Fix ExtensionException in OSGi environment for global extension (#2079)

Implement the same resource logic with ContextClassLoader as JUnit
platform.

Fixes #2076

Author: AndreasTu

docs/release_notes.adoc

@@ -3,7 +3,12 @@
 
 include::include.adoc[]
 
-== 2.4 (tbd)
+== 2.4-M6 (tbd)
+
+=== Misc
+
+* Fix ExtensionException in OSGi environment for global extension spockIssue:2076[]
+** This issue was introduced with spockPull:1995[]
 
 == 2.4-M5 (2025-01-07)
 

spock-core/src/main/java/org/spockframework/runtime/ExtensionClassesLoader.java

@@ -56,7 +56,7 @@ public <T> List<Class<? extends T>> loadClasses(String descriptorPath, Class<T>
 
   private Collection<URL> locateDescriptors(String descriptorPath) {
     try {
-      return ReflectionUtil.getResourcesFromClassLoaders(descriptorPath);
+      return ReflectionUtil.getResourcesFromClassLoader(descriptorPath);
     } catch (Exception e) {
       throw new ExtensionException("Failed to locate extension descriptors", e);
     }

spock-core/src/main/java/org/spockframework/util/ReflectionUtil.java

@@ -86,30 +86,24 @@ public static Class<?> loadClass(String className) throws ClassNotFoundException
   }
 
   /**
-   * Returns the resources from the following classloaders:
-   * <ul>
-   * <li>Spock {@link ClassLoader}</li>
-   * <li>{@code Thread.currentThread().getContextClassLoader()}</li>
-   * </ul>
+   * Returns the resources from the {@code Thread.currentThread().getContextClassLoader()}.
    *
    * @param resourcePath the path of the resource
    * @return the list of resources
    * @throws IOException if the resources can't be loaded
    */
-  public static Collection<URL> getResourcesFromClassLoaders(String resourcePath) throws IOException {
-    ClassLoader spockClassLoader = ReflectionUtil.class.getClassLoader();
-    // We need to use a sorted Set here, to filter out duplicates, if the ContextClassLoader can also reach the Spock classloader
-    TreeSet<URL> set = new TreeSet<>(Comparator.comparing(URL::toString));
-    set.addAll(Collections.list(spockClassLoader.getResources(resourcePath)));
+  public static Collection<URL> getResourcesFromClassLoader(String resourcePath) throws IOException {
     try {
-      //Also resolve resources via ContextClassLoader to better support for runtimes like OSGi
+      //Resolve resources via ContextClassLoader to better support for runtimes like OSGi
+      //Issue #2076: But du not use ContextClassLoader and the Spock ClassLoader and merge the results, because this fails for bundle resources
       ClassLoader contextClassLoader = Thread.currentThread().getContextClassLoader();
-      if (contextClassLoader != null && spockClassLoader != contextClassLoader) {
-        set.addAll(Collections.list(contextClassLoader.getResources(resourcePath)));
+      if (contextClassLoader != null) {
+        return Collections.list(contextClassLoader.getResources(resourcePath));
       }
     } catch (SecurityException ignored) {
     }
-    return set;
+    ClassLoader spockClassLoader = ReflectionUtil.class.getClassLoader();
+    return Collections.list(spockClassLoader.getResources(resourcePath));
   }
 
   public static boolean isClassAvailable(String className) {

spock-specs/src/test/groovy/org/spockframework/util/ReflectionUtilSpec.groovy

@@ -58,13 +58,14 @@ class ReflectionUtilSpec extends Specification {
     Thread.currentThread().setContextClassLoader(oldLoader)
   }
 
-  def "getResourcesFromClassLoaders"() {
+  def getResourcesFromClassLoader() {
     when:
-    def res = ReflectionUtil.getResourcesFromClassLoaders(JarFile.MANIFEST_NAME)
+    def res = ReflectionUtil.getResourcesFromClassLoader(JarFile.MANIFEST_NAME)
     then:
     res.size() >= 1
   }
 
+  @Issue("https://github.com/spockframework/spock/issues/2076")
   def "getResourcesFromClassLoaders - ContextClassLoader"() {
     given:
     def oldLoader = Thread.currentThread().getContextClassLoader()
@@ -74,23 +75,18 @@ class ReflectionUtilSpec extends Specification {
       @Override
       Enumeration<URL> getResources(String name) throws IOException {
         if (name == resPath) {
-          def url = new URL("file:/" + resPath)
-          return new Vector([
-            //Check that we filter out duplicates
-            url,
-            url
-          ]).elements()
+          return new Vector([new URL("file:/" + resPath)]).elements()
         }
         return super.getResources(name)
       }
     }
 
     expect:
-    ReflectionUtil.getResourcesFromClassLoaders(resPath).isEmpty()
+    ReflectionUtil.getResourcesFromClassLoader(resPath).isEmpty()
 
     when:
     Thread.currentThread().setContextClassLoader(resCl)
-    def res = ReflectionUtil.getResourcesFromClassLoaders(resPath)
+    def res = ReflectionUtil.getResourcesFromClassLoader(resPath)
     then:
     res.size() == 1
     res[0].toString().contains(resPath)
@@ -99,6 +95,21 @@ class ReflectionUtilSpec extends Specification {
     Thread.currentThread().setContextClassLoader(oldLoader)
   }
 
+  @Issue("https://github.com/spockframework/spock/issues/2076")
+  def "getResourcesFromClassLoaders - ContextClassLoader == null"() {
+    given:
+    def oldLoader = Thread.currentThread().getContextClassLoader()
+
+    when:
+    Thread.currentThread().setContextClassLoader(null)
+    def res = ReflectionUtil.getResourcesFromClassLoader(JarFile.MANIFEST_NAME)
+    then:
+    res.size() >= 1
+
+    cleanup:
+    Thread.currentThread().setContextClassLoader(oldLoader)
+  }
+
   def "check if class exists"() {
     expect:
     ReflectionUtil.isClassAvailable("java.util.List")