fix: tolerate an unresolvable grammar in export model generation

com.avaloq.tools.ddk.xtext.export.test/src/com/avaloq/tools/ddk/xtext/export/generator/ExportGeneratorXTest.java

@@ -0,0 +1,99 @@
+/*******************************************************************************
+ * Copyright (c) 2026 Avaloq Group AG and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *     Avaloq Group AG - initial API and implementation
+ *******************************************************************************/
+package com.avaloq.tools.ddk.xtext.export.generator;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNull;
+
+import org.eclipse.emf.common.util.URI;
+import org.eclipse.emf.ecore.InternalEObject;
+import org.eclipse.emf.ecore.resource.Resource;
+import org.eclipse.emf.ecore.resource.impl.ResourceImpl;
+import org.eclipse.emf.ecore.resource.impl.ResourceSetImpl;
+import org.eclipse.xtext.Grammar;
+import org.eclipse.xtext.XtextFactory;
+import org.junit.jupiter.api.Test;
+
+import com.avaloq.tools.ddk.xtext.export.export.ExportFactory;
+import com.avaloq.tools.ddk.xtext.export.export.ExportModel;
+import com.avaloq.tools.ddk.xtext.test.export.util.ExportTestUtil;
+import com.avaloq.tools.ddk.xtext.test.jupiter.AbstractXtextTest;
+
+
+/**
+ * Regression tests for URI-based package derivation in {@link ExportGeneratorX}.
+ */
+@SuppressWarnings("nls")
+public class ExportGeneratorXTest extends AbstractXtextTest {
+
+  private static final String DERIVED_PACKAGE_PROVIDER = "com.avaloq.naming.fooExportedNamesProvider";
+  private static final String PROJECT_FALLBACK_PROVIDER = "MyProject.naming.fooExportedNamesProvider";
+  private static final String DEFAULT_FALLBACK_PROVIDER = "generated.naming.fooExportedNamesProvider";
+  private static final String NO_SIBLING_URI = "platform:/resource/TEST/NoSibling.export";
+
+  private final ExportGeneratorX exportGeneratorX = getXtextTestUtil().get(ExportGeneratorX.class);
+
+  @Override
+  protected ExportTestUtil getXtextTestUtil() {
+    return ExportTestUtil.getInstance();
+  }
+
+  @Override
+  protected String getTestSourceFileName() {
+    return null; // all tests fabricate synthetic resource URIs
+  }
+
+  @Test
+  public void testNestedSourceFolderUrisKeepDerivedPackage() {
+    assertEquals(DERIVED_PACKAGE_PROVIDER, exportedNamesProviderFor("platform:/resource/MyProject/src/com/avaloq/foo.export"));
+    assertEquals(DERIVED_PACKAGE_PROVIDER, exportedNamesProviderFor("platform:/resource/MyProject/src-gen/com/avaloq/foo.export"));
+    assertEquals("main.java.com.avaloq.naming.fooExportedNamesProvider", exportedNamesProviderFor("platform:/resource/MyProject/src/main/java/com/avaloq/foo.export"));
+  }
+
+  @Test
+  public void testShortUrisFallBackToValidPackage() {
+    assertEquals(PROJECT_FALLBACK_PROVIDER, exportedNamesProviderFor("platform:/resource/MyProject/foo.export"));
+    assertEquals(PROJECT_FALLBACK_PROVIDER, exportedNamesProviderFor("platform:/resource/MyProject/src/foo.export"));
+    assertEquals(DEFAULT_FALLBACK_PROVIDER, exportedNamesProviderFor("platform:/resource/1My-Project/foo.export"));
+  }
+
+  @Test
+  public void testSingleSegmentUriFallsBackToDefaultPackage() {
+    assertEquals(DEFAULT_FALLBACK_PROVIDER, exportedNamesProviderFor("foo.export"));
+  }
+
+  @Test
+  public void testGetGrammarReturnsNullWithoutResolvableGrammar() {
+    final ExportModel detached = ExportFactory.eINSTANCE.createExportModel();
+    assertNull(exportGeneratorX.getGrammar(detached), "model without a resource");
+
+    final ExportModel withoutResourceSet = ExportFactory.eINSTANCE.createExportModel();
+    new ResourceImpl(URI.createURI(NO_SIBLING_URI)).getContents().add(withoutResourceSet);
+    assertNull(exportGeneratorX.getGrammar(withoutResourceSet), "resource without a resource set");
+
+    final ExportModel withoutSibling = ExportFactory.eINSTANCE.createExportModel();
+    final Resource resource = new ResourceSetImpl().createResource(URI.createURI(NO_SIBLING_URI));
+    resource.getContents().add(withoutSibling);
+    assertNull(exportGeneratorX.getGrammar(withoutSibling), "missing sibling grammar must not throw");
+
+    final Grammar proxy = XtextFactory.eINSTANCE.createGrammar();
+    ((InternalEObject) proxy).eSetProxyURI(URI.createURI("platform:/resource/TEST/Unresolved.xtext#/"));
+    withoutSibling.setTargetGrammar(proxy);
+    assertNull(exportGeneratorX.getGrammar(withoutSibling), "unresolved targetGrammar proxy");
+  }
+
+  private String exportedNamesProviderFor(final String uri) {
+    final Resource resource = new ResourceImpl(URI.createURI(uri));
+    final ExportModel model = ExportFactory.eINSTANCE.createExportModel();
+    resource.getContents().add(model);
+    return exportGeneratorX.getExportedNamesProvider(model);
+  }
+}

com.avaloq.tools.ddk.xtext.export.test/src/com/avaloq/tools/ddk/xtext/test/export/ExportTestSuite.java

@@ -13,6 +13,7 @@
 import org.junit.platform.suite.api.SelectClasses;
 import org.junit.platform.suite.api.Suite;
 
+import com.avaloq.tools.ddk.xtext.export.generator.ExportGeneratorXTest;
 import com.avaloq.tools.ddk.xtext.export.exporting.ExportExportingTest;
 import com.avaloq.tools.ddk.xtext.export.formatting.ExportFormattingTest;
 import com.avaloq.tools.ddk.xtext.export.scoping.ExportScopingTest;
@@ -24,6 +25,6 @@
  * Empty class serving only as holder for JUnit 5 suite annotations.
  */
 @Suite
-@SelectClasses({ExportFormattingTest.class, ExportValidationTest.class, ExportValidationOkTest.class, ExportScopingTest.class, ExportExportingTest.class})
+@SelectClasses({ExportFormattingTest.class, ExportValidationTest.class, ExportValidationOkTest.class, ExportScopingTest.class, ExportExportingTest.class, ExportGeneratorXTest.class})
 public class ExportTestSuite {
 }

com.avaloq.tools.ddk.xtext.export/src/com/avaloq/tools/ddk/xtext/export/generator/ExportGeneratorX.xtend

@@ -24,6 +24,7 @@ import com.google.inject.Inject
 import java.util.Collection
 import java.util.List
 import java.util.Map
+import javax.lang.model.SourceVersion
 import org.eclipse.emf.ecore.EAttribute
 import org.eclipse.emf.ecore.EClass
 import org.eclipse.emf.ecore.EClassifier
@@ -42,22 +43,35 @@ class ExportGeneratorX {
   }
 
   def Grammar getGrammar(ExportModel model) {
-    val uri = model.eResource.URI
     // Grammar should be set correctly for export extensions, not yet for normal export sources
-    if(model.targetGrammar !== null) {
+    if (model.targetGrammar !== null && !model.targetGrammar.eIsProxy) {
       return model.targetGrammar;
     }
-    val grammarResource = model.eResource.resourceSet.getResource(uri.trimSegments(1).appendSegment(uri.trimFileExtension.lastSegment + '.xtext'), true)
-    return grammarResource?.contents.head as Grammar
+    val resource = model.eResource
+    if (resource?.resourceSet === null) {
+      return null
+    }
+    val uri = resource.URI
+    try {
+      val grammarResource = resource.resourceSet.getResource(uri.trimSegments(1).appendSegment(uri.trimFileExtension.lastSegment + '.xtext'), true)
+      return grammarResource?.contents.head as Grammar
+    } catch (RuntimeException e) {
+      // no resolvable sibling grammar; all generators tolerate a null grammar
+      return null
+    }
   }
 
   def List<String> getPrefix(URI uri) {
     // TODO we still need to add a package to the models. Extension models already have a name in contrast to cases above
-    if (uri.segmentsList().size > 3) {
-      return uri.segmentsList().subList(3, uri.segmentCount() - 1);      
-    } else {
-      return uri.segmentsList().subList(uri.segmentCount() - 2, uri.segmentCount() - 1);
+    val segments = uri.segmentsList
+    if (segments.size > 4) {
+      return segments.subList(3, segments.size - 1)
+    }
+    // shorter shapes have no package segments: fall back to a valid package name
+    if (segments.size > 2 && SourceVersion.isName(segments.get(1))) {
+      return #[segments.get(1)]
     }
+    return #['generated']
   }
 
   def String getExportedNamesProvider(ExportModel model) {

com.avaloq.tools.ddk.xtext.expression/src/com/avaloq/tools/ddk/xtext/expression/generator/GeneratorUtil.java

@@ -55,7 +55,9 @@ protected GeneratorUtil() {
    */
   public static Set<EClass> allInstantiatedTypes(final Grammar grammar) {
     Set<EClass> result = Sets.newLinkedHashSet();
-    collectInstantiatedTypes(grammar, result);
+    if (grammar != null) { // no grammar -> no parser-instantiated subtypes
+      collectInstantiatedTypes(grammar, result);
+    }
     return result;
   }