[Settings] Add test case for new LocalePicker page - suggested language

Bug: 396285228
Test: atest
Test: atest SettingsRoboTests:com.android.settings.localepicker.SystemLocaleSuggestedListPreferenceControllerTest
Test: atest SettingsUnitTests:com.android.settings.localepicker.SystemLocaleSuggestedListPreferenceControllerTest
Flag: EXEMPT refactor
Change-Id: I70d731b50775bf45ae0d73e4da9ea78dfcd3826c

tests/unit/src/com/android/settings/localepicker/SystemLocaleSuggestedListPreferenceControllerTest.java

@@ -0,0 +1,111 @@
+/**
+ * Copyright (C) 2025 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.localepicker;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.assertFalse;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.spy;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+import android.app.Activity;
+import android.content.Context;
+import android.os.Looper;
+
+import com.android.internal.app.LocaleStore;
+import com.android.internal.app.SystemLocaleCollector;
+
+import androidx.preference.Preference;
+import androidx.preference.PreferenceCategory;
+import androidx.preference.PreferenceManager;
+import androidx.preference.PreferenceScreen;
+import androidx.test.core.app.ApplicationProvider;
+import androidx.test.ext.junit.runners.AndroidJUnit4;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.MockitoAnnotations;
+
+import java.util.Locale;
+import java.util.Set;
+
+@RunWith(AndroidJUnit4.class)
+public class SystemLocaleSuggestedListPreferenceControllerTest {
+    private static final String KEY_CATEGORY_SYSTEM_SUGGESTED_LIST =
+            "system_language_suggested_category";
+    private static final String KEY_SUGGESTED = "system_locale_suggested_list";
+
+    private Context mContext;
+    private PreferenceManager mPreferenceManager;
+    private PreferenceCategory mPreferenceCategory;
+    private PreferenceScreen mPreferenceScreen;
+    private Preference mSuggestedPreference;
+    private SystemLocaleSuggestedListPreferenceController mController;
+    private Set<LocaleStore.LocaleInfo> mLocaleList;
+
+    @Before
+    public void setUp() throws Exception {
+        MockitoAnnotations.initMocks(this);
+        mContext = spy(ApplicationProvider.getApplicationContext());
+
+        if (Looper.myLooper() == null) {
+            Looper.prepare();
+        }
+
+        SystemLocaleCollector systemLocaleCollector = new SystemLocaleCollector(mContext, null);
+        mLocaleList = systemLocaleCollector.getSupportedLocaleList(null, false, false);
+        mPreferenceManager = new PreferenceManager(mContext);
+        mPreferenceScreen = mPreferenceManager.createPreferenceScreen(mContext);
+        mPreferenceCategory = new PreferenceCategory(mContext);
+        mPreferenceCategory.setKey(KEY_CATEGORY_SYSTEM_SUGGESTED_LIST);
+        mPreferenceScreen.addPreference(mPreferenceCategory);
+        mController = new SystemLocaleSuggestedListPreferenceController(mContext, KEY_SUGGESTED);
+        mController.displayPreference(mPreferenceScreen);
+    }
+
+    @Test
+    public void displayPreference_suggestedLocaleShouldBeInSuggestedCategory() {
+        int count = 0;
+        for (LocaleStore.LocaleInfo localeInfo : mLocaleList) {
+            if (localeInfo.isSuggested()) {
+                count++;
+            }
+        }
+
+        assertThat(mPreferenceCategory.getPreferenceCount()).isEqualTo(count);
+    }
+
+    @Test
+    public void displayPreference_hasSuggestedPreference_categoryIsVisible() {
+        int count = 0;
+        for (LocaleStore.LocaleInfo localeInfo : mLocaleList) {
+            if (localeInfo.isSuggested()) {
+                count++;
+            }
+        }
+
+        if (count > 0) {
+            assertTrue(mPreferenceCategory.isVisible());
+        } else {
+            assertFalse(mPreferenceCategory.isVisible());
+        }
+    }
+}