fix(abcip): explicit IsArray flag so 1-element arrays read as arrays (review I-1)

2026-06-16 22:14:41 -04:00
parent ce5d46be08
commit 94e8c55b5c
6 changed files with 172 additions and 42 deletions
@@ -181,22 +181,111 @@ public sealed class AbCipArrayTests
        factory.Tags["Recipe"].CreationParams.ElementCount.ShouldBe(4);
    }

-    /// <summary>The parser threads arrayLength into the transient definition's ElementCount.</summary>
+    /// <summary>The parser threads arrayLength into the transient definition's ElementCount and sets IsArray.</summary>
    [Fact]
    public void Parser_threads_arrayLength_into_ElementCount()
    {
        var json = """{"tagPath":"Recipe","dataType":"DInt","isArray":true,"arrayLength":8}""";
        AbCipEquipmentTagParser.TryParse(json, out var def).ShouldBeTrue();
        def!.ElementCount.ShouldBe(8);
+        def.IsArray.ShouldBeTrue();
    }

-    /// <summary>A non-array equipment ref defaults ElementCount to 1 (scalar).</summary>
+    /// <summary>A non-array equipment ref defaults ElementCount to 1 (scalar) and IsArray false.</summary>
    [Fact]
    public void Parser_defaults_ElementCount_to_one_when_not_an_array()
    {
        var json = """{"tagPath":"Recipe","dataType":"DInt"}""";
        AbCipEquipmentTagParser.TryParse(json, out var def).ShouldBeTrue();
        def!.ElementCount.ShouldBe(1);
+        def.IsArray.ShouldBeFalse();
+    }
+
+    /// <summary>
+    ///     Review finding I-1 — a 1-element array (<c>isArray:true, arrayLength:1</c>) is a valid
+    ///     1-element array, NOT a scalar: the parser sets <see cref="AbCipTagDefinition.IsArray"/>
+    ///     true and <see cref="AbCipTagDefinition.ElementCount"/> 1.
+    /// </summary>
+    [Fact]
+    public void Parser_treats_isArray_with_arrayLength_one_as_a_one_element_array()
+    {
+        var json = """{"tagPath":"Recipe","dataType":"DInt","isArray":true,"arrayLength":1}""";
+        AbCipEquipmentTagParser.TryParse(json, out var def).ShouldBeTrue();
+        def!.IsArray.ShouldBeTrue();
+        def.ElementCount.ShouldBe(1);
+    }
+
+    /// <summary>
+    ///     Review finding I-1 — <c>isArray:true, arrayLength:1</c> must DISCOVER as a [1] array node
+    ///     (IsArray + ArrayDim 1), matching the foundation's materialisation, not as a scalar.
+    /// </summary>
+    [Fact]
+    public async Task Equipment_ref_isArray_arrayLength_one_discovers_as_one_element_array()
+    {
+        var json = """{"deviceHostAddress":"ab://10.0.0.5/1,0","tagPath":"Recipe","dataType":"DInt","isArray":true,"arrayLength":1}""";
+        AbCipEquipmentTagParser.TryParse(json, out var def).ShouldBeTrue();
+
+        var builder = new RecordingBuilder();
+        var (drv, _) = NewDriver(def!);
+        await drv.InitializeAsync("{}", CancellationToken.None);
+
+        await drv.DiscoverAsync(builder, CancellationToken.None);
+
+        var arr = builder.Variables.Single().Info;
+        arr.IsArray.ShouldBeTrue();
+        arr.ArrayDim.ShouldBe(1u);
+    }
+
+    /// <summary>
+    ///     Review finding I-1 — the I-1 case: an <c>isArray:true, arrayLength:1</c> equipment tag
+    ///     reads a 1-ELEMENT typed array, NOT a scalar. On current code (gate <c>ElementCount &gt; 1</c>)
+    ///     this reads a scalar; the explicit IsArray flag fixes it.
+    /// </summary>
+    [Fact]
+    public async Task Equipment_ref_isArray_arrayLength_one_reads_as_one_element_array()
+    {
+        var json = """{"deviceHostAddress":"ab://10.0.0.5/1,0","tagPath":"Recipe","dataType":"DInt","isArray":true,"arrayLength":1}""";
+        var factory = new FakeAbCipTagFactory();
+        var opts = new AbCipDriverOptions
+        {
+            Devices = [new AbCipDeviceOptions("ab://10.0.0.5/1,0")],
+            Tags = [],
+        };
+        var drv = new AbCipDriver(opts, "abcip-eq-array1", factory);
+        await drv.InitializeAsync("{}", CancellationToken.None);
+        factory.Customise = p => new ArrayFakeAbCipTag(p, new int[] { 99 });
+
+        var snapshots = await drv.ReadAsync([json], CancellationToken.None);
+
+        snapshots.Single().StatusCode.ShouldBe(AbCipStatusMapper.Good);
+        var value = snapshots.Single().Value.ShouldBeOfType<int[]>();
+        value.ShouldBe([99]);
+        // A 1-element array still threads elem_count 1 to libplctag.
+        factory.Tags["Recipe"].CreationParams.ElementCount.ShouldBe(1);
+    }
+
+    /// <summary>
+    ///     Regression — a genuinely scalar equipment ref (<c>isArray:false</c>) reads a boxed
+    ///     scalar via <see cref="IAbCipTagRuntime.DecodeValue"/>, never an array.
+    /// </summary>
+    [Fact]
+    public async Task Equipment_ref_isArray_false_reads_as_scalar()
+    {
+        var json = """{"deviceHostAddress":"ab://10.0.0.5/1,0","tagPath":"Speed","dataType":"DInt","isArray":false}""";
+        var factory = new FakeAbCipTagFactory();
+        var opts = new AbCipDriverOptions
+        {
+            Devices = [new AbCipDeviceOptions("ab://10.0.0.5/1,0")],
+            Tags = [],
+        };
+        var drv = new AbCipDriver(opts, "abcip-eq-scalar", factory);
+        await drv.InitializeAsync("{}", CancellationToken.None);
+        factory.Customise = p => new FakeAbCipTag(p) { Value = 4200 };
+
+        var snapshots = await drv.ReadAsync([json], CancellationToken.None);
+
+        snapshots.Single().Value.ShouldBe(4200);
+        snapshots.Single().Value.ShouldNotBeOfType<int[]>();
    }

    // ---- helpers ----