Integrate system language filtering functionality

Filter system languages based on the configuration provided via
the corresponding system property.

Bug: 154133013
Test: manual; atest LocalizationTest
Change-Id: I7e4694f4b381ab81d0e8ceab97bad68bb266aaee

1 files changed, 118 insertions, 0 deletions

diff --git a/tests/LocalizationTest/java/com/android/internal/app/LocalizationTest.kt b/tests/LocalizationTest/java/com/android/internal/app/LocalizationTest.kt
new file mode 100644
index 000000000000..22ea97167326
--- /dev/null
+++ b/tests/LocalizationTest/java/com/android/internal/app/LocalizationTest.kt
@@ -0,0 +1,118 @@
+/*
+ * Copyright (C) 2020 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.android.internal.app
+
+import android.os.SystemProperties
+import androidx.test.ext.junit.runners.AndroidJUnit4
+import androidx.test.platform.app.InstrumentationRegistry
+import com.android.dx.mockito.inline.extended.ExtendedMockito.doReturn
+import com.android.dx.mockito.inline.extended.ExtendedMockito.mockitoSession
+import com.android.internal.R
+import com.android.internal.app.LocalePicker
+import com.google.common.truth.Truth.assertThat
+import org.junit.Before
+import org.junit.After
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.mockito.ArgumentMatchers.eq
+import org.mockito.MockitoSession
+
+@RunWith(AndroidJUnit4::class)
+class LocalizationTest {
+    private val mContext = InstrumentationRegistry.getInstrumentation().context
+    private val mUnfilteredLocales =
+            mContext.getResources().getStringArray(R.array.supported_locales)
+
+    private lateinit var mMockitoSession: MockitoSession
+
+    @Before
+    fun setUp() {
+        mMockitoSession = mockitoSession()
+                .initMocks(this)
+                .spyStatic(SystemProperties::class.java)
+                .startMocking()
+    }
+
+    @After
+    fun tearDown() {
+        mMockitoSession.finishMocking()
+    }
+
+    @Test
+    fun testGetSupportedLocales_noFilter() {
+        // Filter not set.
+        setTestLocaleFilter(null)
+
+        val locales1 = LocalePicker.getSupportedLocales(mContext)
+
+        assertThat(locales1).isEqualTo(mUnfilteredLocales)
+
+        // Empty filter.
+        setTestLocaleFilter("")
+
+        val locales2 = LocalePicker.getSupportedLocales(mContext)
+
+        assertThat(locales2).isEqualTo(mUnfilteredLocales)
+    }
+
+    @Test
+    fun testGetSupportedLocales_invalidFilter() {
+        setTestLocaleFilter("**")
+
+        val locales = LocalePicker.getSupportedLocales(mContext)
+
+        assertThat(locales).isEqualTo(mUnfilteredLocales)
+    }
+
+    @Test
+    fun testGetSupportedLocales_inclusiveFilter() {
+        setTestLocaleFilter("^(de-AT|de-DE|en|ru).*")
+
+        val locales = LocalePicker.getSupportedLocales(mContext)
+
+        assertThat(locales).isEqualTo(
+                mUnfilteredLocales
+                        .filter { it.startsWithAnyOf("de-AT", "de-DE", "en", "ru") }
+                        .toTypedArray()
+        )
+    }
+
+    @Test
+    fun testGetSupportedLocales_exclusiveFilter() {
+        setTestLocaleFilter("^(?!de-IT|es|fr).*")
+
+        val locales = LocalePicker.getSupportedLocales(mContext)
+
+        assertThat(locales).isEqualTo(
+                mUnfilteredLocales
+                        .filter { !it.startsWithAnyOf("de-IT", "es", "fr") }
+                        .toTypedArray()
+        )
+    }
+
+    private fun setTestLocaleFilter(localeFilter: String?) {
+        doReturn(localeFilter).`when` { SystemProperties.get(eq("ro.localization.locale_filter")) }
+    }
+
+    private fun String.startsWithAnyOf(vararg prefixes: String): Boolean {
+        prefixes.forEach {
+            if (startsWith(it)) return true
+        }
+
+        return false
+    }
+}