Add a test for handling of DRM key refresh events

In a follow-up change I will add an additional test to ensure these
events continue to be correctly handled when DefaultDrmSessionManager
has prepareCount==0 but a non-null ExoMediaDrm instance.

PiperOrigin-RevId: 376190225

library/core/src/test/java/com/google/android/exoplayer2/drm/DefaultDrmSessionManagerTest.java

@@ -25,12 +25,14 @@ import androidx.annotation.Nullable;
 import androidx.test.ext.junit.runners.AndroidJUnit4;
 import com.google.android.exoplayer2.C;
 import com.google.android.exoplayer2.Format;
+import com.google.android.exoplayer2.drm.ExoMediaDrm.AppManagedProvider;
 import com.google.android.exoplayer2.source.MediaSource;
 import com.google.android.exoplayer2.testutil.FakeExoMediaDrm;
 import com.google.android.exoplayer2.testutil.TestUtil;
 import com.google.android.exoplayer2.util.MimeTypes;
 import com.google.android.exoplayer2.util.Util;
 import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableSet;
 import java.util.UUID;
 import java.util.concurrent.atomic.AtomicInteger;
 import org.junit.Test;
@@ -408,6 +410,48 @@ public class DefaultDrmSessionManagerTest {
     drmSessionManager.release();
   }
 
+  @Test(timeout = 10_000)
+  public void keyRefreshEvent_triggersKeyRefresh() throws Exception {
+    FakeExoMediaDrm exoMediaDrm = new FakeExoMediaDrm();
+    FakeExoMediaDrm.LicenseServer licenseServer =
+        FakeExoMediaDrm.LicenseServer.allowingSchemeDatas(DRM_SCHEME_DATAS);
+    DrmSessionManager drmSessionManager =
+        new DefaultDrmSessionManager.Builder()
+            .setUuidAndExoMediaDrmProvider(DRM_SCHEME_UUID, new AppManagedProvider(exoMediaDrm))
+            .build(/* mediaDrmCallback= */ licenseServer);
+
+    drmSessionManager.prepare();
+
+    DefaultDrmSession drmSession =
+        (DefaultDrmSession)
+            checkNotNull(
+                drmSessionManager.acquireSession(
+                    /* playbackLooper= */ checkNotNull(Looper.myLooper()),
+                    /* eventDispatcher= */ null,
+                    FORMAT_WITH_DRM_INIT_DATA));
+    waitForOpenedWithKeys(drmSession);
+
+    assertThat(licenseServer.getReceivedSchemeDatas()).hasSize(1);
+
+    exoMediaDrm.triggerEvent(
+        drmSession::hasSessionId,
+        ExoMediaDrm.EVENT_KEY_REQUIRED,
+        /* extra= */ 0,
+        /* data= */ Util.EMPTY_BYTE_ARRAY);
+
+    while (licenseServer.getReceivedSchemeDatas().size() == 1) {
+      // Allow the key refresh event to be handled.
+      ShadowLooper.idleMainLooper();
+    }
+
+    assertThat(licenseServer.getReceivedSchemeDatas()).hasSize(2);
+    assertThat(ImmutableSet.copyOf(licenseServer.getReceivedSchemeDatas())).hasSize(1);
+
+    drmSession.release(/* eventDispatcher= */ null);
+    drmSessionManager.release();
+    exoMediaDrm.release();
+  }
+
   @Test
   public void managerNotPrepared_acquireSessionAndPreacquireSessionFail() throws Exception {
     FakeExoMediaDrm.LicenseServer licenseServer =

testutils/src/main/java/com/google/android/exoplayer2/testutil/FakeExoMediaDrm.java

@@ -33,6 +33,7 @@ import com.google.android.exoplayer2.drm.MediaDrmCallback;
 import com.google.android.exoplayer2.drm.MediaDrmCallbackException;
 import com.google.android.exoplayer2.util.Assertions;
 import com.google.android.exoplayer2.util.Util;
+import com.google.common.base.Predicate;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.ImmutableSet;
@@ -81,6 +82,7 @@ public final class FakeExoMediaDrm implements ExoMediaDrm {
   private final AtomicInteger sessionIdGenerator;
 
   private int referenceCount;
+  @Nullable private OnEventListener onEventListener;
 
   /**
    * Constructs an instance that returns random and unique {@code sessionIds} for subsequent calls
@@ -107,11 +109,11 @@ public final class FakeExoMediaDrm implements ExoMediaDrm {
     referenceCount = 1;
   }
 
-  // ExoMediaCrypto implementation
+  // ExoMediaDrm implementation
 
   @Override
   public void setOnEventListener(@Nullable OnEventListener listener) {
-    // Do nothing.
+    this.onEventListener = listener;
   }
 
   @Override
@@ -279,6 +281,27 @@ public final class FakeExoMediaDrm implements ExoMediaDrm {
     return FakeExoMediaCrypto.class;
   }
 
+  // Methods to facilitate testing
+
+  /**
+   * Calls {@link OnEventListener#onEvent(ExoMediaDrm, byte[], int, int, byte[])} on the attached
+   * listener (if present) once for each open session ID which passes {@code sessionIdPredicate},
+   * passing the provided values for {@code event}, {@code extra} and {@code data}.
+   */
+  public void triggerEvent(
+      Predicate<byte[]> sessionIdPredicate, int event, int extra, @Nullable byte[] data) {
+    @Nullable OnEventListener onEventListener = this.onEventListener;
+    if (onEventListener == null) {
+      return;
+    }
+    for (List<Byte> sessionId : openSessionIds) {
+      byte[] sessionIdArray = Bytes.toArray(sessionId);
+      if (sessionIdPredicate.apply(sessionIdArray)) {
+        onEventListener.onEvent(this, sessionIdArray, event, extra, data);
+      }
+    }
+  }
+
   private static ImmutableList<Byte> toByteList(byte[] byteArray) {
     return ImmutableList.copyOf(Bytes.asList(byteArray));
   }