Add TwilioVerifySender

service/src/test/java/org/whispersystems/textsecuregcm/tests/util/LocaleTest.java

@@ -0,0 +1,45 @@
+package org.whispersystems.textsecuregcm.tests.util;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import java.util.Collections;
+import java.util.List;
+import java.util.Locale.LanguageRange;
+import java.util.Optional;
+import java.util.Set;
+import java.util.stream.Stream;
+import javax.annotation.Nullable;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.Arguments;
+import org.junit.jupiter.params.provider.MethodSource;
+import org.whispersystems.textsecuregcm.util.Util;
+
+class LocaleTest {
+
+  private static final Set<String> SUPPORTED_LOCALES = Set.of("es", "en", "zh", "zh-HK");
+
+  @ParameterizedTest
+  @MethodSource
+  void testFindBestLocale(@Nullable final String languageRange, @Nullable final String expectedLocale) {
+
+    final List<LanguageRange> languageRanges = Optional.ofNullable(languageRange)
+        .map(LanguageRange::parse)
+        .orElse(Collections.emptyList());
+
+    assertEquals(Optional.ofNullable(expectedLocale), Util.findBestLocale(languageRanges, SUPPORTED_LOCALES));
+  }
+
+  static Stream<Arguments> testFindBestLocale() {
+    return Stream.of(
+        // languageRange, expectedLocale
+        Arguments.of("en-US, fr", "en"),
+        Arguments.of("es-ES", "es"),
+        Arguments.of("zh-Hant-HK, zh-HK", "zh"),
+        // zh-HK is supported, but Locale#lookup truncates from the end, per RFC-4647
+        Arguments.of("zh-Hant-HK", "zh"),
+        Arguments.of("zh-HK", "zh-HK"),
+        Arguments.of("de", null),
+        Arguments.of(null, null)
+    );
+  }
+}