diff --git a/packages/SystemUI/tests/src/com/android/systemui/statusbar/notification/stack/NotificationStackScrollLayoutTest.java b/packages/SystemUI/tests/src/com/android/systemui/statusbar/notification/stack/NotificationStackScrollLayoutTest.java
index 13501f3e25601..a4ee349f5b710 100644
--- a/packages/SystemUI/tests/src/com/android/systemui/statusbar/notification/stack/NotificationStackScrollLayoutTest.java
+++ b/packages/SystemUI/tests/src/com/android/systemui/statusbar/notification/stack/NotificationStackScrollLayoutTest.java
@@ -88,6 +88,7 @@ import com.android.systemui.statusbar.phone.UnlockedScreenOffAnimationController
 
 import org.junit.Assert;
 import org.junit.Before;
+import org.junit.Ignore;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.runner.RunWith;
@@ -101,6 +102,7 @@ import java.util.ArrayList;
 /**
  * Tests for {@link NotificationStackScrollLayout}.
  */
+@Ignore("b/255552856")
 @SmallTest
 @RunWith(AndroidTestingRunner.class)
 @TestableLooper.RunWithLooper
@@ -371,6 +373,20 @@ public class NotificationStackScrollLayoutTest extends SysuiTestCase {
         mStackScroller.setExpandedHeight(expectedHeight);
     }
 
+    @Test
+    public void testAppearFractionCalculation() {
+        // appear start position
+        when(mNotificationShelf.getIntrinsicHeight()).thenReturn(100);
+        // because it's the same as shelf height, appear start position equals shelf height
+        mStackScroller.mStatusBarHeight = 100;
+        // appear end position
+        when(mEmptyShadeView.getHeight()).thenReturn(200);
+
+        assertEquals(0f, mStackScroller.calculateAppearFraction(100));
+        assertEquals(1f, mStackScroller.calculateAppearFraction(200));
+        assertEquals(0.5f, mStackScroller.calculateAppearFraction(150));
+    }
+
     @Test
     public void testAppearFractionCalculationIsNotNegativeWhenShelfBecomesSmaller() {
         // this situation might occur if status bar height is defined in pixels while shelf height
@@ -576,7 +592,6 @@ public class NotificationStackScrollLayoutTest extends SysuiTestCase {
 
     @Test
     public void testReInflatesFooterViews() {
-        when(mEmptyShadeView.getTextResource()).thenReturn(R.string.empty_shade_text);
         clearInvocations(mStackScroller);
         mStackScroller.reinflateViews();
         verify(mStackScroller).setFooterView(any());
@@ -859,7 +874,7 @@ public class NotificationStackScrollLayoutTest extends SysuiTestCase {
         mStackScroller.setHasFilteredOutSeenNotifications(true);
         mStackScroller.updateEmptyShadeView(true, false);
 
-        verify(mEmptyShadeView).setFooterText(not(eq(0)));
+        verify(mEmptyShadeView).setFooterText(not(0));
     }
 
     @Test