Merge "[DataStore] Add UT for Observer" into main

4 files changed, 140 insertions, 0 deletions

diff --git a/packages/SettingsLib/DataStore/tests/Android.bp b/packages/SettingsLib/DataStore/tests/Android.bp
new file mode 100644
index 000000000000..8770dfa013d0
--- /dev/null
+++ b/packages/SettingsLib/DataStore/tests/Android.bp
@@ -0,0 +1,24 @@
+package {
+    default_applicable_licenses: ["frameworks_base_license"],
+}
+
+android_app {
+    name: "SettingsLibDataStoreShell",
+    platform_apis: true,
+}
+
+android_robolectric_test {
+    name: "SettingsLibDataStoreTest",
+    srcs: ["src/**/*"],
+    static_libs: [
+        "SettingsLibDataStore",
+        "androidx.test.ext.junit",
+        "guava",
+        "mockito-robolectric-prebuilt", // mockito deps order matters!
+        "mockito-kotlin2",
+    ],
+    java_resource_dirs: ["config"],
+    instrumentation_for: "SettingsLibDataStoreShell",
+    coverage_libs: ["SettingsLibDataStore"],
+    upstream: true,
+}
diff --git a/packages/SettingsLib/DataStore/tests/AndroidManifest.xml b/packages/SettingsLib/DataStore/tests/AndroidManifest.xml
new file mode 100644
index 000000000000..ffc24e4330d1
--- /dev/null
+++ b/packages/SettingsLib/DataStore/tests/AndroidManifest.xml
@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="utf-8"?>
+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+    package="com.android.settingslib.datastore.test">
+
+    <application android:debuggable="true" />
+</manifest>
diff --git a/packages/SettingsLib/DataStore/tests/config/robolectric.properties b/packages/SettingsLib/DataStore/tests/config/robolectric.properties
new file mode 100644
index 000000000000..fab7251d020b
--- /dev/null
+++ b/packages/SettingsLib/DataStore/tests/config/robolectric.properties
@@ -0,0 +1 @@
+sdk=NEWEST_SDK
diff --git a/packages/SettingsLib/DataStore/tests/src/com/android/settingslib/datastore/ObserverTest.kt b/packages/SettingsLib/DataStore/tests/src/com/android/settingslib/datastore/ObserverTest.kt
new file mode 100644
index 000000000000..bb791dc9a23c
--- /dev/null
+++ b/packages/SettingsLib/DataStore/tests/src/com/android/settingslib/datastore/ObserverTest.kt
@@ -0,0 +1,109 @@
+/*
+ * Copyright (C) 2024 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.settingslib.datastore
+
+import androidx.test.ext.junit.runners.AndroidJUnit4
+import com.google.common.truth.Truth.assertThat
+import com.google.common.util.concurrent.MoreExecutors
+import java.util.concurrent.Executor
+import java.util.concurrent.atomic.AtomicInteger
+import org.junit.Assert.assertThrows
+import org.junit.Rule
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.mockito.Mock
+import org.mockito.junit.MockitoJUnit
+import org.mockito.junit.MockitoRule
+import org.mockito.kotlin.any
+import org.mockito.kotlin.never
+import org.mockito.kotlin.reset
+import org.mockito.kotlin.verify
+
+@RunWith(AndroidJUnit4::class)
+class ObserverTest {
+    @get:Rule val mockitoRule: MockitoRule = MockitoJUnit.rule()
+
+    @Mock private lateinit var observer1: Observer
+
+    @Mock private lateinit var observer2: Observer
+
+    @Mock private lateinit var executor: Executor
+
+    private val observable = DataObservable()
+
+    @Test
+    fun addObserver_sameExecutor() {
+        observable.addObserver(observer1, executor)
+        observable.addObserver(observer1, executor)
+    }
+
+    @Test
+    fun addObserver_differentExecutor() {
+        observable.addObserver(observer1, executor)
+        assertThrows(IllegalStateException::class.java) {
+            observable.addObserver(observer1, MoreExecutors.directExecutor())
+        }
+    }
+
+    @Test
+    fun addObserver_weaklyReferenced() {
+        val counter = AtomicInteger()
+        var observer: Observer? = Observer { counter.incrementAndGet() }
+        observable.addObserver(observer!!, MoreExecutors.directExecutor())
+
+        observable.notifyChange(ChangeReason.UPDATE)
+        assertThat(counter.get()).isEqualTo(1)
+
+        // trigger GC, the observer callback should not be invoked
+        @Suppress("unused")
+        observer = null
+        System.gc()
+        System.runFinalization()
+
+        observable.notifyChange(ChangeReason.UPDATE)
+        assertThat(counter.get()).isEqualTo(1)
+    }
+
+    @Test
+    fun addObserver_notifyObservers_removeObserver() {
+        observable.addObserver(observer1, MoreExecutors.directExecutor())
+        observable.addObserver(observer2, executor)
+
+        observable.notifyChange(ChangeReason.DELETE)
+
+        verify(observer1).onChanged(ChangeReason.DELETE)
+        verify(observer2, never()).onChanged(any())
+        verify(executor).execute(any())
+
+        reset(observer1, executor)
+        observable.removeObserver(observer2)
+
+        observable.notifyChange(ChangeReason.UPDATE)
+        verify(observer1).onChanged(ChangeReason.UPDATE)
+        verify(executor, never()).execute(any())
+    }
+
+    @Test
+    fun notifyChange_addObserverWithinCallback() {
+        // ConcurrentModificationException is raised if it is not implemented correctly
+        observable.addObserver(
+            { observable.addObserver(observer1, executor) },
+            MoreExecutors.directExecutor()
+        )
+        observable.notifyChange(ChangeReason.UPDATE)
+    }
+}