Fix most of verification findings

SysML2.NET.Tests/Extend/ConjugatedPortTypingExtensionsTestFixture.cs

@@ -1,20 +1,20 @@
 // -------------------------------------------------------------------------------------------------
 // <copyright file="ConjugatedPortTypingExtensionsTestFixture.cs" company="Starion Group S.A.">
-//
-//   Copyright 2022-2026 Starion Group S.A.
-//
+// 
+//   Copyright (C) 2022-2026 Starion Group S.A.
+// 
 //   Licensed under the Apache License, Version 2.0 (the "License");
 //   you may not use this file except in compliance with the License.
 //   You may obtain a copy of the License at
-//
+// 
 //        http://www.apache.org/licenses/LICENSE-2.0
-//
+// 
 //    Unless required by applicable law or agreed to in writing, software
 //    distributed under the License is distributed on an "AS IS" BASIS,
 //    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 //    See the License for the specific language governing permissions and
 //    limitations under the License.
-//
+// 
 // </copyright>
 // ------------------------------------------------------------------------------------------------
 
@@ -26,6 +26,7 @@ namespace SysML2.NET.Tests.Extend
 
     using SysML2.NET.Core.POCO.Root.Namespaces;
     using SysML2.NET.Core.POCO.Systems.Ports;
+    using SysML2.NET.Exceptions;
     using SysML2.NET.Extensions;
 
     [TestFixture]
@@ -36,10 +37,15 @@ public void VerifyComputePortDefinition()
         {
             Assert.That(() => ((IConjugatedPortTyping)null).ComputePortDefinition(), Throws.TypeOf<ArgumentNullException>());
 
-            // No ConjugatedPortDefinition -> the null-safe navigation short-circuits to null.
+            // No ConjugatedPortDefinition -> [1..1] violation.
             var emptyConjugatedPortTyping = new ConjugatedPortTyping();
 
-            Assert.That(emptyConjugatedPortTyping.ComputePortDefinition(), Is.Null);
+            Assert.That(emptyConjugatedPortTyping.ComputePortDefinition, Throws.TypeOf<IncompleteModelException>());
+
+            // A ConjugatedPortDefinition with no ownership chain resolves no originalPortDefinition.
+            var unownedConjugatedPortTyping = new ConjugatedPortTyping { ConjugatedPortDefinition = new ConjugatedPortDefinition() };
+
+            Assert.That(unownedConjugatedPortTyping.ComputePortDefinition, Throws.TypeOf<IncompleteModelException>());
 
             // Positive case: the ConjugatedPortDefinition's originalPortDefinition derives from its
             // owningMembership -> membershipOwningNamespace, which must be a PortDefinition. Wire that

SysML2.NET.Tests/Extend/CrossSubsettingExtensionsTestFixture.cs

@@ -1,20 +1,20 @@
 // -------------------------------------------------------------------------------------------------
 // <copyright file="CrossSubsettingExtensionsTestFixture.cs" company="Starion Group S.A.">
-//
-//   Copyright 2022-2026 Starion Group S.A.
-//
+// 
+//   Copyright (C) 2022-2026 Starion Group S.A.
+// 
 //   Licensed under the Apache License, Version 2.0 (the "License");
 //   you may not use this file except in compliance with the License.
 //   You may obtain a copy of the License at
-//
+// 
 //        http://www.apache.org/licenses/LICENSE-2.0
-//
+// 
 //    Unless required by applicable law or agreed to in writing, software
 //    distributed under the License is distributed on an "AS IS" BASIS,
 //    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 //    See the License for the specific language governing permissions and
 //    limitations under the License.
-//
+// 
 // </copyright>
 // ------------------------------------------------------------------------------------------------
 
@@ -27,6 +27,7 @@ namespace SysML2.NET.Tests.Extend
     using SysML2.NET.Core.POCO.Core.Features;
     using SysML2.NET.Core.POCO.Root.Elements;
     using SysML2.NET.Core.POCO.Root.Namespaces;
+    using SysML2.NET.Exceptions;
 
     [TestFixture]
     public class CrossSubsettingExtensionsTestFixture
@@ -38,7 +39,7 @@ public void VerifyComputeCrossingFeature()
 
             var crossSubsetting = new CrossSubsetting();
 
-            Assert.That(crossSubsetting.ComputeCrossingFeature(), Is.Null);
+            Assert.That(crossSubsetting.ComputeCrossingFeature, Throws.TypeOf<IncompleteModelException>());
 
             var feature = new Feature();
 
@@ -51,7 +52,7 @@ public void VerifyComputeCrossingFeature()
 
             ((IContainedRelationship)nonFeatureCrossSubsetting).OwningRelatedElement = nonFeatureOwner;
 
-            Assert.That(nonFeatureCrossSubsetting.ComputeCrossingFeature(), Is.Null);
+            Assert.That(nonFeatureCrossSubsetting.ComputeCrossingFeature, Throws.TypeOf<IncompleteModelException>());
         }
     }
 }

SysML2.NET.Tests/Extend/DifferencingExtensionsTestFixture.cs

@@ -1,20 +1,20 @@
 // -------------------------------------------------------------------------------------------------
 // <copyright file="DifferencingExtensionsTestFixture.cs" company="Starion Group S.A.">
-//
-//   Copyright 2022-2026 Starion Group S.A.
-//
+// 
+//   Copyright (C) 2022-2026 Starion Group S.A.
+// 
 //   Licensed under the Apache License, Version 2.0 (the "License");
 //   you may not use this file except in compliance with the License.
 //   You may obtain a copy of the License at
-//
+// 
 //        http://www.apache.org/licenses/LICENSE-2.0
-//
+// 
 //    Unless required by applicable law or agreed to in writing, software
 //    distributed under the License is distributed on an "AS IS" BASIS,
 //    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 //    See the License for the specific language governing permissions and
 //    limitations under the License.
-//
+// 
 // </copyright>
 // ------------------------------------------------------------------------------------------------
 
@@ -27,6 +27,7 @@ namespace SysML2.NET.Tests.Extend
     using SysML2.NET.Core.POCO.Core.Types;
     using SysML2.NET.Core.POCO.Root.Elements;
     using SysML2.NET.Core.POCO.Root.Namespaces;
+    using SysML2.NET.Exceptions;
     using SysML2.NET.Extensions;
 
     using Type = SysML2.NET.Core.POCO.Core.Types.Type;
@@ -41,7 +42,7 @@ public void VerifyComputeTypeDifferenced()
 
             var emptyDifferencing = new Differencing();
 
-            Assert.That(emptyDifferencing.ComputeTypeDifferenced(), Is.Null);
+            Assert.That(emptyDifferencing.ComputeTypeDifferenced, Throws.TypeOf<IncompleteModelException>());
 
             var owningType = new Type();
             var differencing = new Differencing();
@@ -55,7 +56,7 @@ public void VerifyComputeTypeDifferenced()
 
             ((IContainedRelationship)nonTypeDifferencing).OwningRelatedElement = nonTypeOwner;
 
-            Assert.That(nonTypeDifferencing.ComputeTypeDifferenced(), Is.Null);
+            Assert.That(nonTypeDifferencing.ComputeTypeDifferenced, Throws.TypeOf<IncompleteModelException>());
         }
     }
 }

SysML2.NET.Tests/Extend/ExpressionExtensionsTestFixture.cs

@@ -218,11 +218,8 @@ public void VerifyComputeModelLevelEvaluableOperation()
 
             Assert.That(expressionNestedFeature.ComputeModelLevelEvaluableOperation([]), Is.False);
 
-            // ownedFeature with a FeatureValue — NOTE: the production code's valuation check
-            // (f.valuation == null) is a known metamodel gap (IFeature has no Valuation property).
-            // FeatureValue is IOwningMembership but NOT IFeatureMembership, so the contained Expression
-            // is not visible via ownedFeature of featureWithValuation. BRANCH_A therefore succeeds
-            // (Direction = In, ownedFeature.Count == 0) and the operation returns true.
+            // ownedFeature carrying a FeatureValue → BRANCH_A fails on the KerML §8.3.4.7.3 rule that a
+            // parameter must have no FeatureValue, and BRANCH_B fails (not a ResultExpressionMembership).
             var expressionWithValuation = new Expression();
             var featureWithValuation = new Feature { Direction = FeatureDirectionKind.In };
             var featureValue = new FeatureValue();
@@ -232,7 +229,7 @@ public void VerifyComputeModelLevelEvaluableOperation()
             var valuationMembership = new FeatureMembership();
             expressionWithValuation.AssignOwnership(valuationMembership, featureWithValuation);
 
-            Assert.That(expressionWithValuation.ComputeModelLevelEvaluableOperation([]), Is.True);
+            Assert.That(expressionWithValuation.ComputeModelLevelEvaluableOperation([]), Is.False);
 
             // BRANCH_B: ownedFeature owned via ResultExpressionMembership — passes branchB.
             // The inner Expression is empty (no specializations, no features), so its recursive

SysML2.NET.Tests/Extend/FeatureChainingExtensionsTestFixture.cs

@@ -1,20 +1,20 @@
 // -------------------------------------------------------------------------------------------------
 // <copyright file="FeatureChainingExtensionsTestFixture.cs" company="Starion Group S.A.">
-//
-//   Copyright 2022-2026 Starion Group S.A.
-//
+// 
+//   Copyright (C) 2022-2026 Starion Group S.A.
+// 
 //   Licensed under the Apache License, Version 2.0 (the "License");
 //   you may not use this file except in compliance with the License.
 //   You may obtain a copy of the License at
-//
+// 
 //        http://www.apache.org/licenses/LICENSE-2.0
-//
+// 
 //    Unless required by applicable law or agreed to in writing, software
 //    distributed under the License is distributed on an "AS IS" BASIS,
 //    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 //    See the License for the specific language governing permissions and
 //    limitations under the License.
-//
+// 
 // </copyright>
 // ------------------------------------------------------------------------------------------------
 
@@ -27,6 +27,7 @@ namespace SysML2.NET.Tests.Extend
     using SysML2.NET.Core.POCO.Core.Features;
     using SysML2.NET.Core.POCO.Root.Elements;
     using SysML2.NET.Core.POCO.Root.Namespaces;
+    using SysML2.NET.Exceptions;
 
     [TestFixture]
     public class FeatureChainingExtensionsTestFixture
@@ -38,7 +39,7 @@ public void VerifyComputeFeatureChained()
 
             var featureChaining = new FeatureChaining();
 
-            Assert.That(featureChaining.ComputeFeatureChained(), Is.Null);
+            Assert.That(featureChaining.ComputeFeatureChained, Throws.TypeOf<IncompleteModelException>());
 
             var feature = new Feature();
 
@@ -51,7 +52,7 @@ public void VerifyComputeFeatureChained()
 
             ((IContainedRelationship)nonFeatureChaining).OwningRelatedElement = nonFeatureOwner;
 
-            Assert.That(nonFeatureChaining.ComputeFeatureChained(), Is.Null);
+            Assert.That(nonFeatureChaining.ComputeFeatureChained, Throws.TypeOf<IncompleteModelException>());
         }
     }
 }

SysML2.NET.Tests/Extend/FeatureInvertingExtensionsTestFixture.cs

@@ -1,20 +1,20 @@
 // -------------------------------------------------------------------------------------------------
 // <copyright file="FeatureInvertingExtensionsTestFixture.cs" company="Starion Group S.A.">
-//
-//   Copyright 2022-2026 Starion Group S.A.
-//
+// 
+//   Copyright (C) 2022-2026 Starion Group S.A.
+// 
 //   Licensed under the Apache License, Version 2.0 (the "License");
 //   you may not use this file except in compliance with the License.
 //   You may obtain a copy of the License at
-//
+// 
 //        http://www.apache.org/licenses/LICENSE-2.0
-//
+// 
 //    Unless required by applicable law or agreed to in writing, software
 //    distributed under the License is distributed on an "AS IS" BASIS,
 //    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 //    See the License for the specific language governing permissions and
 //    limitations under the License.
-//
+// 
 // </copyright>
 // ------------------------------------------------------------------------------------------------
 
@@ -44,8 +44,19 @@ public void VerifyComputeOwningFeature()
 
             ((IContainedRelationship)featureInverting).OwningRelatedElement = feature;
 
+            // owningFeature subsets featureInverted, so the owner must play that role to surface.
+            Assert.That(featureInverting.ComputeOwningFeature(), Is.Null);
+
+            featureInverting.FeatureInverted = feature;
+
             Assert.That(featureInverting.ComputeOwningFeature(), Is.SameAs(feature));
 
+            featureInverting.FeatureInverted = new Feature();
+
+            Assert.That(featureInverting.ComputeOwningFeature(), Is.Null);
+
+            featureInverting.FeatureInverted = feature;
+
             var nonFeatureOwner = new Namespace();
             var nonFeatureInverting = new FeatureInverting();
 

SysML2.NET.Tests/Extend/FeatureTypingExtensionsTestFixture.cs

@@ -1,20 +1,20 @@
 // -------------------------------------------------------------------------------------------------
 // <copyright file="FeatureTypingExtensionsTestFixture.cs" company="Starion Group S.A.">
-//
-//   Copyright 2022-2026 Starion Group S.A.
-//
+// 
+//   Copyright (C) 2022-2026 Starion Group S.A.
+// 
 //   Licensed under the Apache License, Version 2.0 (the "License");
 //   you may not use this file except in compliance with the License.
 //   You may obtain a copy of the License at
-//
+// 
 //        http://www.apache.org/licenses/LICENSE-2.0
-//
+// 
 //    Unless required by applicable law or agreed to in writing, software
 //    distributed under the License is distributed on an "AS IS" BASIS,
 //    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 //    See the License for the specific language governing permissions and
 //    limitations under the License.
-//
+// 
 // </copyright>
 // ------------------------------------------------------------------------------------------------
 
@@ -44,8 +44,19 @@ public void VerifyComputeOwningFeature()
 
             ((IContainedRelationship)featureTyping).OwningRelatedElement = feature;
 
+            // owningFeature subsets typedFeature, so the owner must play that role to surface.
+            Assert.That(featureTyping.ComputeOwningFeature(), Is.Null);
+
+            featureTyping.TypedFeature = feature;
+
             Assert.That(featureTyping.ComputeOwningFeature(), Is.SameAs(feature));
 
+            featureTyping.TypedFeature = new Feature();
+
+            Assert.That(featureTyping.ComputeOwningFeature(), Is.Null);
+
+            featureTyping.TypedFeature = feature;
+
             var namespaceOwner = new Namespace();
             var nonFeatureFeatureTyping = new FeatureTyping();
 

SysML2.NET.Tests/Extend/FlowExtensionsTestFixture.cs

@@ -1,20 +1,20 @@
 // -------------------------------------------------------------------------------------------------
 // <copyright file="FlowExtensionsTestFixture.cs" company="Starion Group S.A.">
-//
-//   Copyright 2022-2026 Starion Group S.A.
-//
+// 
+//   Copyright (C) 2022-2026 Starion Group S.A.
+// 
 //   Licensed under the Apache License, Version 2.0 (the "License");
 //   you may not use this file except in compliance with the License.
 //   You may obtain a copy of the License at
-//
+// 
 //        http://www.apache.org/licenses/LICENSE-2.0
-//
+// 
 //    Unless required by applicable law or agreed to in writing, software
 //    distributed under the License is distributed on an "AS IS" BASIS,
 //    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 //    See the License for the specific language governing permissions and
 //    limitations under the License.
-//
+// 
 // </copyright>
 // ------------------------------------------------------------------------------------------------
 
@@ -211,7 +211,7 @@ public void VerifyComputeSourceOutputFeature()
 
             Assert.That(flow.ComputeSourceOutputFeature(), Is.SameAs(innerFeatureA));
 
-            // Empty first end + non-empty second end → second end's first feature returned.
+            // Empty first end + non-empty second end → null; KerML §8.3.4.9.2 scopes the derivation to end 1.
             var flow2 = new Flow();
 
             var emptyEnd = new Feature { IsEnd = true };
@@ -226,7 +226,7 @@ public void VerifyComputeSourceOutputFeature()
             var secondEndInnerMembership = new FeatureMembership();
             nonEmptyEnd.AssignOwnership(secondEndInnerMembership, secondEndFeature);
 
-            Assert.That(flow2.ComputeSourceOutputFeature(), Is.SameAs(secondEndFeature));
+            Assert.That(flow2.ComputeSourceOutputFeature(), Is.Null);
         }
 
         [Test]