Adds new test for ApplicationState sorting function.

Test: atest com.android.settingslib.applications.ApplicationStateComponentTest
Bug: 184814907
Change-Id: Ie6fd2d9d58a8dac64ad1408f1d3122b7d74ae7a3

tests/componenttests/src/com/android/settingslib/applications/ApplicationStateComponentTest.java

@@ -0,0 +1,100 @@
+/*
+ * Copyright (C) 2021 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.applications;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import android.content.Context;
+import android.content.Intent;
+import android.content.pm.ApplicationInfo;
+
+import androidx.test.core.app.ActivityScenario;
+import androidx.test.ext.junit.rules.ActivityScenarioRule;
+import androidx.test.ext.junit.runners.AndroidJUnit4;
+import androidx.test.filters.SmallTest;
+
+import com.android.settings.Settings;
+
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+import java.util.UUID;
+
+@RunWith(AndroidJUnit4.class)
+@SmallTest
+public class ApplicationStateComponentTest {
+    private static final String TAG =
+            ApplicationStateComponentTest.class.getSimpleName();
+    private Context mRuntimeApplication;
+    private ApplicationsState mApplicationsState;
+
+    @Rule
+    public ActivityScenarioRule<Settings.ManageApplicationsActivity> rule =
+            new ActivityScenarioRule<>(
+                    new Intent(
+                            android.provider.Settings.ACTION_MANAGE_ALL_APPLICATIONS_SETTINGS)
+                            .setFlags(Intent.FLAG_ACTIVITY_NEW_TASK));
+
+    private ApplicationsState.AppEntry createAppEntry(String label, String packageName, int id) {
+        ApplicationInfo appInfo = createApplicationInfo(packageName, id);
+        ApplicationsState.AppEntry appEntry = new ApplicationsState.AppEntry(mRuntimeApplication,
+                appInfo, id);
+        appEntry.label = label;
+        appEntry.mounted = true;
+        return appEntry;
+    }
+
+    private ApplicationInfo createApplicationInfo(String packageName, int uid) {
+        ApplicationInfo appInfo = new ApplicationInfo();
+        appInfo.sourceDir = "foo";
+        appInfo.flags |= ApplicationInfo.FLAG_INSTALLED;
+        appInfo.storageUuid = UUID.randomUUID();
+        appInfo.packageName = packageName;
+        appInfo.uid = uid;
+        return appInfo;
+    }
+
+    @Test
+    public void test_all_apps_sorting_alpha() {
+        // TODO: Potential unit test candidate.
+        // To test all app list has sorted alphabetical, only need to verify sort function.
+        // This case focus on logic in sort function, and ignore origin locale sorting rule by Java.
+
+        ActivityScenario scenario = rule.getScenario();
+
+        scenario.onActivity(activity -> {
+            mRuntimeApplication = activity.getApplication();
+            mApplicationsState = ApplicationsState.getInstance(activity.getApplication());
+
+            ApplicationsState.AppEntry entry1 = createAppEntry("Info01", "Package1", 0);
+            ApplicationsState.AppEntry entry2 = createAppEntry("Info02", "Package1", 0);
+            ApplicationsState.AppEntry entry3 = createAppEntry("Info01", "Package2", 0);
+            ApplicationsState.AppEntry entry4 = createAppEntry("Info02", "Package2", 0);
+            ApplicationsState.AppEntry entry5 = createAppEntry("Info02", "Package2", 1);
+            assertThat(ApplicationsState.ALPHA_COMPARATOR.compare(entry1, entry2)).isEqualTo(-1);
+            assertThat(ApplicationsState.ALPHA_COMPARATOR.compare(entry2, entry3)).isEqualTo(1);
+            assertThat(ApplicationsState.ALPHA_COMPARATOR.compare(entry3, entry2)).isEqualTo(-1);
+            assertThat(ApplicationsState.ALPHA_COMPARATOR.compare(entry3, entry3)).isEqualTo(0);
+            assertThat(ApplicationsState.ALPHA_COMPARATOR.compare(entry1, entry3)).isEqualTo(-1);
+            assertThat(ApplicationsState.ALPHA_COMPARATOR.compare(entry4, entry5)).isEqualTo(-1);
+            assertThat(ApplicationsState.ALPHA_COMPARATOR.compare(entry5, entry3)).isEqualTo(1);
+
+        });
+
+    }
+}