Initial commit.

PerfectNumbers.Core.Tests/PrimeTester/PrimeTesterGcdTests.cs

@@ -0,0 +1,25 @@
+using FluentAssertions;
+using Xunit;
+
+namespace PerfectNumbers.Core.Tests;
+
+[Trait("Category", "Fast")]
+public class PrimeTesterGcdTests
+{
+    [Theory]
+    [InlineData(81UL, true)]
+    [InlineData(101UL, false)]
+    public void SharesFactorWithMaxExponent_detects_gcd(ulong n, bool expected)
+    {
+        PrimeTester.SharesFactorWithMaxExponent(n).Should().Be(expected);
+    }
+
+    [Fact]
+    public void SharesFactorWithMaxExponentBatch_filters_values()
+    {
+        ulong[] values = [81UL, 101UL];
+        Span<byte> results = stackalloc byte[values.Length];
+        PrimeTester.SharesFactorWithMaxExponentBatch(values, results);
+        results.ToArray().Should().Equal(new byte[] { 1, 0 });
+    }
+}

PerfectNumbers.Core.Tests/PrimeTester/PrimeTesterIsPrimeTests.cs

@@ -0,0 +1,39 @@
+using FluentAssertions;
+using PerfectNumbers.Core.Gpu;
+using Xunit;
+
+namespace PerfectNumbers.Core.Tests;
+
+public class PrimeTesterIsPrimeTests
+{
+    [Theory]
+    [Trait("Category", "Fast")]
+    [InlineData(1UL, false)]
+    [InlineData(2UL, true)]
+    [InlineData(3UL, true)]
+    [InlineData(4UL, false)]
+    [InlineData(7UL, true)]
+    [InlineData(97UL, true)]
+    [InlineData(121UL, false)]
+    public void IsPrime_returns_expected_results(ulong n, bool expected)
+    {
+        var tester = new PrimeTester();
+
+        tester.IsPrime(n, CancellationToken.None).Should().Be(expected);
+    }
+
+    [Fact]
+    [Trait("Category", "Fast")]
+    public void IsPrimeGpu_falls_back_to_cpu_when_forced()
+    {
+        var tester = new PrimeTester();
+        GpuContextPool.ForceCpu = true;
+
+        tester.IsPrimeGpu(11UL, CancellationToken.None).Should().BeTrue();
+
+        tester.IsPrimeGpu(12UL, CancellationToken.None).Should().BeFalse();
+
+        GpuContextPool.ForceCpu = false;
+    }
+}
+