Add transposition tests

QRCoderTests/QRCoderTests.csproj

@@ -14,6 +14,7 @@
     <PackageReference Include="KGySoft.Drawing" Version="9.2.0" />
     <PackageReference Include="KGySoft.Drawing.Core" Version="9.1.1" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.3.3" />
+    <PackageReference Include="Svg" Version="3.4.7" />
     <PackageReference Include="xunit" Version="2.9.2" />
     <PackageReference Include="xunit.runner.visualstudio" Version="2.4.3" />
     <PackageReference Include="shouldly" Version="4.3.0" />
@@ -59,11 +60,11 @@
   </ItemGroup>
 
   <ItemGroup>
-    <Using Include="QRCoder"/>
-    <Using Include="QRCoderTests.Helpers"/>
-    <Using Include="Shouldly"/>
-    <Using Include="System.Drawing"/>
-    <Using Include="Xunit"/>
+    <Using Include="QRCoder" />
+    <Using Include="QRCoderTests.Helpers" />
+    <Using Include="Shouldly" />
+    <Using Include="System.Drawing" />
+    <Using Include="Xunit" />
   </ItemGroup>
 
 </Project>

QRCoderTests/TransposeVerificationTests.ascii_renderer.FullSize.approved.txt

@@ -0,0 +1,29 @@
+
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+
+        ██████████████    ██  ████  ██████████████        
+        ██          ██  ████  ██    ██          ██        
+        ██  ██████  ██  ████    ██  ██  ██████  ██        
+        ██  ██████  ██    ██  ██    ██  ██████  ██        
+        ██  ██████  ██  ██      ██  ██  ██████  ██        
+        ██          ██  ██    ████  ██          ██        
+        ██████████████  ██  ██  ██  ██████████████        
+                        ██████████                        
+        ████  ██    ████  ████      ██████  ████          
+        ██  ████████    ████        ██                    
+        ██    ██    ██  ██████  ████        ██            
+          ██  ██████    ████  ██          ██  ████        
+        ██████  ██  ██████████  ██  ██  ████████          
+                        ████  ██      ██████  ██          
+        ██████████████  ████      ██  ██  ██              
+        ██          ██    ██████████  ██████  ████        
+        ██  ██████  ██    ██  ██    ██████  ██████        
+        ██  ██████  ██  ████  ██          ████████        
+        ██  ██████  ██    ██    ██      ██      ██        
+        ██          ██  ████      ████  ██  ██  ██        
+        ██████████████  ██  ██████      ██████            
+
+
+
+

QRCoderTests/TransposeVerificationTests.ascii_renderer.Small.approved.txt

@@ -0,0 +1,15 @@
+
+
+    █▀▀▀▀▀█ ▄█ █▀ █▀▀▀▀▀█    
+    █ ███ █ ▀█ ▄▀ █ ███ █    
+    █ ▀▀▀ █ █  ▄█ █ ▀▀▀ █    
+    ▀▀▀▀▀▀▀ █▄█▄█ ▀▀▀▀▀▀▀    
+    █▀▄█▄▄▀▀▄█▀   █▀▀ ▀▀     
+    ▀▄ █▄▄▀ ██▀▄▀▀   ▄▀▄▄    
+    ▀▀▀ ▀ ▀▀██▀▄▀ ▀▄██▀█     
+    █▀▀▀▀▀█ ▀█▄▄▄█ █▄█ ▄▄    
+    █ ███ █ ▄█ █  ▀▀▀▄███    
+    █ ▀▀▀ █ ▄█  ▀▄▄ █ ▄ █    
+    ▀▀▀▀▀▀▀ ▀ ▀▀▀   ▀▀▀      
+
+

QRCoderTests/TransposeVerificationTests.cs

@@ -0,0 +1,171 @@
+using System.IO;
+
+namespace QRCoderTests;
+
+/// <summary>
+/// Tests to verify that QR codes are not transposed along the main diagonal.
+/// All tests use the same QR code data with default renderer settings.
+/// Human verification of approval files is required to ensure correct orientation.
+/// </summary>
+public class TransposeVerificationTests
+{
+    private readonly QRCodeData _sharedQrCodeData;
+
+    public TransposeVerificationTests()
+    {
+        // Create a single QR code sample that will be used across all tests
+        // Using a distinctive pattern that makes transpose errors obvious
+        var gen = new QRCodeGenerator();
+        _sharedQrCodeData = gen.CreateQrCode("ABCD", QRCodeGenerator.ECCLevel.L);
+    }
+
+#if SYSTEM_DRAWING
+    [Theory]
+    [InlineData("QRCode")]
+    [InlineData("BitmapByteQRCode")]
+    [InlineData("Base64QRCode")]
+    [InlineData("PngByteQRCode")]
+    [InlineData("SvgQRCode")]
+    public void image_renderers(string rendererType)
+    {
+        byte[] imageBytes = rendererType switch
+        {
+            "QRCode" => GetQRCodeBytes(),
+            "BitmapByteQRCode" => GetBitmapByteQRCodeBytes(),
+            "Base64QRCode" => GetBase64QRCodeBytes(),
+            "PngByteQRCode" => GetPngByteQRCodeBytes(),
+            "SvgQRCode" => GetSvgQRCodeBytes(),
+            _ => throw new ArgumentException($"Unknown renderer type: {rendererType}")
+        };
+
+        imageBytes.ShouldMatchApprovedImage(asMonochrome: true);
+    }
+
+    private byte[] GetQRCodeBytes()
+    {
+        var qrCode = new QRCode(_sharedQrCodeData);
+        using var bitmap = qrCode.GetGraphic(10);
+        using var ms = new MemoryStream();
+        bitmap.Save(ms, System.Drawing.Imaging.ImageFormat.Png);
+        return ms.ToArray();
+    }
+
+    private byte[] GetBitmapByteQRCodeBytes()
+    {
+        var qrCode = new BitmapByteQRCode(_sharedQrCodeData);
+        return qrCode.GetGraphic(10);
+    }
+
+    private byte[] GetBase64QRCodeBytes()
+    {
+        var qrCode = new Base64QRCode(_sharedQrCodeData);
+        var base64String = qrCode.GetGraphic(10);
+        return Convert.FromBase64String(base64String);
+    }
+
+    private byte[] GetPngByteQRCodeBytes()
+    {
+        var qrCode = new PngByteQRCode(_sharedQrCodeData);
+        return qrCode.GetGraphic(10);
+    }
+
+    private byte[] GetSvgQRCodeBytes()
+    {
+        var qrCode = new SvgQRCode(_sharedQrCodeData);
+        var svgString = qrCode.GetGraphic(10);
+        var bitmapSize = _sharedQrCodeData.ModuleMatrix.Count * 10;
+        // use Svg.Net to render SVG to bitmap for comparison
+        var svgDoc = Svg.SvgDocument.FromSvg<Svg.SvgDocument>(svgString);
+        using var bitmap = svgDoc.Draw(bitmapSize, bitmapSize);
+        using var ms = new MemoryStream();
+        bitmap.Save(ms, System.Drawing.Imaging.ImageFormat.Png);
+        return ms.ToArray();
+    }
+
+    [Fact]
+    public void artqrcode_renderer()
+    {
+        var qrCode = new ArtQRCode(_sharedQrCodeData);
+        using var bitmap = qrCode.GetGraphic(10, Color.Black, Color.White, Color.White, null, 1, true, ArtQRCode.QuietZoneStyle.Flat, ArtQRCode.BackgroundImageStyle.Fill, null);
+        bitmap.ShouldMatchApproved();
+    }
+#endif
+
+    [Theory]
+    [InlineData("FullSize")]
+    [InlineData("Small")]
+    public void ascii_renderer(string sizeType)
+    {
+        var qrCode = new AsciiQRCode(_sharedQrCodeData);
+        var asciiArt = sizeType switch
+        {
+            "FullSize" => qrCode.GetGraphic(1),
+            "Small" => qrCode.GetGraphicSmall(invert: true),
+            _ => throw new ArgumentException($"Unknown size type: {sizeType}")
+        };
+        asciiArt.ShouldMatchApproved(x => x.NoDiff().WithDiscriminator(sizeType));
+    }
+
+    [Fact]
+    public void pdf_renderer()
+    {
+        var qrCode = new PdfByteQRCode(_sharedQrCodeData);
+        var pdfBytes = qrCode.GetGraphic(10);
+        pdfBytes.ShouldMatchApproved("pdf");
+    }
+
+    [Fact]
+    public void postscript_renderer()
+    {
+        var qrCode = new PostscriptQRCode(_sharedQrCodeData);
+        var postscript = qrCode.GetGraphic(10);
+        postscript.ShouldMatchApproved(x => x.NoDiff().WithFileExtension("ps"));
+    }
+
+    [Fact]
+    public void black_module_position()
+    {
+        // The black module in a QR code is always at position (4*version + 9, 8) + (4,4) due to the quiet zone
+        // For our test QR code (version 1), it should be at (13, 8)
+        // If transposed, it would be at (8, 13)
+        var version = _sharedQrCodeData.Version;
+        var expectedRow = 4 * version + 9 + 4;
+        var expectedCol = 8 + 4;
+        var transposedRow = expectedCol;
+        var transposedCol = expectedRow;
+
+        // Verify the black module is at the expected position
+        _sharedQrCodeData.ModuleMatrix[expectedRow][expectedCol].ShouldBeTrue(
+            $"Black module should be at position ({expectedRow}, {expectedCol})");
+
+        // Verify it's NOT at the transposed position (unless they happen to be the same)
+        if (expectedRow != transposedCol || expectedCol != transposedRow)
+        {
+            _sharedQrCodeData.ModuleMatrix[transposedRow][transposedCol].ShouldBeFalse(
+                $"Black module should NOT be at transposed position ({transposedRow}, {transposedCol})");
+        }
+    }
+
+#if SYSTEM_DRAWING
+    [Fact]
+    public void black_module_reference()
+    {
+        // Create a QR code data with the same size as our test matrix
+        // but with only a single black module at the expected black module position
+        var version = _sharedQrCodeData.Version;
+        var blackModuleRow = 4 * version + 9 + 4;
+        var blackModuleCol = 8 + 4;
+
+        // Create a minimal QRCodeData with just the black module
+        var referenceData = new QRCodeData(version, addPadding: true);
+
+        // Set only the black module position to true
+        referenceData.ModuleMatrix[blackModuleRow][blackModuleCol] = true;
+
+        // Render this reference image for human verification
+        var qrCode = new QRCode(referenceData);
+        using var bitmap = qrCode.GetGraphic(10);
+        bitmap.ShouldMatchApproved();
+    }
+#endif
+}