From c1811af5d511a3304941304aed532da780ca629d Mon Sep 17 00:00:00 2001
From: AJ Isaacs <ajisaacs27@gmail.com>
Date: Mon, 9 Mar 2026 20:43:55 -0400
Subject: [PATCH] test: add RemnantFillTests for remnant area filling

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
---
 OpenNest.Test/RemnantFillTests.cs | 97 +++++++++++++++++++++++++++++++
 1 file changed, 97 insertions(+)
 create mode 100644 OpenNest.Test/RemnantFillTests.cs

diff --git a/OpenNest.Test/RemnantFillTests.cs b/OpenNest.Test/RemnantFillTests.cs
new file mode 100644
index 0000000..c19a329
--- /dev/null
+++ b/OpenNest.Test/RemnantFillTests.cs
@@ -0,0 +1,97 @@
+using OpenNest.Geometry;
+using Xunit;
+using Xunit.Abstractions;
+
+namespace OpenNest.Test;
+
+public class RemnantFillTests
+{
+    private readonly ITestOutputHelper _output;
+
+    public RemnantFillTests(ITestOutputHelper output)
+    {
+        _output = output;
+    }
+
+    [SkippableFact]
+    [Trait("Category", "Remnant")]
+    public void N0308_017_PT02_RemnantFillsAtLeast10()
+    {
+        Skip.IfNot(TestData.IsAvailable, TestData.SkipReason);
+
+        var nest = TestData.LoadNest("N0308-017.zip");
+        var plate = nest.Plates[0];
+        var pt02 = nest.Drawings.First(d => d.Name.Contains("PT02"));
+        var remnant = plate.GetRemnants()[0];
+
+        _output.WriteLine($"Remnant: ({remnant.X:F2},{remnant.Y:F2}) {remnant.Width:F2}x{remnant.Height:F2}");
+
+        var countBefore = plate.Parts.Count;
+        var engine = new NestEngine(plate);
+        var sw = System.Diagnostics.Stopwatch.StartNew();
+        engine.Fill(new NestItem { Drawing = pt02, Quantity = 0 }, remnant);
+        sw.Stop();
+
+        var added = plate.Parts.Count - countBefore;
+        _output.WriteLine($"Added: {added} parts | Time: {sw.ElapsedMilliseconds}ms");
+
+        Assert.True(added >= 10, $"Expected >= 10 parts in remnant, got {added}");
+
+        var newParts = plate.Parts.Skip(countBefore).ToList();
+        AssertNoOverlaps(newParts);
+        AssertNoCrossOverlaps(plate.Parts.Take(countBefore).ToList(), newParts);
+    }
+
+    [SkippableFact]
+    [Trait("Category", "Remnant")]
+    public void N0308_008_HingePlate_RemnantFillsAtLeast8()
+    {
+        Skip.IfNot(TestData.IsAvailable, TestData.SkipReason);
+
+        var nest = TestData.LoadNest("N0308-008.zip");
+        var plate = nest.Plates[0];
+        var hinge = nest.Drawings.First(d => d.Name.Contains("HINGE PLATE #2"));
+        var remnants = plate.GetRemnants();
+
+        _output.WriteLine($"Remnant 0: ({remnants[0].X:F2},{remnants[0].Y:F2}) {remnants[0].Width:F2}x{remnants[0].Height:F2}");
+
+        var countBefore = plate.Parts.Count;
+        var engine = new NestEngine(plate);
+        var sw = System.Diagnostics.Stopwatch.StartNew();
+        engine.Fill(new NestItem { Drawing = hinge, Quantity = 0 }, remnants[0]);
+        sw.Stop();
+
+        var added = plate.Parts.Count - countBefore;
+        _output.WriteLine($"Added: {added} parts | Time: {sw.ElapsedMilliseconds}ms");
+
+        Assert.True(added >= 8, $"Expected >= 8 parts in remnant, got {added}");
+
+        var newParts = plate.Parts.Skip(countBefore).ToList();
+        AssertNoOverlaps(newParts);
+        AssertNoCrossOverlaps(plate.Parts.Take(countBefore).ToList(), newParts);
+    }
+
+    private void AssertNoOverlaps(List<Part> parts)
+    {
+        for (var i = 0; i < parts.Count; i++)
+        {
+            for (var j = i + 1; j < parts.Count; j++)
+            {
+                if (parts[i].Intersects(parts[j], out _))
+                    Assert.Fail($"Overlap detected: part [{i}] vs [{j}]");
+            }
+        }
+    }
+
+    private void AssertNoCrossOverlaps(List<Part> existing, List<Part> added)
+    {
+        for (var i = 0; i < existing.Count; i++)
+        {
+            for (var j = 0; j < added.Count; j++)
+            {
+                if (existing[i].Intersects(added[j], out _))
+                    Assert.Fail($"Cross-overlap: existing [{i}] vs added [{j}]");
+            }
+        }
+    }
+}