feat(etl): add binary method overrides to DataTransformerBase

Add virtual methods to DataTransformerBase for GetBytes, GetChars, GetData, and GetDataTypeName that properly handle computed columns by throwing NotSupportedException when MapOrdinal returns -1. Update TransformingDataReader to delegate these methods to the transformer instead of directly to the source reader.
2026-01-03 10:33:13 -05:00
parent f5468d019f
commit 506ba5c61d
3 changed files with 213 additions and 5 deletions
@@ -225,8 +225,162 @@ public class TransformingDataReaderTests
        Assert.Equal("PassThrough", transformer.TransformerName);
    }

+    [Fact]
+    public void GetBytes_ComputedColumn_ThrowsNotSupportedException()
+    {
+        // Arrange - transformer that returns -1 for ordinal 0 (computed)
+        var source = Substitute.For<IDataReader>();
+        source.FieldCount.Returns(2);
+        source.GetName(0).Returns("Computed");
+        source.GetName(1).Returns("B");
+        var transformer = new ComputedColumnTransformer();
+        var reader = transformer.Transform(source);
+
+        // Act & Assert
+        Assert.Throws<NotSupportedException>(() =>
+            reader.GetBytes(0, 0, null, 0, 0));
+    }
+
+    [Fact]
+    public void GetChars_ComputedColumn_ThrowsNotSupportedException()
+    {
+        // Arrange - transformer that returns -1 for ordinal 0 (computed)
+        var source = Substitute.For<IDataReader>();
+        source.FieldCount.Returns(2);
+        source.GetName(0).Returns("Computed");
+        source.GetName(1).Returns("B");
+        var transformer = new ComputedColumnTransformer();
+        var reader = transformer.Transform(source);
+
+        // Act & Assert
+        Assert.Throws<NotSupportedException>(() =>
+            reader.GetChars(0, 0, null, 0, 0));
+    }
+
+    [Fact]
+    public void GetData_ComputedColumn_ThrowsNotSupportedException()
+    {
+        // Arrange - transformer that returns -1 for ordinal 0 (computed)
+        var source = Substitute.For<IDataReader>();
+        source.FieldCount.Returns(2);
+        source.GetName(0).Returns("Computed");
+        source.GetName(1).Returns("B");
+        var transformer = new ComputedColumnTransformer();
+        var reader = transformer.Transform(source);
+
+        // Act & Assert
+        Assert.Throws<NotSupportedException>(() =>
+            reader.GetData(0));
+    }
+
+    [Fact]
+    public void GetDataTypeName_ComputedColumn_ThrowsNotSupportedException()
+    {
+        // Arrange - transformer that returns -1 for ordinal 0 (computed)
+        var source = Substitute.For<IDataReader>();
+        source.FieldCount.Returns(2);
+        source.GetName(0).Returns("Computed");
+        source.GetName(1).Returns("B");
+        var transformer = new ComputedColumnTransformer();
+        var reader = transformer.Transform(source);
+
+        // Act & Assert
+        Assert.Throws<NotSupportedException>(() =>
+            reader.GetDataTypeName(0));
+    }
+
+    [Fact]
+    public void GetBytes_NonComputedColumn_DelegatesToSource()
+    {
+        // Arrange
+        var source = Substitute.For<IDataReader>();
+        source.FieldCount.Returns(2);
+        source.GetName(0).Returns("A");
+        source.GetName(1).Returns("B");
+        var expectedBytes = new byte[] { 1, 2, 3 };
+        source.GetBytes(1, 0, Arg.Any<byte[]?>(), 0, 3).Returns(3L);
+        var transformer = new PassThroughTransformer();
+        var reader = transformer.Transform(source);
+
+        // Act
+        var buffer = new byte[3];
+        var result = reader.GetBytes(1, 0, buffer, 0, 3);
+
+        // Assert
+        Assert.Equal(3L, result);
+        source.Received(1).GetBytes(1, 0, buffer, 0, 3);
+    }
+
+    [Fact]
+    public void GetChars_NonComputedColumn_DelegatesToSource()
+    {
+        // Arrange
+        var source = Substitute.For<IDataReader>();
+        source.FieldCount.Returns(2);
+        source.GetName(0).Returns("A");
+        source.GetName(1).Returns("B");
+        source.GetChars(1, 0, Arg.Any<char[]?>(), 0, 3).Returns(3L);
+        var transformer = new PassThroughTransformer();
+        var reader = transformer.Transform(source);
+
+        // Act
+        var buffer = new char[3];
+        var result = reader.GetChars(1, 0, buffer, 0, 3);
+
+        // Assert
+        Assert.Equal(3L, result);
+        source.Received(1).GetChars(1, 0, buffer, 0, 3);
+    }
+
+    [Fact]
+    public void GetData_NonComputedColumn_DelegatesToSource()
+    {
+        // Arrange
+        var source = Substitute.For<IDataReader>();
+        source.FieldCount.Returns(2);
+        source.GetName(0).Returns("A");
+        source.GetName(1).Returns("B");
+        var nestedReader = Substitute.For<IDataReader>();
+        source.GetData(1).Returns(nestedReader);
+        var transformer = new PassThroughTransformer();
+        var reader = transformer.Transform(source);
+
+        // Act
+        var result = reader.GetData(1);
+
+        // Assert
+        Assert.Same(nestedReader, result);
+        source.Received(1).GetData(1);
+    }
+
+    [Fact]
+    public void GetDataTypeName_NonComputedColumn_DelegatesToSource()
+    {
+        // Arrange
+        var source = Substitute.For<IDataReader>();
+        source.FieldCount.Returns(2);
+        source.GetName(0).Returns("A");
+        source.GetName(1).Returns("B");
+        source.GetDataTypeName(1).Returns("nvarchar");
+        var transformer = new PassThroughTransformer();
+        var reader = transformer.Transform(source);
+
+        // Act
+        var result = reader.GetDataTypeName(1);
+
+        // Assert
+        Assert.Equal("nvarchar", result);
+        source.Received(1).GetDataTypeName(1);
+    }
+
    private class PassThroughTransformer : DataTransformerBase
    {
        public override string TransformerName => "PassThrough";
    }
+
+    private class ComputedColumnTransformer : DataTransformerBase
+    {
+        public override string TransformerName => "Computed";
+        public override int MapOrdinal(int ordinal, IDataReader source) => ordinal == 0 ? -1 : ordinal;
+    }
 }