Initial commit.

PerfectNumbers.Core.Tests/Gpu/LucasLehmerPrimeTesterTests.cs

@@ -0,0 +1,53 @@
+using FluentAssertions;
+using PerfectNumbers.Core.Gpu;
+using Xunit;
+
+namespace PerfectNumbers.Core.Tests.Gpu;
+
+[Trait("Category", "Slow")]
+public class LucasLehmerPrimeTesterTests
+{
+    [Theory]
+    [InlineData(3UL, true)]
+    [InlineData(5UL, true)]
+    [InlineData(11UL, false)]
+    [Trait("Category", "Fast")]
+    public void IsMersennePrime_gpu_returns_expected_results(ulong p, bool expected)
+    {
+        new MersenneNumberLucasLehmerGpuTester().IsMersennePrime(p).Should().Be(expected);
+    }
+
+    [Fact]
+    [Trait("Category", "Fast")]
+    public void IsMersennePrime_gpu_large_exponent_without_cpu_fallback()
+    {
+        // Use a modest exponent that still exercises the NTT path while keeping
+        // runtime short enough for the unit test environment.
+        const ulong exponent = 128UL;
+        var tester = new MersenneNumberLucasLehmerGpuTester();
+        tester.WarmUpNttParameters(exponent);
+        tester.IsMersennePrime(exponent).Should().BeFalse();
+    }
+
+    [Theory]
+    [InlineData(132UL)]
+    [InlineData(1000UL)]
+    [Trait("Category", "Slow")]
+    public void WarmUpNttParameters_populates_cache_for_large_exponent(ulong exponent)
+    {
+        var tester = new MersenneNumberLucasLehmerGpuTester();
+        tester.WarmUpNttParameters(exponent);
+        tester.IsMersennePrime(exponent).Should().BeFalse();
+    }
+
+    [Theory]
+    [InlineData(3UL, true)]
+    [InlineData(5UL, true)]
+    [InlineData(11UL, false)]
+    [Trait("Category", "Fast")]
+    public void IsMersennePrime_cpu_matches_expected_results(ulong p, bool expected)
+    {
+        new MersenneNumberLucasLehmerCpuTester().IsPrime(p).Should().Be(expected);
+    }
+}
+