Refactor `ApnPushNotificationSchedulerTest` to use a `Clock`

service/src/main/java/org/whispersystems/textsecuregcm/push/ApnPushNotificationScheduler.java

@@ -12,6 +12,7 @@ import io.lettuce.core.cluster.SlotHash;
 import io.micrometer.core.instrument.Counter;
 import io.micrometer.core.instrument.Metrics;
 import java.io.IOException;
+import java.time.Clock;
 import java.util.Collections;
 import java.util.List;
 import java.util.Optional;
@@ -48,6 +49,7 @@ public class ApnPushNotificationScheduler implements Managed {
   private final APNSender apnSender;
   private final AccountsManager accountsManager;
   private final FaultTolerantRedisCluster pushSchedulingCluster;
+  private final Clock clock;
 
   private final ClusterLuaScript getPendingVoipDestinationsScript;
   private final ClusterLuaScript insertPendingVoipDestinationScript;
@@ -109,13 +111,22 @@ public class ApnPushNotificationScheduler implements Managed {
   }
 
   public ApnPushNotificationScheduler(FaultTolerantRedisCluster pushSchedulingCluster,
-                            APNSender apnSender,
+      APNSender apnSender,
-                            AccountsManager accountsManager)
+      AccountsManager accountsManager) throws IOException {
-      throws IOException
+
-  {
+    this(pushSchedulingCluster, apnSender, accountsManager, Clock.systemUTC());
+  }
+
+  @VisibleForTesting
+  ApnPushNotificationScheduler(FaultTolerantRedisCluster pushSchedulingCluster,
+      APNSender apnSender,
+      AccountsManager accountsManager,
+      Clock clock) throws IOException {
+
     this.apnSender = apnSender;
     this.accountsManager = accountsManager;
     this.pushSchedulingCluster = pushSchedulingCluster;
+    this.clock = clock;
 
     this.getPendingVoipDestinationsScript = ClusterLuaScript.fromResource(pushSchedulingCluster, "lua/apn/get.lua", ScriptOutputType.MULTI);
     this.insertPendingVoipDestinationScript = ClusterLuaScript.fromResource(pushSchedulingCluster, "lua/apn/insert.lua", ScriptOutputType.VALUE);
@@ -127,13 +138,8 @@ public class ApnPushNotificationScheduler implements Managed {
   }
 
   public void scheduleRecurringVoipNotification(Account account, Device device) {
-    scheduleRecurringVoipNotification(account, device, System.currentTimeMillis());
-  }
-
-  @VisibleForTesting
-  void scheduleRecurringVoipNotification(Account account, Device device, long timestamp) {
     sent.increment();
-    insertRecurringVoipNotificationEntry(account, device, timestamp + (15 * 1000), (15 * 1000));
+    insertRecurringVoipNotificationEntry(account, device, clock.millis() + (15 * 1000), (15 * 1000));
   }
 
   public void cancelRecurringVoipNotification(Account account, Device device) {
@@ -170,7 +176,7 @@ public class ApnPushNotificationScheduler implements Managed {
 
     long deviceLastSeen = device.getLastSeen();
 
-    if (deviceLastSeen < System.currentTimeMillis() - TimeUnit.DAYS.toMillis(7)) {
+    if (deviceLastSeen < clock.millis() - TimeUnit.DAYS.toMillis(7)) {
       evicted.increment();
       removeRecurringVoipNotificationEntry(account, device);
       return;
@@ -214,7 +220,7 @@ public class ApnPushNotificationScheduler implements Managed {
   List<String> getPendingDestinationsForRecurringVoipNotifications(final int slot, final int limit) {
     return (List<String>) getPendingVoipDestinationsScript.execute(
         List.of(getPendingRecurringVoipNotificationQueueKey(slot)),
-        List.of(String.valueOf(System.currentTimeMillis()), String.valueOf(limit)));
+        List.of(String.valueOf(clock.millis()), String.valueOf(limit)));
   }
 
   private void insertRecurringVoipNotificationEntry(final Account account, final Device device, final long timestamp, final long interval) {

service/src/test/java/org/whispersystems/textsecuregcm/push/ApnPushNotificationSchedulerTest.java

@@ -12,6 +12,7 @@ import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 
 import io.lettuce.core.cluster.SlotHash;
+import java.time.Clock;
 import java.util.List;
 import java.util.Optional;
 import java.util.UUID;
@@ -35,6 +36,7 @@ class ApnPushNotificationSchedulerTest {
   private Device device;
 
   private APNSender apnSender;
+  private Clock clock;
 
   private ApnPushNotificationScheduler apnPushNotificationScheduler;
 
@@ -61,19 +63,23 @@ class ApnPushNotificationSchedulerTest {
     when(accountsManager.getByAccountIdentifier(ACCOUNT_UUID)).thenReturn(Optional.of(account));
 
     apnSender = mock(APNSender.class);
+    clock = mock(Clock.class);
 
-    apnPushNotificationScheduler = new ApnPushNotificationScheduler(REDIS_CLUSTER_EXTENSION.getRedisCluster(), apnSender, accountsManager);
+    apnPushNotificationScheduler = new ApnPushNotificationScheduler(REDIS_CLUSTER_EXTENSION.getRedisCluster(), apnSender, accountsManager, clock);
   }
 
   @Test
   void testClusterInsert() {
     final String endpoint = apnPushNotificationScheduler.getEndpointKey(account, device);
+    final long currentTimeMillis = System.currentTimeMillis();
 
     assertTrue(
         apnPushNotificationScheduler.getPendingDestinationsForRecurringVoipNotifications(SlotHash.getSlot(endpoint), 1).isEmpty());
 
-    apnPushNotificationScheduler.scheduleRecurringVoipNotification(account, device, System.currentTimeMillis() - 30_000);
+    when(clock.millis()).thenReturn(currentTimeMillis - 30_000);
+    apnPushNotificationScheduler.scheduleRecurringVoipNotification(account, device);
 
+    when(clock.millis()).thenReturn(currentTimeMillis);
     final List<String> pendingDestinations = apnPushNotificationScheduler.getPendingDestinationsForRecurringVoipNotifications(SlotHash.getSlot(endpoint), 2);
     assertEquals(1, pendingDestinations.size());
 
@@ -91,12 +97,15 @@ class ApnPushNotificationSchedulerTest {
   @Test
   void testProcessNextSlot() {
     final ApnPushNotificationScheduler.NotificationWorker worker = apnPushNotificationScheduler.new NotificationWorker();
+    final long currentTimeMillis = System.currentTimeMillis();
 
-    apnPushNotificationScheduler.scheduleRecurringVoipNotification(account, device, System.currentTimeMillis() - 30_000);
+    when(clock.millis()).thenReturn(currentTimeMillis - 30_000);
+    apnPushNotificationScheduler.scheduleRecurringVoipNotification(account, device);
 
     final int slot = SlotHash.getSlot(apnPushNotificationScheduler.getEndpointKey(account, device));
     final int previousSlot = (slot + SlotHash.SLOT_COUNT - 1) % SlotHash.SLOT_COUNT;
 
+    when(clock.millis()).thenReturn(currentTimeMillis);
     REDIS_CLUSTER_EXTENSION.getRedisCluster().withCluster(connection -> connection.sync()
         .set(ApnPushNotificationScheduler.NEXT_SLOT_TO_PERSIST_KEY, String.valueOf(previousSlot)));