[2143] Replace Path with String in library loading configuration

CHANGELOG.adoc

@@ -12,10 +12,10 @@
 - [cleanup] The definition of the tools specific to the requirements table has been moved to the backend.
 As a result, the following GraphQL mutations have been removed `exposeRequirements` and `createRequirement`.
 - [test] Reduce our call to `DiagramNavigator#nodeWithTargetObjectLabel` which has been deprecated for removal.
-+ The API of `ToolTester#invokeTool` and `NodeCreationTestsService#createNode` has been updated accordingly to take a `targetObjectId` instead of a `label`.
+The API of `ToolTester#invokeTool` and `NodeCreationTestsService#createNode` has been updated accordingly to take a `targetObjectId` instead of a `label`.
 - https://github.com/eclipse-syson/syson/issues/2045[#2045] [diagrams] The service `ViewNodeService#revealCompartment` has been changed to reveal a compartment only when it is needed.
-+ Only reveal a compartment of a node when none of the revealed compartment can display the `targetElement`.
-+ If many compartment candidates exist, choose the first free form compartment.
+Only reveal a compartment of a node when none of the revealed compartment can display the `targetElement`.
+If many compartment candidates exist, choose the first free form compartment.
 - [services] As part of the migration to the new diagram service architecture, the following methods have been moved out of `ViewNodeService` (which as been deleted):
 +
 ** `List<Element> getExposedElements(Element self, EClass domainType, List<Object> ancestors, IEditingContext editingContext, DiagramContext diagramContext)` to `DiagramQueryAQLService.getExposedElements(Element self, EClass domainType, List<Object> ancestors, IEditingContext editingContext, DiagramContext diagramContext)`
@@ -34,6 +34,8 @@ As a result, the following GraphQL mutations have been removed `exposeRequiremen
 ** `org.eclipse.syson.diagram.common.view.services.RevealCompartmentSwitch` to `org.eclipse.syson.diagram.services.utils.RevealCompartmentSwitch`
 +
 Also, a new helper method `DiagramQueryAQLService.isNotAncestorOf(...)` has been added to support edge preconditions previously written as `aql:not graphicalEdgeSource.isAncestorOf(graphicalEdgeTarget, cache)`.
+- https://github.com/eclipse-syson/syson/issues/2143[#2143] [configuration] The `relativePathToDirectoryContainingLibraryFiles` field in `SysONLibraryLoadingDefinition` now expects a `String` instead of a `java.nio.file.Path`.
+This change ensures compatibility with classpath resource resolution, which requires forward slashes (`/`) as path separators.
 
 === Dependency update
 
@@ -53,6 +55,7 @@ Also, a new helper method `DiagramQueryAQLService.isNotAncestorOf(...)` has been
 
 - https://github.com/eclipse-syson/syson/issues/2045[#2045] [diagrams] In Interconnection View diagrams, fix an issue where the `parts` compartment of a `PartDefinition` graphical node was incorrectly revealed when creating a `PartUsage` from the `PartDefinition` graphical node, even if the `interconnection` compartment was already visible.
 - https://github.com/eclipse-syson/syson/issues/2094[#2094] [libraries] Ensure library documents are read-only.
+- https://github.com/eclipse-syson/syson/issues/2143[#2143] [configuration] Fixed classpath resource resolution on Windows by enforcing forward slashes (`/`) in library paths.
 
 === Improvements
 

backend/application/syson-application-configuration/src/main/java/org/eclipse/syson/application/configuration/SysONDefaultLibrariesConfiguration.java

@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2024, 2025 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
@@ -12,7 +12,6 @@
  *******************************************************************************/
 package org.eclipse.syson.application.configuration;
 
-import java.nio.file.Paths;
 import java.time.Duration;
 import java.time.Instant;
 import java.util.Collections;
@@ -47,14 +46,14 @@ public class SysONDefaultLibrariesConfiguration {
     public static final SysONLibraryLoadingDefinition KERML = new SysONLibraryLoadingDefinition(
             "KerML Standard Library",
             ElementUtil.KERML_LIBRARY_SCHEME,
-            Paths.get("kerml.libraries"),
+            "kerml.libraries",
             Collections.singletonList(JsonResourceFactoryImpl.EXTENSION),
             new JSONResourceFactory()::createResource);
 
     public static final SysONLibraryLoadingDefinition SYSML = new SysONLibraryLoadingDefinition(
             "SysML Standard Library",
             ElementUtil.SYSML_LIBRARY_SCHEME,
-            Paths.get("sysml.libraries"),
+            "sysml.libraries",
             Collections.singletonList(JsonResourceFactoryImpl.EXTENSION),
             new JSONResourceFactory()::createResource);
 

backend/application/syson-application-configuration/src/main/java/org/eclipse/syson/application/libraries/SysONLibraryLoader.java

@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2025 Obeo.
+ * Copyright (c) 2025, 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
@@ -132,7 +132,7 @@ public List<ClassPathResource> findAllLibraryResourcesFromApplicationClasspath(f
         final List<ClassPathResource> allResourcesForLibraryLoadingDefinition = new ArrayList<>();
         final PathMatchingResourcePatternResolver resolver = new PathMatchingResourcePatternResolver();
         for (final String fileExtension : definition.fileExtensions()) {
-            final String locationPattern = ResourcePatternResolver.CLASSPATH_ALL_URL_PREFIX + definition.relativePathToDirectoryContainingLibraryFiles().toString() + "/*." + fileExtension;
+            final String locationPattern = ResourcePatternResolver.CLASSPATH_ALL_URL_PREFIX + definition.relativePathToDirectoryContainingLibraryFiles() + "/*." + fileExtension;
 
             final List<org.springframework.core.io.Resource> resources = new ArrayList<>();
             try {
@@ -141,7 +141,7 @@ public List<ClassPathResource> findAllLibraryResourcesFromApplicationClasspath(f
                 LOGGER.error("There was an unexpected issue while attempting to retrieve %s resources at location: %s".formatted(definition.familyName(), locationPattern), ioException);
             }
 
-            resources.stream().map(resource -> new ClassPathResource(definition.relativePathToDirectoryContainingLibraryFiles().resolve(resource.getFilename()).toString()))
+            resources.stream().map(resource -> new ClassPathResource(definition.relativePathToDirectoryContainingLibraryFiles() + "/" + resource.getFilename()))
                     .forEach(allResourcesForLibraryLoadingDefinition::add);
         }
 

backend/application/syson-application-configuration/src/main/java/org/eclipse/syson/application/libraries/SysONLibraryLoadingDefinition.java

@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2025 Obeo.
+ * Copyright (c) 2025, 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
@@ -12,7 +12,6 @@
  *******************************************************************************/
 package org.eclipse.syson.application.libraries;
 
-import java.nio.file.Path;
 import java.util.List;
 import java.util.Objects;
 import java.util.function.Function;
@@ -24,7 +23,9 @@
 /**
  * Defines how to identify, retrieve and load the different files constituting a SysON library.
  *
- * Note that the resources must be in the classpath of the application.
+ * The resources must be in the classpath of the application.
+ * The {@code relativePathToDirectoryContainingLibraryFiles} must use forward slashes ("/") as separators,
+ * as it is intended to be used in the classpath (e.g., JAR files or classpath directories).
  *
  * @author flatombe
  * @see SysONDefaultLibrariesConfiguration#KERML
@@ -33,7 +34,7 @@
 public record SysONLibraryLoadingDefinition(
         String familyName,
         String scheme,
-        Path relativePathToDirectoryContainingLibraryFiles,
+        String relativePathToDirectoryContainingLibraryFiles,
         List<String> fileExtensions,
         Function<URI, Resource> resourceLoadingBehavior) {
 
@@ -45,9 +46,7 @@ public record SysONLibraryLoadingDefinition(
      * @param scheme
      *            the (non-{@code null}) scheme to use for the EMF {@link URI}s used to load resources of this library.
      * @param relativePathToDirectoryContainingLibraryFiles
-     *            the (non-{@code null}) relative {@link Path} to the <b>directory</b> containing the library files. If
-     *            set to {@code foo/bar} then the library files are expected to be in directory
-     *            {@code src/main/resources/foo/bar}.
+     *            the (non-{@code null}) relative path (using forward slashes "/") to the <b>directory</b> containing the library files in the classpath.
      * @param fileExtensions
      *            the (non-{@code null}) {@link List} of file extensions to look for in
      *            {@code relativePathToDirectoryContainingLibraryFiles}.
@@ -61,11 +60,15 @@ public record SysONLibraryLoadingDefinition(
         Objects.requireNonNull(fileExtensions);
         Objects.requireNonNull(resourceLoadingBehavior);
 
-        if (relativePathToDirectoryContainingLibraryFiles.isAbsolute()) {
-            throw new IllegalArgumentException("Path '%s' is absolute, but a relative one was expected.".formatted(relativePathToDirectoryContainingLibraryFiles.toString()));
+        if (relativePathToDirectoryContainingLibraryFiles.startsWith("/")) {
+            throw new IllegalArgumentException("Path '%s' is absolute, but a relative one was expected.".formatted(relativePathToDirectoryContainingLibraryFiles));
         }
-        if (relativePathToDirectoryContainingLibraryFiles.toFile().exists() && !relativePathToDirectoryContainingLibraryFiles.toFile().isDirectory()) {
-            throw new IllegalArgumentException("Path '%s' exists but is not a directory.".formatted(relativePathToDirectoryContainingLibraryFiles.toString()));
+
+        // Validate that the path does not contain Windows-style separators
+        if (relativePathToDirectoryContainingLibraryFiles.contains("\\")) {
+            throw new IllegalArgumentException(
+                    "Path '%s' contains Windows-style separators ('\\'). Only forward slashes ('/') are allowed for classpath resources.".formatted(relativePathToDirectoryContainingLibraryFiles)
+            );
         }
     }
 

backend/application/syson-application-configuration/src/test/java/org/eclipse/syson/application/configuration/SysONLibraryLoadingDefinitionTest.java

@@ -0,0 +1,85 @@
+/*******************************************************************************
+ * Copyright (c) 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
+ * https://www.eclipse.org/legal/epl-2.0/
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors:
+ *     Obeo - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.syson.application.configuration;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.mockito.Mockito.mock;
+
+import java.util.List;
+import java.util.function.Function;
+
+import org.eclipse.emf.common.util.URI;
+import org.eclipse.emf.ecore.resource.Resource;
+import org.eclipse.syson.application.libraries.SysONLibraryLoadingDefinition;
+import org.junit.jupiter.api.Test;
+
+/**
+ * Test about the library loading definition.
+ *
+ * @author frouene
+ */
+public class SysONLibraryLoadingDefinitionTest {
+
+    private static final String VALID_FAMILY_NAME = "TestLibrary";
+    private static final String VALID_SCHEME = "test";
+    private static final String VALID_RELATIVE_PATH = "name/library";
+    private static final List<String> VALID_EXTENSIONS = List.of("json", "xml");
+    private static final Function<URI, Resource> VALID_LOADING_BEHAVIOR = mock(Function.class);
+
+    @Test
+    void testValidDefinition() {
+        SysONLibraryLoadingDefinition definition = new SysONLibraryLoadingDefinition(
+                VALID_FAMILY_NAME,
+                VALID_SCHEME,
+                VALID_RELATIVE_PATH,
+                VALID_EXTENSIONS,
+                VALID_LOADING_BEHAVIOR
+        );
+
+        assertNotNull(definition);
+        assertEquals(VALID_FAMILY_NAME, definition.familyName());
+        assertEquals(VALID_SCHEME, definition.scheme());
+        assertEquals(VALID_RELATIVE_PATH, definition.relativePathToDirectoryContainingLibraryFiles());
+        assertEquals(VALID_EXTENSIONS, definition.fileExtensions());
+        assertEquals(VALID_LOADING_BEHAVIOR, definition.resourceLoadingBehavior());
+    }
+
+    @Test
+    void testAbsolutePath() {
+        assertThrows(IllegalArgumentException.class, () ->
+                new SysONLibraryLoadingDefinition(
+                        VALID_FAMILY_NAME,
+                        VALID_SCHEME,
+                        "/name/library",
+                        VALID_EXTENSIONS,
+                        VALID_LOADING_BEHAVIOR
+                )
+        );
+    }
+
+    @Test
+    void testWindowsSeparators() {
+        assertThrows(IllegalArgumentException.class, () ->
+                new SysONLibraryLoadingDefinition(
+                        VALID_FAMILY_NAME,
+                        VALID_SCHEME,
+                        "name\\library",
+                        VALID_EXTENSIONS,
+                        VALID_LOADING_BEHAVIOR
+                )
+        );
+    }
+
+}