Added random test generator

Credit/IRandomGenerator.cs

+namespace UnitTests;
+
+public interface IRandomGenerator
+{
+    long Roll();
+}
+
+public class ConcreteRandomGenerator : IRandomGenerator
+{
+    public long Roll()
+    {
+        return new Random().NextInt64(1, 6);
+    }
+}
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Credit/obj/Debug/net6.0/nCrunchTemp_76d0082b-b52c-4751-99c1-848b2536a8ad.GlobalUsings.g.cs

+// <auto-generated/>
+global using global::System;
+global using global::System.Collections.Generic;
+global using global::System.IO;
+global using global::System.Linq;
+global using global::System.Net.Http;
+global using global::System.Threading;
+global using global::System.Threading.Tasks;

Credit/obj/Debug/net6.0/nCrunchTemp_d1ea7fad-5bcc-4eee-98c4-2f2950cbb4bd.GlobalUsings.g.cs

+// <auto-generated/>
+global using global::System;
+global using global::System.Collections.Generic;
+global using global::System.IO;
+global using global::System.Linq;
+global using global::System.Net.Http;
+global using global::System.Threading;
+global using global::System.Threading.Tasks;

UnitTests/DiceRollTest.cs

+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+using NFluent;
+
+namespace UnitTests;
+public class DiceRollTest
+{
+    [Fact]
+    public void ShouldReturn8whenRolled4()
+    {
+        var stubGenerator = new StubGenerator(4);
+
+        var result = new RandomUsecase(stubGenerator).Roll();
+
+        Check.That(8).Equals(result);
+    }
+
+    [Fact]
+    public void ShouldReturn18whenRolled6()
+    {
+        var stubGenerator = new StubGenerator(6);
+
+        var result = new RandomUsecase(stubGenerator).Roll();
+
+        Check.That(18).Equals(result);
+    }
+}

UnitTests/RandomUsecase.cs

+namespace UnitTests;
+
+internal class RandomUsecase
+{
+    public IRandomGenerator RandomGenerator { get; set; }
+
+    public RandomUsecase(IRandomGenerator randomGenerator)
+    {
+        RandomGenerator = randomGenerator;
+    }
+
+    public long Roll()
+    {
+        long rolledvalue = RandomGenerator.Roll(); 
+        if (rolledvalue == 6) {
+            return 18;
+        }
+
+       return rolledvalue * 2 ;
+    }
+}
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