diff --git a/src/com/android/settings/spa/notification/AppNotificationRepository.kt b/src/com/android/settings/spa/notification/AppNotificationRepository.kt
index 0f88ac9..7ec5d3e 100644
--- a/src/com/android/settings/spa/notification/AppNotificationRepository.kt
+++ b/src/com/android/settings/spa/notification/AppNotificationRepository.kt
@@ -30,7 +30,9 @@
 import android.os.RemoteException
 import android.os.ServiceManager
 import android.util.Log
-import com.android.settingslib.spaprivileged.model.app.PackageManagers.hasRequestPermission
+import com.android.settings.R
+import com.android.settingslib.spaprivileged.model.app.IPackageManagers
+import com.android.settingslib.spaprivileged.model.app.PackageManagers
 import java.util.concurrent.TimeUnit
 import kotlin.math.max
 import kotlin.math.roundToInt
@@ -48,21 +50,23 @@
     var sentCount: Int = 0,
 )
 
-class AppNotificationRepository(private val context: Context) {
+class AppNotificationRepository(
+    private val context: Context,
+    private val packageManagers: IPackageManagers = PackageManagers,
+    private val usageStatsManager: IUsageStatsManager = IUsageStatsManager.Stub.asInterface(
+        ServiceManager.getService(Context.USAGE_STATS_SERVICE)
+    ),
+    private val notificationManager: INotificationManager = INotificationManager.Stub.asInterface(
+        ServiceManager.getService(Context.NOTIFICATION_SERVICE)
+    ),
+) {
     fun getAggregatedUsageEvents(userIdFlow: Flow<Int>): Flow<Map<String, NotificationSentState>> =
         userIdFlow.map { userId ->
             val aggregatedStats = mutableMapOf<String, NotificationSentState>()
-            queryEventsForUser(userId)?.let { events ->
-                val event = UsageEvents.Event()
-                while (events.hasNextEvent()) {
-                    events.getNextEvent(event)
-                    if (event.eventType == UsageEvents.Event.NOTIFICATION_INTERRUPTION) {
-                        aggregatedStats.getOrPut(event.packageName, ::NotificationSentState)
-                            .apply {
-                                lastSent = max(lastSent, event.timeStamp)
-                                sentCount++
-                            }
-                    }
+            queryEventsForUser(userId).forEachNotificationEvent { event ->
+                aggregatedStats.getOrPut(event.packageName, ::NotificationSentState).apply {
+                    lastSent = max(lastSent, event.timeStamp)
+                    sentCount++
                 }
             }
             aggregatedStats
@@ -90,7 +94,9 @@
         // If the app targets T but has not requested the permission, we cannot change the
         // permission state.
         return app.targetSdkVersion < Build.VERSION_CODES.TIRAMISU ||
-            app.hasRequestPermission(Manifest.permission.POST_NOTIFICATIONS)
+            with(packageManagers) {
+                app.hasRequestPermission(Manifest.permission.POST_NOTIFICATIONS)
+            }
     }
 
     fun setEnabled(app: ApplicationInfo, enabled: Boolean): Boolean {
@@ -109,6 +115,19 @@
         }
     }
 
+    fun calculateFrequencySummary(sentCount: Int): String {
+        val dailyFrequency = (sentCount.toFloat() / DAYS_TO_CHECK).roundToInt()
+        return if (dailyFrequency > 0) {
+            context.resources.getQuantityString(
+                R.plurals.notifications_sent_daily, dailyFrequency, dailyFrequency
+            )
+        } else {
+            context.resources.getQuantityString(
+                R.plurals.notifications_sent_weekly, sentCount, sentCount
+            )
+        }
+    }
+
     private fun updateChannel(app: ApplicationInfo, channel: NotificationChannel) {
         notificationManager.updateNotificationChannelForPackage(app.packageName, app.uid, channel)
     }
@@ -124,21 +143,16 @@
     companion object {
         private const val TAG = "AppNotificationsRepo"
 
-        const val DAYS_TO_CHECK = 7L
+        private const val DAYS_TO_CHECK = 7L
 
-        private val usageStatsManager by lazy {
-            IUsageStatsManager.Stub.asInterface(
-                ServiceManager.getService(Context.USAGE_STATS_SERVICE)
-            )
+        private fun UsageEvents?.forEachNotificationEvent(action: (UsageEvents.Event) -> Unit) {
+            this ?: return
+            val event = UsageEvents.Event()
+            while (getNextEvent(event)) {
+                if (event.eventType == UsageEvents.Event.NOTIFICATION_INTERRUPTION) {
+                    action(event)
+                }
+            }
         }
-
-        private val notificationManager by lazy {
-            INotificationManager.Stub.asInterface(
-                ServiceManager.getService(Context.NOTIFICATION_SERVICE)
-            )
-        }
-
-        fun calculateDailyFrequent(sentCount: Int): Int =
-            (sentCount.toFloat() / DAYS_TO_CHECK).roundToInt()
     }
 }
diff --git a/src/com/android/settings/spa/notification/AppNotificationsListModel.kt b/src/com/android/settings/spa/notification/AppNotificationsListModel.kt
index c7baa03..29c8a2b 100644
--- a/src/com/android/settings/spa/notification/AppNotificationsListModel.kt
+++ b/src/com/android/settings/spa/notification/AppNotificationsListModel.kt
@@ -92,7 +92,7 @@
     override fun getSummary(option: Int, record: AppNotificationsRecord) = record.sentState?.let {
         when (option.toSpinnerItem()) {
             SpinnerItem.MostRecent -> stateOf(formatLastSent(it.lastSent))
-            SpinnerItem.MostFrequent -> stateOf(calculateFrequent(it.sentCount))
+            SpinnerItem.MostFrequent -> stateOf(repository.calculateFrequencySummary(it.sentCount))
             else -> null
         }
     }
@@ -109,19 +109,6 @@
             RelativeDateTimeFormatter.Style.LONG,
         ).toString()
 
-    private fun calculateFrequent(sentCount: Int): String {
-        val dailyFrequent = AppNotificationRepository.calculateDailyFrequent(sentCount)
-        return if (dailyFrequent > 0) {
-            context.resources.getQuantityString(
-                R.plurals.notifications_sent_daily, dailyFrequent, dailyFrequent
-            )
-        } else {
-            context.resources.getQuantityString(
-                R.plurals.notifications_sent_weekly, sentCount, sentCount
-            )
-        }
-    }
-
     @Composable
     override fun AppListItemModel<AppNotificationsRecord>.AppItem() {
         AppListSwitchItem(
diff --git a/tests/spa_unit/src/com/android/settings/spa/notification/AppNotificationRepositoryTest.kt b/tests/spa_unit/src/com/android/settings/spa/notification/AppNotificationRepositoryTest.kt
new file mode 100644
index 0000000..7a5bc9f
--- /dev/null
+++ b/tests/spa_unit/src/com/android/settings/spa/notification/AppNotificationRepositoryTest.kt
@@ -0,0 +1,236 @@
+/*
+ * Copyright (C) 2022 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.settings.spa.notification
+
+import android.Manifest
+import android.app.INotificationManager
+import android.app.NotificationChannel
+import android.app.NotificationManager.IMPORTANCE_DEFAULT
+import android.app.NotificationManager.IMPORTANCE_NONE
+import android.app.NotificationManager.IMPORTANCE_UNSPECIFIED
+import android.app.usage.IUsageStatsManager
+import android.app.usage.UsageEvents
+import android.content.Context
+import android.content.pm.ApplicationInfo
+import android.os.Build
+import androidx.test.core.app.ApplicationProvider
+import androidx.test.ext.junit.runners.AndroidJUnit4
+import com.android.settingslib.spa.testutils.any
+import com.android.settingslib.spaprivileged.model.app.IPackageManagers
+import com.google.common.truth.Truth.assertThat
+import kotlinx.coroutines.ExperimentalCoroutinesApi
+import kotlinx.coroutines.flow.first
+import kotlinx.coroutines.flow.flowOf
+import kotlinx.coroutines.test.runTest
+import org.junit.Before
+import org.junit.Rule
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.mockito.Mock
+import org.mockito.Mockito.eq
+import org.mockito.Mockito.verify
+import org.mockito.junit.MockitoJUnit
+import org.mockito.junit.MockitoRule
+import org.mockito.Mockito.`when` as whenever
+
+@OptIn(ExperimentalCoroutinesApi::class)
+@RunWith(AndroidJUnit4::class)
+class AppNotificationRepositoryTest {
+    @get:Rule
+    val mockito: MockitoRule = MockitoJUnit.rule()
+
+    private val context: Context = ApplicationProvider.getApplicationContext()
+
+    @Mock
+    private lateinit var packageManagers: IPackageManagers
+
+    @Mock
+    private lateinit var usageStatsManager: IUsageStatsManager
+
+    @Mock
+    private lateinit var notificationManager: INotificationManager
+
+    private lateinit var repository: AppNotificationRepository
+
+    @Before
+    fun setUp() {
+        repository = AppNotificationRepository(
+            context,
+            packageManagers,
+            usageStatsManager,
+            notificationManager,
+        )
+    }
+
+    private fun mockOnlyHasDefaultChannel(): NotificationChannel {
+        whenever(notificationManager.onlyHasDefaultChannel(APP.packageName, APP.uid))
+            .thenReturn(true)
+        val channel =
+            NotificationChannel(NotificationChannel.DEFAULT_CHANNEL_ID, null, IMPORTANCE_DEFAULT)
+        whenever(
+            notificationManager.getNotificationChannelForPackage(
+                APP.packageName, APP.uid, NotificationChannel.DEFAULT_CHANNEL_ID, null, true
+            )
+        ).thenReturn(channel)
+        return channel
+    }
+
+    @Test
+    fun getAggregatedUsageEvents() = runTest {
+        val events = listOf(
+            UsageEvents.Event().apply {
+                mEventType = UsageEvents.Event.NOTIFICATION_INTERRUPTION
+                mPackage = PACKAGE_NAME
+                mTimeStamp = 2
+            },
+            UsageEvents.Event().apply {
+                mEventType = UsageEvents.Event.NOTIFICATION_INTERRUPTION
+                mPackage = PACKAGE_NAME
+                mTimeStamp = 3
+            },
+            UsageEvents.Event().apply {
+                mEventType = UsageEvents.Event.NOTIFICATION_INTERRUPTION
+                mPackage = PACKAGE_NAME
+                mTimeStamp = 6
+            },
+        )
+        whenever(usageStatsManager.queryEventsForUser(any(), any(), eq(USER_ID), any()))
+            .thenReturn(UsageEvents(events, arrayOf()))
+
+        val usageEvents = repository.getAggregatedUsageEvents(flowOf(USER_ID)).first()
+
+        assertThat(usageEvents).containsExactly(
+            PACKAGE_NAME, NotificationSentState(lastSent = 6, sentCount = 3),
+        )
+    }
+
+    @Test
+    fun isEnabled() {
+        whenever(notificationManager.areNotificationsEnabledForPackage(APP.packageName, APP.uid))
+            .thenReturn(true)
+
+        val isEnabled = repository.isEnabled(APP)
+
+        assertThat(isEnabled).isTrue()
+    }
+
+    @Test
+    fun isChangeable_importanceLocked() {
+        whenever(notificationManager.isImportanceLocked(APP.packageName, APP.uid)).thenReturn(true)
+
+        val isChangeable = repository.isChangeable(APP)
+
+        assertThat(isChangeable).isFalse()
+    }
+
+    @Test
+    fun isChangeable_appTargetS() {
+        val targetSApp = ApplicationInfo().apply {
+            targetSdkVersion = Build.VERSION_CODES.S
+        }
+
+        val isChangeable = repository.isChangeable(targetSApp)
+
+        assertThat(isChangeable).isTrue()
+    }
+
+    @Test
+    fun isChangeable_appTargetTiramisuWithoutNotificationPermission() {
+        val targetTiramisuApp = ApplicationInfo().apply {
+            targetSdkVersion = Build.VERSION_CODES.TIRAMISU
+        }
+        with(packageManagers) {
+            whenever(targetTiramisuApp.hasRequestPermission(Manifest.permission.POST_NOTIFICATIONS))
+                .thenReturn(false)
+        }
+
+        val isChangeable = repository.isChangeable(targetTiramisuApp)
+
+        assertThat(isChangeable).isFalse()
+    }
+
+    @Test
+    fun isChangeable_appTargetTiramisuWithNotificationPermission() {
+        val targetTiramisuApp = ApplicationInfo().apply {
+            targetSdkVersion = Build.VERSION_CODES.TIRAMISU
+        }
+        with(packageManagers) {
+            whenever(targetTiramisuApp.hasRequestPermission(Manifest.permission.POST_NOTIFICATIONS))
+                .thenReturn(true)
+        }
+
+        val isChangeable = repository.isChangeable(targetTiramisuApp)
+
+        assertThat(isChangeable).isTrue()
+    }
+
+    @Test
+    fun setEnabled_toTrueWhenOnlyHasDefaultChannel() {
+        val channel = mockOnlyHasDefaultChannel()
+
+        repository.setEnabled(app = APP, enabled = true)
+
+        verify(notificationManager)
+            .updateNotificationChannelForPackage(APP.packageName, APP.uid, channel)
+        assertThat(channel.importance).isEqualTo(IMPORTANCE_UNSPECIFIED)
+    }
+
+    @Test
+    fun setEnabled_toFalseWhenOnlyHasDefaultChannel() {
+        val channel = mockOnlyHasDefaultChannel()
+
+        repository.setEnabled(app = APP, enabled = false)
+
+        verify(notificationManager)
+            .updateNotificationChannelForPackage(APP.packageName, APP.uid, channel)
+        assertThat(channel.importance).isEqualTo(IMPORTANCE_NONE)
+    }
+
+    @Test
+    fun setEnabled_toTrueWhenNotOnlyHasDefaultChannel() {
+        whenever(notificationManager.onlyHasDefaultChannel(APP.packageName, APP.uid))
+            .thenReturn(false)
+
+        repository.setEnabled(app = APP, enabled = true)
+
+        verify(notificationManager)
+            .setNotificationsEnabledForPackage(APP.packageName, APP.uid, true)
+    }
+
+    @Test
+    fun calculateFrequencySummary_daily() {
+        val summary = repository.calculateFrequencySummary(4)
+
+        assertThat(summary).isEqualTo("About 1 notification per day")
+    }
+
+    @Test
+    fun calculateFrequencySummary_weekly() {
+        val summary = repository.calculateFrequencySummary(3)
+
+        assertThat(summary).isEqualTo("About 3 notifications per week")
+    }
+
+    private companion object {
+        const val USER_ID = 0
+        const val PACKAGE_NAME = "package.name"
+        val APP = ApplicationInfo().apply {
+            packageName = PACKAGE_NAME
+            uid = 123
+        }
+    }
+}
\ No newline at end of file