayLength</c> must produce a
+    ///     <see cref="TwinCATTagDefinition"/> with the correct <see cref="TwinCATTagDefinition.ArrayLength"/>,
+    ///     which in turn drives <c>IsArray</c>/<c>ArrayDim</c> at discovery and a native array read
+    ///     at runtime (Driver.TwinCAT-017).
+    /// </summary>
+    [Fact]
+    public void Predeclared_array_tag_arrayLength_parses_from_driver_config_json()
+    {
+        var json = System.Text.Json.JsonSerializer.Serialize(new
+        {
+            devices = new[] { new { hostAddress = Host } },
+            tags = new[]
+            {
+                new
+                {
+                    name = "Speeds",
+                    deviceHostAddress = Host,
+                    symbolPath = "MAIN.Speeds",
+                    dataType = "DInt",
+                    arrayLength = 8,
+                },
+            },
+        });
+        var parsed = TwinCATDriverFactoryExtensions.ParseOptionsForTests(json, "drv-1");
+        parsed.Tags.Single().ArrayLength.ShouldBe(8);
+    }
+
+    /// <summary>
+    ///     A pre-declared array tag parsed from JSON must surface as <c>IsArray=true</c> /
+    ///     <c>ArrayDim=8</c> in the discovery address space.
+    /// </summary>
+    [Fact]
+    public async Task Predeclared_array_tag_from_json_reports_IsArray_in_discovery()
+    {
+        var configJson = System.Text.Json.JsonSerializer.Serialize(new
+        {
+            devices = new[] { new { hostAddress = Host } },
+            tags = new[]
+            {
+                new
+                {
+                    name = "Speeds",
+                    deviceHostAddress = Host,
+                    symbolPath = "MAIN.Speeds",
+                    dataType = "DInt",
+                    arrayLength = 8,
+                },
+            },
+        });
+        var builder = new RecordingBuilder();
+        var drv = new TwinCATDriver(new TwinCATDriverOptions(), "drv-1", new FakeTwinCATClientFactory());
+        await drv.InitializeAsync(configJson, CancellationToken.None);
+
+        await drv.DiscoverAsync(builder, CancellationToken.None);
+
+        var v = builder.Variables.Single(x => x.BrowseName == "Speeds").Info;
+        v.IsArray.ShouldBeTrue();
+        v.ArrayDim.ShouldBe(8u);
+    }
+
    // ---- helpers ----

    private sealed class RecordingBuilder : IAddressSpaceBuilder