MathUtils added

Recyclable.CollectionsTests/MathUtilsTests.cs

@@ -0,0 +1,32 @@
+using FluentAssertions;
+using Recyclable.Collections;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Recyclable.CollectionsTests
+{
+	public class MathUtilsTests
+	{
+		[Theory]
+		[InlineData(int.MaxValue / 1024, int.MaxValue / 10 / 1024)]
+		public void DivMod(long testNumber, int blockSize)
+		{
+			for (var testCase = testNumber; testCase >= 0; testCase--)
+			{
+				// Prepare
+				var expectedResult = testCase / blockSize;
+				var expectedRemainder = testCase % blockSize;
+
+				// Act
+				var actualResult = MathUtils.DivMod(testCase, blockSize, out long actualRemainder);
+
+				// Validate
+				_ = actualResult.Should().Be(expectedResult);
+				_ = actualRemainder.Should().Be(expectedRemainder);
+			}
+		}
+	}
+}