Initial commit.

PerfectNumbers.Core.Tests/MersennePrimeFactorTester/MersennePrimeFactorTesterTests.cs

@@ -0,0 +1,29 @@
+using FluentAssertions;
+using Xunit;
+
+namespace PerfectNumbers.Core.Tests;
+
+public class MersennePrimeFactorTesterTests
+{
+    [Theory]
+    [InlineData(5UL, 31UL, true)]
+    [InlineData(11UL, 23UL, true)]
+    [InlineData(11UL, 89UL, true)]
+    [InlineData(5UL, 7UL, false)]
+    [InlineData(7UL, 17UL, false)]
+    [InlineData(11UL, 331UL, false)]
+    [Trait("Category", "Fast")]
+    public void IsPrimeFactor_identifies_divisibility(ulong p, ulong q, bool expected)
+    {
+        MersennePrimeFactorTester.IsPrimeFactor(p, q, CancellationToken.None).Should().Be(expected);
+    }
+
+    [Fact]
+    [Trait("Category", "Slow")]
+    public void GetOrderOf2ModPrime_handles_large_divisors()
+    {
+        UInt128 q = UInt128.Parse("618970019642690137449562111");
+        MersennePrimeFactorTester.GetOrderOf2ModPrime(q, CancellationToken.None)
+            .Should().Be((UInt128)89);
+    }
+}