refactor(engine): extract ShrinkFiller from StripNestEngine

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-03-16 22:28:24 -04:00
parent 31dbbbeedc
commit 094b1e9f00
2 changed files with 174 additions and 0 deletions
@@ -0,0 +1,99 @@
+using OpenNest.Geometry;
+
+namespace OpenNest.Tests;
+
+public class ShrinkFillerTests
+{
+    private static Drawing MakeSquareDrawing(double size)
+    {
+        var pgm = new OpenNest.CNC.Program();
+        pgm.Codes.Add(new OpenNest.CNC.RapidMove(new Vector(0, 0)));
+        pgm.Codes.Add(new OpenNest.CNC.LinearMove(new Vector(size, 0)));
+        pgm.Codes.Add(new OpenNest.CNC.LinearMove(new Vector(size, size)));
+        pgm.Codes.Add(new OpenNest.CNC.LinearMove(new Vector(0, size)));
+        pgm.Codes.Add(new OpenNest.CNC.LinearMove(new Vector(0, 0)));
+        return new Drawing("square", pgm);
+    }
+
+    [Fact]
+    public void Shrink_ReducesDimension_UntilCountDrops()
+    {
+        var drawing = MakeSquareDrawing(10);
+        var item = new NestItem { Drawing = drawing };
+        var box = new Box(0, 0, 100, 50);
+
+        Func<NestItem, Box, List<Part>> fillFunc = (ni, b) =>
+        {
+            var plate = new Plate(b.Width, b.Length);
+            var engine = new DefaultNestEngine(plate);
+            return engine.Fill(ni, b, null, System.Threading.CancellationToken.None);
+        };
+
+        var result = ShrinkFiller.Shrink(fillFunc, item, box, 1.0, ShrinkAxis.Height);
+
+        Assert.NotNull(result);
+        Assert.True(result.Parts.Count > 0);
+        Assert.True(result.Dimension <= 50, "Dimension should be <= original");
+        Assert.True(result.Dimension > 0);
+    }
+
+    [Fact]
+    public void Shrink_Width_ReducesHorizontally()
+    {
+        var drawing = MakeSquareDrawing(10);
+        var item = new NestItem { Drawing = drawing };
+        var box = new Box(0, 0, 100, 50);
+
+        Func<NestItem, Box, List<Part>> fillFunc = (ni, b) =>
+        {
+            var plate = new Plate(b.Width, b.Length);
+            var engine = new DefaultNestEngine(plate);
+            return engine.Fill(ni, b, null, System.Threading.CancellationToken.None);
+        };
+
+        var result = ShrinkFiller.Shrink(fillFunc, item, box, 1.0, ShrinkAxis.Width);
+
+        Assert.NotNull(result);
+        Assert.True(result.Parts.Count > 0);
+        Assert.True(result.Dimension <= 100);
+    }
+
+    [Fact]
+    public void Shrink_RespectsMaxIterations()
+    {
+        var callCount = 0;
+        Func<NestItem, Box, List<Part>> fillFunc = (ni, b) =>
+        {
+            callCount++;
+            return new List<Part> { TestHelpers.MakePartAt(0, 0, 5) };
+        };
+
+        var item = new NestItem { Drawing = MakeSquareDrawing(5) };
+        var box = new Box(0, 0, 100, 100);
+
+        ShrinkFiller.Shrink(fillFunc, item, box, 1.0, ShrinkAxis.Height, maxIterations: 3);
+
+        // 1 initial + up to 3 shrink iterations = max 4 calls
+        Assert.True(callCount <= 4);
+    }
+
+    [Fact]
+    public void Shrink_RespectsCancellation()
+    {
+        var cts = new System.Threading.CancellationTokenSource();
+        cts.Cancel();
+
+        var drawing = MakeSquareDrawing(10);
+        var item = new NestItem { Drawing = drawing };
+        var box = new Box(0, 0, 100, 50);
+
+        Func<NestItem, Box, List<Part>> fillFunc = (ni, b) =>
+            new List<Part> { TestHelpers.MakePartAt(0, 0, 10) };
+
+        var result = ShrinkFiller.Shrink(fillFunc, item, box, 1.0,
+            ShrinkAxis.Height, token: cts.Token);
+
+        Assert.NotNull(result);
+        Assert.True(result.Parts.Count > 0);
+    }
+}