Merge pull request Expensify#66154 from callstack-internal/performance/translation-improvement

fix: improve performance for translation

Author: roryabraham

src/libs/Localize/index.ts

@@ -26,6 +26,7 @@ Onyx.connect({
 // Note: This has to be initialized inside a function and not at the top level of the file, because Intl is polyfilled,
 // and if React Native executes this code upon import, then the polyfill will not be available yet and it will barf
 let CONJUNCTION_LIST_FORMATS_FOR_LOCALES: Record<string, Intl.ListFormat>;
+
 function init() {
     CONJUNCTION_LIST_FORMATS_FOR_LOCALES = Object.values(CONST.LOCALES).reduce((memo: Record<string, Intl.ListFormat>, locale) => {
         // eslint-disable-next-line no-param-reassign
@@ -34,6 +35,10 @@ function init() {
     }, {});
 }
 
+// Memoized function to create PluralRules instances
+const createPluralRules = (locale: Locale): Intl.PluralRules => new Intl.PluralRules(locale);
+const memoizedCreatePluralRules = memoize(createPluralRules);
+
 /**
  * Helper function to get the translated string for given
  * locale and phrase. This function is used to avoid
@@ -70,7 +75,7 @@ function getTranslatedPhrase<TKey extends TranslationPaths>(language: Locale, ph
                 throw new Error(`Invalid plural form for '${phraseKey}'`);
             }
 
-            const pluralRule = new Intl.PluralRules(language).select(phraseObject.count);
+            const pluralRule = memoizedCreatePluralRules(language).select(phraseObject.count);
 
             const pluralResult = translateResult[pluralRule];
             if (pluralResult) {