Add tests and missing overrides to ForwardingExtractor

libraries/extractor/src/main/java/androidx/media3/extractor/ForwardingExtractor.java

@@ -17,6 +17,7 @@ package androidx.media3.extractor;
 
 import androidx.media3.common.util.UnstableApi;
 import java.io.IOException;
+import java.util.List;
 
 /**
  * An overridable {@link Extractor} implementation forwarding all methods to an underlying
@@ -35,6 +36,11 @@ public class ForwardingExtractor implements Extractor {
     return delegate.sniff(input);
   }
 
+  @Override
+  public List<SniffFailure> getSniffFailureDetails() {
+    return delegate.getSniffFailureDetails();
+  }
+
   @Override
   public void init(ExtractorOutput output) {
     delegate.init(output);
@@ -55,4 +61,9 @@ public class ForwardingExtractor implements Extractor {
   public void release() {
     delegate.release();
   }
+
+  @Override
+  public Extractor getUnderlyingImplementation() {
+    return delegate.getUnderlyingImplementation();
+  }
 }

libraries/extractor/src/test/java/androidx/media3/extractor/ForwardingExtractorOutputTest.java

@@ -0,0 +1,23 @@
+package androidx.media3.extractor;
+
+import static androidx.media3.test.utils.TestUtil.assertForwardingClassForwardsAllMethods;
+import static androidx.media3.test.utils.TestUtil.assertForwardingClassOverridesAllMethods;
+
+import androidx.test.ext.junit.runners.AndroidJUnit4;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+@RunWith(AndroidJUnit4.class)
+public class ForwardingExtractorOutputTest {
+
+  @Test
+  public void overridesAllMethods() throws Exception {
+    assertForwardingClassOverridesAllMethods(
+        ExtractorOutput.class, ForwardingExtractorOutput.class);
+  }
+
+  @Test
+  public void forwardsAllMethods() throws Exception {
+    assertForwardingClassForwardsAllMethods(ExtractorOutput.class, ForwardingExtractorOutput::new);
+  }
+}

libraries/extractor/src/test/java/androidx/media3/extractor/ForwardingExtractorTest.java

@@ -0,0 +1,22 @@
+package androidx.media3.extractor;
+
+import static androidx.media3.test.utils.TestUtil.assertForwardingClassForwardsAllMethods;
+import static androidx.media3.test.utils.TestUtil.assertForwardingClassOverridesAllMethods;
+
+import androidx.test.ext.junit.runners.AndroidJUnit4;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+@RunWith(AndroidJUnit4.class)
+public class ForwardingExtractorTest {
+
+  @Test
+  public void overridesAllMethods() throws Exception {
+    assertForwardingClassOverridesAllMethods(Extractor.class, ForwardingExtractor.class);
+  }
+
+  @Test
+  public void forwardsAllMethods() throws Exception {
+    assertForwardingClassForwardsAllMethods(Extractor.class, ForwardingExtractor::new);
+  }
+}

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

@@ -18,6 +18,8 @@ package androidx.media3.test.utils;
 import static androidx.media3.common.util.Assertions.checkNotNull;
 import static androidx.media3.common.util.Assertions.checkState;
 import static com.google.common.truth.Truth.assertThat;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.verify;
 
 import android.content.Context;
 import android.database.sqlite.SQLiteDatabase;
@@ -36,6 +38,7 @@ import androidx.media3.common.MediaMetadata;
 import androidx.media3.common.StreamKey;
 import androidx.media3.common.Timeline;
 import androidx.media3.common.TrackGroup;
+import androidx.media3.common.util.NullableType;
 import androidx.media3.common.util.UnstableApi;
 import androidx.media3.common.util.Util;
 import androidx.media3.database.DatabaseProvider;
@@ -51,6 +54,7 @@ import androidx.media3.extractor.ExtractorInput;
 import androidx.media3.extractor.PositionHolder;
 import androidx.media3.extractor.SeekMap;
 import androidx.media3.extractor.metadata.MetadataInputBuffer;
+import com.google.common.base.Function;
 import com.google.common.collect.BoundType;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.Range;
@@ -63,6 +67,8 @@ import java.io.FileInputStream;
 import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
+import java.lang.reflect.Array;
+import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
 import java.lang.reflect.Modifier;
 import java.nio.ByteBuffer;
@@ -618,6 +624,42 @@ public class TestUtil {
     return list;
   }
 
+  /**
+   * Use reflection to assert that every 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)) {
+      assertThat(
+              forwardingType
+                  .getDeclaredMethod(method.getName(), method.getParameterTypes())
+                  .getDeclaringClass())
+          .isEqualTo(forwardingType);
+    }
+  }
+
+  /**
+   * 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.
+   */
+  public static <T, F extends T> void assertForwardingClassForwardsAllMethods(
+      Class<T> superType, Function<T, F> forwardingInstanceFactory)
+      throws InvocationTargetException, IllegalAccessException {
+    for (Method method : getPublicMethods(superType)) {
+      T delegate = mock(superType);
+      F forwardingInstance = forwardingInstanceFactory.apply(delegate);
+      @NullableType Object[] parameters = new Object[method.getParameterCount()];
+      for (int i = 0; i < method.getParameterCount(); i++) {
+        // Get a default value of the right type by creating a single-element array. This gives us
+        // null for object types, and the 'default' value for primitives.
+        parameters[i] = Array.get(Array.newInstance(method.getParameterTypes()[i], 1), 0);
+      }
+      method.invoke(forwardingInstance, parameters);
+      method.invoke(verify(delegate), parameters);
+    }
+  }
+
   /** Returns a {@link MediaItem} that has all fields set to non-default values. */
   public static MediaItem buildFullyCustomizedMediaItem() {
     return new MediaItem.Builder()