test: update StorageITRunner to search parent classes for annotations rather than only the current class (googleapis#3001)

Author: BenWhitehead

google-cloud-storage/src/test/java/com/google/cloud/storage/it/runner/StorageITRunner.java

@@ -27,12 +27,14 @@
 import com.google.cloud.storage.it.runner.registry.Registry;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableSet;
+import java.lang.annotation.Annotation;
 import java.util.List;
 import java.util.Locale;
 import java.util.concurrent.locks.Lock;
 import java.util.concurrent.locks.ReentrantLock;
 import java.util.function.Function;
 import java.util.stream.Stream;
+import org.checkerframework.checker.nullness.qual.Nullable;
 import org.junit.ClassRule;
 import org.junit.runner.Description;
 import org.junit.runner.Runner;
@@ -125,8 +127,8 @@ private static List<Runner> computeRunners(Class<?> klass, Registry registry)
 
     Parameterized parameterized = testClass.getAnnotation(Parameterized.class);
 
-    CrossRun crossRun = testClass.getAnnotation(CrossRun.class);
-    SingleBackend singleBackend = testClass.getAnnotation(SingleBackend.class);
+    CrossRun crossRun = getClassAnnotation(testClass, CrossRun.class);
+    SingleBackend singleBackend = getClassAnnotation(testClass, SingleBackend.class);
     StorageITRunner.validateBackendAnnotations(crossRun, singleBackend);
 
     final ImmutableList<?> parameters;
@@ -202,6 +204,19 @@ private static List<Runner> computeRunners(Class<?> klass, Registry registry)
     }
   }
 
+  private static <A extends Annotation> @Nullable A getClassAnnotation(
+      TestClass testClass, Class<A> annotation) {
+    A a = testClass.getAnnotation(annotation);
+    if (a != null) {
+      return a;
+    }
+    Class<?> parent = testClass.getJavaClass().getSuperclass();
+    if (parent == null) {
+      return null;
+    }
+    return getClassAnnotation(new TestClass(parent), annotation);
+  }
+
   private static String fmtParam(Object param) {
     return String.format(Locale.US, "[%s]", param.toString());
   }

google-cloud-storage/src/test/java/com/google/cloud/storage/it/runner/StorageITRunnerTest.java

@@ -0,0 +1,46 @@
+/*
+ * Copyright 2025 Google LLC
+ *
+ * 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.
+ */
+
+package com.google.cloud.storage.it.runner;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import com.google.cloud.storage.TransportCompatibility.Transport;
+import com.google.cloud.storage.it.runner.annotations.Backend;
+import com.google.cloud.storage.it.runner.annotations.CrossRun;
+import com.google.cloud.storage.it.runner.annotations.Inject;
+import org.junit.Test;
+import org.junit.experimental.runners.Enclosed;
+import org.junit.runner.RunWith;
+
+@RunWith(Enclosed.class)
+public final class StorageITRunnerTest {
+
+  @RunWith(StorageITRunner.class)
+  @CrossRun(
+      backends = {Backend.PROD},
+      transports = {Transport.HTTP, Transport.GRPC})
+  public abstract static class Parent {
+    @Inject public Transport transport;
+  }
+
+  public static final class Child extends Parent {
+    @Test
+    public void transport() {
+      assertThat(transport).isNotNull();
+    }
+  }
+}