diff --git a/quickstep/src/com/android/quickstep/GestureState.java b/quickstep/src/com/android/quickstep/GestureState.java
index 703db07..bcd9687 100644
--- a/quickstep/src/com/android/quickstep/GestureState.java
+++ b/quickstep/src/com/android/quickstep/GestureState.java
@@ -21,6 +21,8 @@
 import static com.android.quickstep.MultiStateCallback.DEBUG_STATES;
 import static com.android.quickstep.util.ActiveGestureErrorDetector.GestureEvent.SET_END_TARGET;
 import static com.android.quickstep.util.ActiveGestureErrorDetector.GestureEvent.SET_END_TARGET_HOME;
+import static com.android.quickstep.util.ActiveGestureErrorDetector.GestureEvent.SET_END_TARGET_LAST_TASK;
+import static com.android.quickstep.util.ActiveGestureErrorDetector.GestureEvent.SET_END_TARGET_NEW_TASK;
 
 import android.annotation.Nullable;
 import android.annotation.TargetApi;
@@ -335,9 +337,13 @@
             case HOME:
                 ActiveGestureLog.INSTANCE.trackEvent(SET_END_TARGET_HOME);
                 break;
-            case RECENTS:
             case NEW_TASK:
+                ActiveGestureLog.INSTANCE.trackEvent(SET_END_TARGET_NEW_TASK);
+                break;
             case LAST_TASK:
+                ActiveGestureLog.INSTANCE.trackEvent(SET_END_TARGET_LAST_TASK);
+                break;
+            case RECENTS:
             default:
                 // No-Op
         }
diff --git a/quickstep/src/com/android/quickstep/RecentsAnimationCallbacks.java b/quickstep/src/com/android/quickstep/RecentsAnimationCallbacks.java
index 887fd54..04c0ab0 100644
--- a/quickstep/src/com/android/quickstep/RecentsAnimationCallbacks.java
+++ b/quickstep/src/com/android/quickstep/RecentsAnimationCallbacks.java
@@ -28,6 +28,7 @@
 
 import com.android.launcher3.Utilities;
 import com.android.launcher3.util.Preconditions;
+import com.android.quickstep.util.ActiveGestureErrorDetector;
 import com.android.quickstep.util.ActiveGestureLog;
 import com.android.systemui.shared.recents.model.ThumbnailData;
 import com.android.systemui.shared.system.RecentsAnimationControllerCompat;
@@ -137,7 +138,8 @@
     @Override
     public void onTasksAppeared(RemoteAnimationTargetCompat[] apps) {
         Utilities.postAsyncCallback(MAIN_EXECUTOR.getHandler(), () -> {
-            ActiveGestureLog.INSTANCE.addLog("onTasksAppeared");
+            ActiveGestureLog.INSTANCE.addLog("onTasksAppeared",
+                    ActiveGestureErrorDetector.GestureEvent.TASK_APPEARED);
             for (RecentsAnimationListener listener : getListeners()) {
                 listener.onTasksAppeared(apps);
             }
diff --git a/quickstep/src/com/android/quickstep/util/ActiveGestureErrorDetector.java b/quickstep/src/com/android/quickstep/util/ActiveGestureErrorDetector.java
index d2d1233..53e0c2b 100644
--- a/quickstep/src/com/android/quickstep/util/ActiveGestureErrorDetector.java
+++ b/quickstep/src/com/android/quickstep/util/ActiveGestureErrorDetector.java
@@ -33,10 +33,10 @@
      * Enums associated to gesture navigation events.
      */
     public enum GestureEvent {
-        MOTION_DOWN, MOTION_UP, SET_END_TARGET, SET_END_TARGET_HOME, ON_SETTLED_ON_END_TARGET,
-        START_RECENTS_ANIMATION, FINISH_RECENTS_ANIMATION, CANCEL_RECENTS_ANIMATION,
-        SET_ON_PAGE_TRANSITION_END_CALLBACK, CANCEL_CURRENT_ANIMATION, CLEANUP_SCREENSHOT,
-        SCROLLER_ANIMATION_ABORTED,
+        MOTION_DOWN, MOTION_UP, SET_END_TARGET, SET_END_TARGET_HOME, SET_END_TARGET_LAST_TASK,
+        SET_END_TARGET_NEW_TASK, ON_SETTLED_ON_END_TARGET, START_RECENTS_ANIMATION,
+        FINISH_RECENTS_ANIMATION, CANCEL_RECENTS_ANIMATION, SET_ON_PAGE_TRANSITION_END_CALLBACK,
+        CANCEL_CURRENT_ANIMATION, CLEANUP_SCREENSHOT, SCROLLER_ANIMATION_ABORTED, TASK_APPEARED,
 
         /**
          * These GestureEvents are specifically associated to state flags that get set in
@@ -134,6 +134,15 @@
                                         + " settling on end target.",
                                 writer);
                         break;
+                    case TASK_APPEARED:
+                        errorDetected |= printErrorIfTrue(
+                                !encounteredEvents.contains(GestureEvent.SET_END_TARGET_LAST_TASK)
+                                        && !encounteredEvents.contains(
+                                        GestureEvent.SET_END_TARGET_NEW_TASK),
+                                /* errorMessage= */ prefix + "\t\tonTasksAppeared called "
+                                        + "before/without setting end target to last or new task",
+                                writer);
+                        break;
                     case STATE_GESTURE_COMPLETED:
                         errorDetected |= printErrorIfTrue(
                                 !encounteredEvents.contains(GestureEvent.MOTION_UP),
@@ -289,6 +298,21 @@
                             + "the task screenshot wasn't cleaned up.",
                     writer);
 
+            errorDetected |= printErrorIfTrue(
+                    /* condition= */ encounteredEvents.contains(
+                            GestureEvent.SET_END_TARGET_LAST_TASK)
+                            && !encounteredEvents.contains(GestureEvent.TASK_APPEARED),
+                    /* errorMessage= */ prefix + "\t\tend target set to last task, but "
+                            + "onTaskAppeared wasn't called.",
+                    writer);
+            errorDetected |= printErrorIfTrue(
+                    /* condition= */ encounteredEvents.contains(
+                            GestureEvent.SET_END_TARGET_NEW_TASK)
+                            && !encounteredEvents.contains(GestureEvent.TASK_APPEARED),
+                    /* errorMessage= */ prefix + "\t\tend target set to new task, but "
+                            + "onTaskAppeared wasn't called.",
+                    writer);
+
             if (!errorDetected) {
                 writer.println(prefix + "\t\tNo errors detected.");
             }