Initial commit.

PerfectNumbers.Core.Tests/RationalHelperTests.cs

@@ -0,0 +1,53 @@
+using System.Numerics;
+using FluentAssertions;
+using PeterO.Numbers;
+using Xunit;
+
+namespace PerfectNumbers.Core.Tests;
+
+public class RationalHelperTests
+{
+    [Fact]
+    [Trait("Category", "Fast")]
+    public void FromDoubleRounded_ReducesFraction()
+    {
+        ERational result = RationalHelper.FromDoubleRounded(0.75);
+
+        result.Numerator.ToInt32Checked().Should().Be(3);
+        result.Denominator.ToInt32Checked().Should().Be(4);
+    }
+
+    [Fact]
+    [Trait("Category", "Fast")]
+    public void ToEInteger_ReturnsMatchingValue()
+    {
+        BigInteger value = BigInteger.Parse("12345678901234567890");
+
+        EInteger einteger = RationalHelper.ToEInteger(value);
+
+        einteger.ToString().Should().Be(value.ToString());
+    }
+
+    [Fact]
+    [Trait("Category", "Fast")]
+    public void FloorToUInt64_ReturnsFloor()
+    {
+        ERational value = ERational.Create(5, 2);
+
+        ulong result = RationalHelper.FloorToUInt64(value);
+
+        result.Should().Be(2UL);
+    }
+
+    [Fact]
+    [Trait("Category", "Fast")]
+    public void CeilingToUInt64_RoundsUpWhenFractional()
+    {
+        ERational fractional = ERational.Create(5, 2);
+        ERational integral = ERational.Create(6, 2);
+
+        RationalHelper.CeilingToUInt64(fractional).Should().Be(3UL);
+        RationalHelper.CeilingToUInt64(integral).Should().Be(3UL);
+    }
+}
+