finally

Minint.Tests/DrawingTests.cs

@@ -0,0 +1,63 @@
+using Minint.Core.Models;
+using Minint.Core.Services.Impl;
+
+namespace Minint.Tests;
+
+public class DrawingTests
+{
+    private readonly DrawingService _drawing = new();
+
+    [Fact]
+    public void ApplyBrush_Radius0_SetsSinglePixel()
+    {
+        var layer = new MinintLayer("L1", 9);
+        _drawing.ApplyBrush(layer, 1, 1, 0, 1, 3, 3);
+
+        Assert.Equal(1, layer.Pixels[1 * 3 + 1]);
+        Assert.Equal(0, layer.Pixels[0]); // (0,0) untouched
+    }
+
+    [Fact]
+    public void ApplyBrush_Radius1_SetsCircle()
+    {
+        var layer = new MinintLayer("L1", 25);
+        _drawing.ApplyBrush(layer, 2, 2, 1, 1, 5, 5);
+
+        // Center + 4 neighbors should be set
+        Assert.Equal(1, layer.Pixels[2 * 5 + 2]); // center
+        Assert.Equal(1, layer.Pixels[1 * 5 + 2]); // top
+        Assert.Equal(1, layer.Pixels[3 * 5 + 2]); // bottom
+        Assert.Equal(1, layer.Pixels[2 * 5 + 1]); // left
+        Assert.Equal(1, layer.Pixels[2 * 5 + 3]); // right
+    }
+
+    [Fact]
+    public void ApplyEraser_SetsToZero()
+    {
+        var layer = new MinintLayer("L1", 9);
+        Array.Fill(layer.Pixels, 5);
+        _drawing.ApplyEraser(layer, 1, 1, 0, 3, 3);
+
+        Assert.Equal(0, layer.Pixels[1 * 3 + 1]);
+        Assert.Equal(5, layer.Pixels[0]); // untouched
+    }
+
+    [Fact]
+    public void GetBrushMask_Radius0_SinglePixel()
+    {
+        var mask = _drawing.GetBrushMask(2, 2, 0, 5, 5);
+        Assert.Single(mask);
+        Assert.Equal((2, 2), mask[0]);
+    }
+
+    [Fact]
+    public void GetBrushMask_OutOfBounds_Clamped()
+    {
+        var mask = _drawing.GetBrushMask(0, 0, 2, 3, 3);
+        Assert.All(mask, p =>
+        {
+            Assert.InRange(p.X, 0, 2);
+            Assert.InRange(p.Y, 0, 2);
+        });
+    }
+}