Index: Ringtoets/DuneErosion/test/Ringtoets.DuneErosion.Data.Test/DuneErosionFailureMechanismExtensionsTest.cs
===================================================================
diff -u -r861341a7835c17ca6309ff1b6e0b8fe2269b5c0f -r32061d48745c5325becd9adac3118d976587b3b6
--- Ringtoets/DuneErosion/test/Ringtoets.DuneErosion.Data.Test/DuneErosionFailureMechanismExtensionsTest.cs	(.../DuneErosionFailureMechanismExtensionsTest.cs)	(revision 861341a7835c17ca6309ff1b6e0b8fe2269b5c0f)
+++ Ringtoets/DuneErosion/test/Ringtoets.DuneErosion.Data.Test/DuneErosionFailureMechanismExtensionsTest.cs	(.../DuneErosionFailureMechanismExtensionsTest.cs)	(revision 32061d48745c5325becd9adac3118d976587b3b6)
@@ -21,7 +21,11 @@
 
 using System;
 using System.Linq;
+using Core.Common.TestUtil;
 using NUnit.Framework;
+using Rhino.Mocks;
+using Ringtoets.Common.Data.AssessmentSection;
+using Ringtoets.Common.Data.Contribution;
 using Ringtoets.Common.Data.Hydraulics;
 using Ringtoets.DuneErosion.Data.TestUtil;
 
@@ -105,5 +109,97 @@
             // Assert
             CollectionAssert.IsEmpty(failureMechanism.DuneLocations);
         }
+
+        [Test]
+        public void GetMechanismSpecificNorm_FailureMechanismNull_ThrowArgumentNullException()
+        {
+            // Setup
+            var mocks = new MockRepository();
+            var assessmentSection = mocks.Stub<IAssessmentSection>();
+            mocks.ReplayAll();
+
+            // Call
+            TestDelegate test = () => DuneErosionFailureMechanismExtensions.GetMechanismSpecificNorm(null, assessmentSection);
+
+            // Assert
+            var exception = Assert.Throws<ArgumentNullException>(test);
+            Assert.AreEqual("failureMechanism", exception.ParamName);
+            mocks.VerifyAll();
+        }
+
+        [Test]
+        public void GetMechanismSpecificNorm_AssessmentSectionNull_ThrowArgumentNullException()
+        {
+            // Setup
+            var failureMechanism = new DuneErosionFailureMechanism();
+
+            // Call
+            TestDelegate test = () => failureMechanism.GetMechanismSpecificNorm(null);
+
+            // Assert
+            var exception = Assert.Throws<ArgumentNullException>(test);
+            Assert.AreEqual("assessmentSection", exception.ParamName);
+        }
+
+        [Test]
+        public void GetMechanismSpecificNorm_WithZeroContributionForFailureMechanism_ThrowsArgumentException()
+        {
+            // Setup
+            var failureMechanism = new DuneErosionFailureMechanism
+            {
+                Contribution = 0
+            };
+
+            var mocks = new MockRepository();
+            var assessmentSection = mocks.StrictMock<IAssessmentSection>();
+            assessmentSection.Stub(a => a.GetFailureMechanisms()).Return(new[]
+            {
+                failureMechanism
+            });
+            assessmentSection.Stub(a => a.FailureMechanismContribution).Return(new FailureMechanismContribution(new[]
+            {
+                failureMechanism
+            }, 1, 1.0 / 300));
+            mocks.ReplayAll();
+
+            // Call
+            TestDelegate action = () => failureMechanism.GetMechanismSpecificNorm(assessmentSection);
+
+            // Assert
+            const string expectedMessage = "De bijdrage van dit toetsspoor is nul. Daardoor kunnen de berekeningen niet worden uitgevoerd.";
+            TestHelper.AssertThrowsArgumentExceptionAndTestMessage<ArgumentException>(action, expectedMessage);
+            mocks.VerifyAll();
+        }
+
+        [Test]
+        public void GetMechanismSpecificNorm_WithValidData_ReturnMechanismSpecificNorm()
+        {
+            // Setup
+            const double norm = 1.0 / 200;
+            const double contribution = 10;
+            var failureMechanism = new DuneErosionFailureMechanism
+            {
+                Contribution = contribution
+            };
+
+            var mocks = new MockRepository();
+            var assessmentSection = mocks.StrictMock<IAssessmentSection>();
+            assessmentSection.Stub(a => a.GetFailureMechanisms()).Return(new[]
+            {
+                failureMechanism
+            });
+            assessmentSection.Stub(a => a.FailureMechanismContribution).Return(new FailureMechanismContribution(new[]
+            {
+                failureMechanism
+            }, 1, norm));
+            mocks.ReplayAll();
+
+            // Call
+            double mechanismSpecificNorm = failureMechanism.GetMechanismSpecificNorm(assessmentSection);
+
+            // Assert
+            Assert.AreEqual(0.0005375, mechanismSpecificNorm);
+            mocks.VerifyAll();
+        }
     }
 }
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