Add ForwardingTimelineTest

PiperOrigin-RevId: 703029260

libraries/exoplayer/src/test/java/androidx/media3/exoplayer/source/ForwardingTimelineTest.java

@@ -0,0 +1,46 @@
+/*
+ * Copyright 2024 The Android Open Source Project
+ *
+ * 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 androidx.media3.exoplayer.source;
+
+import static androidx.media3.test.utils.TestUtil.assertForwardingClassForwardsAllMethodsExcept;
+import static androidx.media3.test.utils.TestUtil.assertForwardingClassOverridesAllMethodsExcept;
+
+import androidx.media3.common.Timeline;
+import androidx.test.ext.junit.runners.AndroidJUnit4;
+import com.google.common.collect.ImmutableSet;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+/** Unit tests for {@link ForwardingTimeline}. */
+@RunWith(AndroidJUnit4.class)
+public class ForwardingTimelineTest {
+
+  @Test
+  public void overridesAllMethods() throws Exception {
+    assertForwardingClassOverridesAllMethodsExcept(
+        Timeline.class,
+        ForwardingTimeline.class,
+        ImmutableSet.of("equals", "hashCode", "getPeriodByUid"));
+  }
+
+  @Test
+  public void forwardsAllMethods() throws Exception {
+    assertForwardingClassForwardsAllMethodsExcept(
+        Timeline.class,
+        delegate -> new ForwardingTimeline(delegate) {},
+        ImmutableSet.of("equals", "hashCode", "getPeriodByUid"));
+  }
+}

libraries/test_utils/src/main/java/androidx/media3/test/utils/TestUtil.java

@@ -58,6 +58,7 @@ import com.google.common.base.Function;
 import com.google.common.collect.BoundType;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableSet;
+import com.google.common.collect.Iterables;
 import com.google.common.collect.Ordering;
 import com.google.common.collect.Range;
 import com.google.common.io.ByteStreams;
@@ -599,6 +600,17 @@ public class TestUtil {
     return buffer;
   }
 
+  /**
+   * Returns all the public overridable methods of a Java class (except those defined by {@link
+   * Object}).
+   */
+  public static Iterable<Method> getPublicOverridableMethods(Class<?> clazz) {
+    return Iterables.filter(
+        getPublicMethods(clazz),
+        method ->
+            !Modifier.isFinal(method.getModifiers()) && !Modifier.isStatic(method.getModifiers()));
+  }
+
   /** Returns all the public methods of a Java class (except those defined by {@link Object}). */
   public static List<Method> getPublicMethods(Class<?> clazz) {
     // Run a BFS over all extended types to inspect them all.
@@ -631,12 +643,25 @@ public class TestUtil {
   }
 
   /**
-   * Use reflection to assert that every method declared on {@code superType} is overridden by
-   * {@code forwardingType}.
+   * Use reflection to assert that every non-final method declared on {@code superType} is
+   * overridden by {@code forwardingType}.
    */
   public static <T> void assertForwardingClassOverridesAllMethods(
       Class<T> superType, Class<? extends T> forwardingType) throws NoSuchMethodException {
-    for (Method method : TestUtil.getPublicMethods(superType)) {
+    assertForwardingClassOverridesAllMethodsExcept(superType, forwardingType, ImmutableSet.of());
+  }
+
+  /**
+   * Use reflection to assert that every non-final, non-excluded method declared on {@code
+   * superType} is overridden by {@code forwardingType}.
+   */
+  public static <T> void assertForwardingClassOverridesAllMethodsExcept(
+      Class<T> superType, Class<? extends T> forwardingType, Set<String> excludedMethods)
+      throws NoSuchMethodException {
+    for (Method method : TestUtil.getPublicOverridableMethods(superType)) {
+      if (excludedMethods.contains(method.getName())) {
+        continue;
+      }
       assertThat(
               forwardingType
                   .getDeclaredMethod(method.getName(), method.getParameterTypes())
@@ -646,24 +671,22 @@ public class TestUtil {
   }
 
   /**
-   * Use reflection to assert calling every method declared on {@code superType} on an instance of
-   * {@code forwardingType} results in the call being forwarded to the {@code superType} delegate.
+   * Use reflection to assert that calling every non-final method declared on {@code superType} on
+   * an instance of {@code forwardingType} results in the call being forwarded to the {@code
+   * superType} delegate.
    */
   public static <T extends @NonNull Object, F extends T>
       void assertForwardingClassForwardsAllMethods(
           Class<T> superType, Function<T, F> forwardingInstanceFactory)
-          throws InvocationTargetException,
-              IllegalAccessException,
-              NoSuchMethodException,
-              InstantiationException {
+          throws InvocationTargetException, IllegalAccessException {
     assertForwardingClassForwardsAllMethodsExcept(
         superType, forwardingInstanceFactory, /* excludedMethods= */ ImmutableSet.of());
   }
 
   /**
-   * Use reflection to assert calling every non-excluded method declared on {@code superType} on an
-   * instance of {@code forwardingType} results in the call being forwarded to the {@code superType}
-   * delegate.
+   * Use reflection to assert that calling every non-final, non-excluded method declared on {@code
+   * superType} on an instance of {@code forwardingType} results in the call being forwarded to the
+   * {@code superType} delegate.
    */
   // The nullness checker is deliberately over-conservative and doesn't permit passing a null
   // parameter to method.invoke(), even if the real method does accept null. Regardless, we expect
@@ -674,11 +697,8 @@ public class TestUtil {
   public static <T extends @NonNull Object, F extends T>
       void assertForwardingClassForwardsAllMethodsExcept(
           Class<T> superType, Function<T, F> forwardingInstanceFactory, Set<String> excludedMethods)
-          throws InvocationTargetException,
-              IllegalAccessException,
-              NoSuchMethodException,
-              InstantiationException {
-    for (Method method : getPublicMethods(superType)) {
+          throws InvocationTargetException, IllegalAccessException {
+    for (Method method : getPublicOverridableMethods(superType)) {
       if (excludedMethods.contains(method.getName())) {
         continue;
       }