Add ICU4J dependency + initial tests

org.hl7.fhir.utilities/pom.xml

@@ -80,6 +80,12 @@
             <optional>true</optional>
         </dependency>
 
+        <dependency>
+            <groupId>com.ibm.icu</groupId>
+            <artifactId>icu4j</artifactId>
+            <version>72.1</version>
+        </dependency>
+
         <!-- JUnit Jupiter -->
         <dependency>
             <groupId>org.junit.jupiter</groupId>

org.hl7.fhir.utilities/src/test/java/org/hl7/fhir/utilities/i18n/I18nBaseTest.java

@@ -1,5 +1,6 @@
 package org.hl7.fhir.utilities.i18n;
 
+import com.ibm.icu.text.PluralRules;
 import org.junit.jupiter.api.Assertions;
 import org.junit.jupiter.api.DisplayName;
 import org.junit.jupiter.api.Test;
@@ -12,6 +13,11 @@ import java.nio.charset.StandardCharsets;
 import java.text.MessageFormat;
 import java.util.*;
 
+import static org.hamcrest.CoreMatchers.containsString;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
 class I18nBaseTest {
 
   public static final String BAD_STRING_ARG = "THIS_DOES_NOT_EXIST";
@@ -40,6 +46,38 @@ class I18nBaseTest {
     Assertions.assertEquals(form.format(testArgs), result);
   }
 
+  @Test
+  @DisplayName("Test pluralization works without initializing Locale.")
+  void testFormatMessagePluralWithoutInitLocale() {
+    I18nTestClass testClass = new I18nTestClass();
+    
+    //Answer value must be of the type {1}
+    String resultOne = testClass.formatMessagePL(1, I18nConstants.QUESTIONNAIRE_QR_ITEM_WRONGTYPE_PLURAL);
+    assertThat(resultOne, containsString("be of the type"));
+
+    //Answer value must be one of the {0} types {1}
+    String resultMany = testClass.formatMessagePL(3, I18nConstants.QUESTIONNAIRE_QR_ITEM_WRONGTYPE_PLURAL);
+    assertThat(resultMany, containsString("one of the 3 types "));
+
+  }
+
+  @Test
+  @DisplayName("Test pluralization works without initializing Locale.")
+  void testFormatMessagePluralWithInitLocale() {
+    I18nTestClass testClass = new I18nTestClass();
+    //ResourceBundle loadedBundle = ResourceBundle.getBundle("Messages", Locale.GERMAN);
+
+    testClass.setLocale(Locale.GERMAN);
+    //Answer value muss einer der Typen {1} sein
+    String resultOne = testClass.formatMessagePL(1, I18nConstants.QUESTIONNAIRE_QR_ITEM_WRONGTYPE_PLURAL);
+    assertThat(resultOne, containsString("Answer value muss einer der Typen {1} sein"));
+
+    //?
+    String resultMany = testClass.formatMessagePL(3, I18nConstants.QUESTIONNAIRE_QR_ITEM_WRONGTYPE_PLURAL);
+    assertThat(resultMany, containsString("one of the 3 types "));
+
+  }
+
   @Test
   @DisplayName("Assert no string modification is done when no match is found.")
   void testFormatMessageForNonExistentMessage() {
@@ -68,7 +106,7 @@ class I18nBaseTest {
         String line;
         while ((line = reader.readLine()) != null) {
 //          System.out.println("Searching for umlauts -> " + line);
-          Assertions.assertFalse(stringContainsItemFromList(line, UMLAUTS));
+          assertFalse(stringContainsItemFromList(line, UMLAUTS));
         }
     } catch (IOException e) {
       e.printStackTrace();
@@ -80,4 +118,20 @@ class I18nBaseTest {
   public static boolean stringContainsItemFromList(String inputStr, String[] items) {
     return Arrays.stream(items).anyMatch(inputStr::contains);
   }
+
+  @Test
+  void pluralKeysCompleteAndValid() {
+    ResourceBundle loadedBundle = ResourceBundle.getBundle("Messages", Locale.GERMAN);
+    PluralRules pluralRules = PluralRules.forLocale(Locale.GERMANY);
+    for (String key : loadedBundle.keySet()) {
+       String[] keyComponent = key.split("_");
+
+       assertFalse(keyComponent[keyComponent.length - 1].equalsIgnoreCase("PLURAL"), "Invalid use of PLURAL keyword for key: " + key);
+       if (keyComponent.length > 2
+        && keyComponent[keyComponent.length - 2].equalsIgnoreCase("PLURAL")) {
+          assertTrue(pluralRules.getKeywords().contains(keyComponent[keyComponent.length - 1]));
+       }
+    }
+  }
+
 }

org.hl7.fhir.utilities/src/test/java/org/hl7/fhir/utilities/i18n/ICU4JTests.java

@@ -0,0 +1,52 @@
+package org.hl7.fhir.utilities.i18n;
+
+import com.ibm.icu.text.PluralRules;
+import org.junit.jupiter.api.Test;
+
+import java.util.Arrays;
+import java.util.HashSet;
+import java.util.Locale;
+import java.util.Set;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+public class ICU4JTests {
+
+  static final String[] EN_KEYWORDS = {
+    PluralRules.KEYWORD_ONE,
+    PluralRules.KEYWORD_OTHER
+  };
+
+  @Test
+  void getEnLocalePlurals() {
+    final Set<String> keywords = getPluralKeywords(Locale.ENGLISH);
+    assertEquals(keywords, new HashSet<String>(Arrays.asList(EN_KEYWORDS)));
+  }
+
+  static final String[] DE_KEYWORDS = {
+    PluralRules.KEYWORD_ONE,
+    PluralRules.KEYWORD_OTHER
+  };
+
+  @Test
+  void getDeLocalePlurals() {
+    final Set<String> keywords = getPluralKeywords(Locale.GERMAN);
+    assertEquals(keywords, new HashSet<String>(Arrays.asList(DE_KEYWORDS)));
+  }
+
+  static final String[] NL_KEYWORDS = {
+    PluralRules.KEYWORD_ONE,
+    PluralRules.KEYWORD_OTHER
+  };
+
+  @Test
+  void getNlLocalePlurals() {
+    final Set<String> keywords = getPluralKeywords(Locale.forLanguageTag("nl"));
+    assertEquals(keywords, new HashSet<String>(Arrays.asList(NL_KEYWORDS)));
+  }
+
+  private static Set<String> getPluralKeywords(Locale locale) {
+    final PluralRules pluralRules = PluralRules.forLocale(locale);
+    return pluralRules.getKeywords();
+  }
+}