Moar tests!

Raccoon.Ninja.Domain.Core.Tests/Calculators/Abstractions/BaseCalculatorHandlerTests.cs

@@ -1,6 +1,7 @@
 using Raccoon.Ninja.Domain.Core.Calculators;
 using Raccoon.Ninja.Domain.Core.Calculators.Abstractions;
 using Raccoon.Ninja.Domain.Core.Calculators.Handlers;
+using Raccoon.Ninja.TestHelpers;
 using Raccoon.Ninja.TestHelpers.MockClasses.Handlers;
 
 namespace Raccoon.Ninja.Domain.Core.Tests.Calculators.Abstractions;
@@ -38,4 +39,22 @@ public void HandleNext_WithMultipleHandlers_ShouldCallNextHandler()
         // Assert
         result.Average.Should().Be(expectedAverage);
     }
+
+    [Theory]
+    [MemberData(nameof(TheoryGenerator.InvalidFloatListsWithNull), MemberType = typeof(TheoryGenerator))]
+    public void HandleNext_WhenDataIsInvalid_ShouldReturnError(IList<float> glucoseReadings)
+    {
+        // Arrange
+        var data = Generators.CalculationDataMockSingle(glucoseReadings);
+        var handler = new DoNothingMockCalculator();
+
+        // Act
+        var result = handler.Handle(data);
+
+        // Assert
+        var status = result.Status;
+        status.Success.Should().BeFalse();
+        status.FirstFailedStep.Should().Be(nameof(DoNothingMockCalculator));
+        status.Message.Should().Be("No glucose values were provided.");
+    }
 }

Raccoon.Ninja.TestHelpers/MockClasses/Handlers/DoNothingMockCalculator.cs

@@ -0,0 +1,12 @@
+using Raccoon.Ninja.Domain.Core.Calculators;
+using Raccoon.Ninja.Domain.Core.Calculators.Abstractions;
+
+namespace Raccoon.Ninja.TestHelpers.MockClasses.Handlers;
+
+public class DoNothingMockCalculator: BaseCalculatorHandler
+{
+    protected override CalculationData RunCalculation(CalculationData data)
+    {
+        return data;
+    }
+}