test(NotificationUtils): Add tests for getting Twilio locale.

src/test/java/org/opentripplanner/middleware/utils/NotificationUtilsTest.java

@@ -0,0 +1,25 @@
+package org.opentripplanner.middleware.utils;
+
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+
+import static org.opentripplanner.middleware.utils.NotificationUtils.getTwilioLocale;
+
+/**
+ * Contains tests for the various notification utilities.
+ * Tests in this file do not require specific environment variables
+ * and do not contain end-to-end notification actions.
+ */
+class NotificationUtilsTest {
+    @Test
+    void canGetTwilioLocale() {
+        Assertions.assertEquals("en", getTwilioLocale("en"));
+        Assertions.assertEquals("en", getTwilioLocale("en-US"));
+        Assertions.assertEquals("en-GB", getTwilioLocale("en-GB"));
+        Assertions.assertEquals("fr", getTwilioLocale("fr-FR"));
+        Assertions.assertEquals("zh", getTwilioLocale("zh"));
+        Assertions.assertEquals("zh-HK", getTwilioLocale("zh-HK"));
+        Assertions.assertEquals("pt", getTwilioLocale("pt"));
+        Assertions.assertEquals("pt-BR", getTwilioLocale("pt-BR"));
+    }
+}