[1998] Add Implicit TypeFeaturing

CHANGELOG.adoc

@@ -39,6 +39,7 @@ The property `SysONTestsProperties#ELASTICSEARCH` has been removed, tests that r
 For example `ViewUsage` elements are no longer rendered in _parts_ compartments.
 - https://github.com/eclipse-syson/syson/issues/1981[#1981] [export] Fix an error during textual export where `Expose` elements with apostrophes in their name were not properly escaped.
 - https://github.com/eclipse-syson/syson/issues/1983[#1983] [metamodel] `reqId` and `declaredShortName` properties of `RequirementDefinition` and `RequirementUsage` are now synchronized, as required by the SysMLv2 specification.
+- https://github.com/eclipse-syson/syson/issues/1998[#1998] Missing implicit TypeFeaturing.
 
 === Improvements
 

backend/metamodel/syson-sysml-metamodel/src/main/java/org/eclipse/syson/sysml/impl/FeatureImpl.java

@@ -46,6 +46,7 @@
 import org.eclipse.syson.sysml.Redefinition;
 import org.eclipse.syson.sysml.ReferenceSubsetting;
 import org.eclipse.syson.sysml.Subsetting;
+import org.eclipse.syson.sysml.SysmlFactory;
 import org.eclipse.syson.sysml.SysmlPackage;
 import org.eclipse.syson.sysml.Type;
 import org.eclipse.syson.sysml.TypeFeaturing;
@@ -462,6 +463,13 @@ public EList<Type> getFeaturingType() {
         if (!chainingFeature.isEmpty()) {
             featuringTypes.addAll(chainingFeature.get(0).getFeaturingType());
         }
+
+        // Add implicit featuring type
+        Type implicitType = this.computeImplicitFeaturingType();
+        if (implicitType != null) {
+            featuringTypes.add(implicitType);
+        }
+
         return new EcoreEList.UnmodifiableEList<>(this, SysmlPackage.eINSTANCE.getFeature_FeaturingType(), featuringTypes.size(), featuringTypes.toArray());
     }
 
@@ -1539,4 +1547,35 @@ private Collection<Feature> collectTypingFeatures() {
         }
         return featureCollector;
     }
+
+    /**
+     * @generated NOT
+     */
+    private Type computeImplicitFeaturingType() {
+        Type owningType = this.getOwningType();
+        Type implicitType = null;
+        if (owningType != null) {
+
+            if (!this.isIsVariable()) {
+                // KerML 7.3.2.6 “Feature Membership” – “A feature that is declared within the body of a type … automatically has that type as a featuring type.”
+                implicitType = owningType;
+            } else {
+                // KerML 8.4.4.3
+                // Class (or any Type that directly or indirectly specializes Occurrence) may have ownedFeatures with
+                // isVariable = true. The checkFeatureFeatureMembershipTypeFeaturing constraint requires that such
+                //  variable Features are featured by the snapshots of their owningType.
+                implicitType = SysmlFactory.eINSTANCE.createFeature();
+                implicitType.setDeclaredName(owningType.getDeclaredName() + "-SNAPSHOT");
+
+                // This virtual type should at some point redefine Occurrences::Occurrence::snapshots
+
+                TypeFeaturing typeFeaturing = SysmlFactory.eINSTANCE.createTypeFeaturing();
+                typeFeaturing.setFeaturingType(owningType);
+                typeFeaturing.setFeatureOfType((Feature) implicitType);
+                implicitType.getOwnedRelationship().add(typeFeaturing);
+            }
+
+        }
+        return implicitType;
+    }
 } // FeatureImpl

backend/metamodel/syson-sysml-metamodel/src/test/java/org/eclipse/syson/sysml/impl/FeatureImplTest.java

@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2024 Obeo.
+ * Copyright (c) 2024, 2026 Obeo.
  * This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v2.0
  * which accompanies this distribution, and is available at
@@ -12,12 +12,16 @@
  *******************************************************************************/
 package org.eclipse.syson.sysml.impl;
 
+import static org.assertj.core.api.Assertions.assertThat;
 import static org.junit.Assert.assertNull;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 
 import org.eclipse.syson.sysml.Feature;
+import org.eclipse.syson.sysml.ItemDefinition;
+import org.eclipse.syson.sysml.ItemUsage;
 import org.eclipse.syson.sysml.util.ModelBuilder;
 import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.DisplayName;
 import org.junit.jupiter.api.Test;
 
 /**
@@ -59,4 +63,21 @@ public void testNames() {
         assertEquals("f", f2.effectiveShortName());
     }
 
+
+    @Test
+    @DisplayName("GIVEN a non variable feature in a Type, WHEN computing it's featuring types, THEN the owning type is returned")
+    public void checkImplicitFeaturingTypeNoVariableFeature() {
+        var itemDef = this.builder.createWithName(ItemDefinition.class, "ItemDef");
+        ItemUsage itemUsage = this.builder.createInWithName(ItemUsage.class, itemDef, "ItemUsage");
+        assertThat(itemUsage.getFeaturingType()).hasSize(1).allMatch(type -> type == itemDef);
+    }
+
+    @Test
+    @DisplayName("GIVEN a variable feature in a Type, WHEN computing it's featuring types, THEN the owning type is returned")
+    public void checkImplicitFeaturingTypeVariableFeature() {
+        var itemDef = this.builder.createWithName(ItemDefinition.class, "ItemDef");
+        ItemUsage itemUsage = this.builder.createInWithName(ItemUsage.class, itemDef, "ItemUsage");
+        itemUsage.setIsVariable(true);
+        assertThat(itemUsage.getFeaturingType()).hasSize(1).allMatch(type -> "ItemDef-SNAPSHOT".equals(type.getName()));
+    }
 }

doc/content/modules/user-manual/pages/release-notes/2026.3.0.adoc

@@ -65,6 +65,14 @@ part system {
 
 ** `Req Id` and `Declared Short Name` properties of `RequirementDefinition` and `RequirementUsage` are now synchronized, as required by the SysMLv2 specification.
 
+* In _Validation_ view:
+
+** Improve the computation to _featuringType_ on `Feature` to avoid getting the following validation error:
++
+```
+If a Feature is owned via a FeatureMembership, then it must have a featuringType for which the operation isFeaturingType returns true. (checkFeatureFeatureMembershipTypeFeaturing constraint on Feature is not respected for Test::MyItemDef::myFeature)
+````
+
 == Improvements
 
 * In diagrams: