fix(commons): resolve Commons-013,014 — integral JSON index handling, distinguish Malformed vs Legacy OPC UA config

tests/ScadaLink.Commons.Tests/Types/DataConnections/OpcUaEndpointConfigSerializerTests.cs

@@ -168,6 +168,47 @@ public class OpcUaEndpointConfigSerializerTests
         Assert.True(result.IsLegacy);
     }
 
+    // ── Commons-014 regression: a corrupt typed row must not be mislabelled Legacy ──
+
+    [Fact]
+    public void Deserialize_TypedShapeWithInvalidEnum_ReportsMalformedNotLegacy()
+    {
+        // The row IS the current typed shape (it has endpointUrl) but an enum-valued
+        // field holds an unrecognised string. Typed deserialization throws JsonException;
+        // it must NOT fall through to the legacy path and be reported as Legacy.
+        var json = """{"endpointUrl":"opc.tcp://x:4840","securityMode":"NotARealMode"}""";
+
+        var result = OpcUaEndpointConfigSerializer.Deserialize(json);
+
+        Assert.Equal(OpcUaConfigParseStatus.Malformed, result.Status);
+        Assert.False(result.IsLegacy);
+    }
+
+    [Fact]
+    public void Deserialize_TypedShapeWithWrongTypeField_ReportsMalformedNotLegacy()
+    {
+        // endpointUrl present (typed shape) but a numeric field holds a non-numeric token.
+        var json = """{"endpointUrl":"opc.tcp://x:4840","sessionTimeoutMs":"not-a-number"}""";
+
+        var result = OpcUaEndpointConfigSerializer.Deserialize(json);
+
+        Assert.Equal(OpcUaConfigParseStatus.Malformed, result.Status);
+        Assert.False(result.IsLegacy);
+    }
+
+    [Fact]
+    public void Deserialize_ValidTypedRow_StillReportsTyped()
+    {
+        // Guard: a clean typed row is still classified Typed after the Commons-014 fix.
+        var json = """{"endpointUrl":"opc.tcp://x:4840","securityMode":"sign"}""";
+
+        var result = OpcUaEndpointConfigSerializer.Deserialize(json);
+
+        Assert.Equal(OpcUaConfigParseStatus.Typed, result.Status);
+        Assert.Equal("opc.tcp://x:4840", result.Config.EndpointUrl);
+        Assert.Equal(OpcUaSecurityMode.Sign, result.Config.SecurityMode);
+    }
+
     [Fact]
     public void Deserialize_TwoElementDeconstruction_StillWorks()
     {

tests/ScadaLink.Commons.Tests/Types/DynamicJsonElementTests.cs

@@ -144,4 +144,48 @@ public class DynamicJsonElementTests
         Assert.False(strWrapper.TryConvert(convBinder, out var result));
         Assert.Null(result);
     }
+
+    // ── Commons-013 regression: integral index values other than int must work ──
+
+    [Fact]
+    public void IndexAccess_WithLongIndex_Works()
+    {
+        // DynamicJsonElement.Wrap surfaces JSON numbers as long; an index computed
+        // from a wrapped JSON number (obj.items[obj.count - 1]) arrives as a long.
+        dynamic obj = Wrap("""{ "items": [ "a", "b", "c" ] }""");
+        long idx = 1L;
+
+        Assert.Equal("b", obj.items[idx]);
+    }
+
+    [Fact]
+    public void IndexAccess_WithIndexDerivedFromWrappedJsonNumber_Works()
+    {
+        // The exact failing case from Commons-013: count is a wrapped JSON number
+        // (unwrapped as long), so count - 1 is a long.
+        dynamic obj = Wrap("""{ "items": [ "a", "b", "c" ], "count": 3 }""");
+
+        Assert.Equal("c", obj.items[obj.count - 1]);
+    }
+
+    [Theory]
+    [InlineData((byte)0, "a")]
+    [InlineData((short)1, "b")]
+    public void IndexAccess_WithWideningIntegralIndex_Works(object index, string expected)
+    {
+        dynamic obj = Wrap("""{ "items": [ "a", "b", "c" ] }""");
+
+        Assert.Equal(expected, obj.items[index]);
+    }
+
+    [Fact]
+    public void IndexAccess_WithLongIndexOutOfRange_Throws()
+    {
+        // An out-of-range long index is still rejected (binder surfaces the error).
+        dynamic obj = Wrap("""{ "items": [ "a" ] }""");
+        long idx = 5L;
+
+        Assert.Throws<Microsoft.CSharp.RuntimeBinder.RuntimeBinderException>(
+            () => { var _ = obj.items[idx]; });
+    }
 }