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 });
+    }
+}