finally

Minint.Tests/FragmentServiceTests.cs

@@ -0,0 +1,68 @@
+using Minint.Core.Models;
+using Minint.Core.Services.Impl;
+
+namespace Minint.Tests;
+
+public class FragmentServiceTests
+{
+    private readonly FragmentService _fragment = new();
+
+    [Fact]
+    public void CopyFragment_SameDocument_CopiesPixels()
+    {
+        var doc = new MinintDocument("test");
+        var red = new RgbaColor(255, 0, 0, 255);
+        doc.EnsureColorCached(red);
+
+        var src = new MinintLayer("src", 16);
+        src.Pixels[0] = 1; // (0,0) = red
+        src.Pixels[1] = 1; // (1,0) = red
+        doc.Layers.Add(src);
+
+        var dst = new MinintLayer("dst", 16);
+        doc.Layers.Add(dst);
+
+        _fragment.CopyFragment(doc, 0, 0, 0, 2, 1, doc, 1, 2, 2, 4, 4);
+
+        Assert.Equal(1, dst.Pixels[2 * 4 + 2]); // (2,2)
+        Assert.Equal(1, dst.Pixels[2 * 4 + 3]); // (3,2)
+    }
+
+    [Fact]
+    public void CopyFragment_DifferentDocuments_MergesPalette()
+    {
+        var srcDoc = new MinintDocument("src");
+        var blue = new RgbaColor(0, 0, 255, 255);
+        int blueIdx = srcDoc.EnsureColorCached(blue);
+        var srcLayer = new MinintLayer("L1", 4);
+        srcLayer.Pixels[0] = blueIdx;
+        srcDoc.Layers.Add(srcLayer);
+
+        var dstDoc = new MinintDocument("dst");
+        var dstLayer = new MinintLayer("L1", 4);
+        dstDoc.Layers.Add(dstLayer);
+
+        _fragment.CopyFragment(srcDoc, 0, 0, 0, 1, 1, dstDoc, 0, 0, 0, 2, 2);
+
+        int dstBlueIdx = dstDoc.FindColorCached(blue);
+        Assert.True(dstBlueIdx > 0);
+        Assert.Equal(dstBlueIdx, dstLayer.Pixels[0]);
+    }
+
+    [Fact]
+    public void CopyFragment_TransparentPixels_Skipped()
+    {
+        var doc = new MinintDocument("test");
+        var src = new MinintLayer("src", 4); // all zeros (transparent)
+        doc.Layers.Add(src);
+
+        var dst = new MinintLayer("dst", 4);
+        Array.Fill(dst.Pixels, 0);
+        dst.Pixels[0] = 0; // explicitly 0
+        doc.Layers.Add(dst);
+
+        _fragment.CopyFragment(doc, 0, 0, 0, 2, 2, doc, 1, 0, 0, 2, 2);
+
+        Assert.Equal(0, dst.Pixels[0]); // stays transparent
+    }
+}