feat(i18n): added i18next for user interface translations (#432)

src/App/load-dayjs-locale.ts

@@ -0,0 +1,40 @@
+import dayjs from 'dayjs';
+import i18n from 'i18next';
+
+function getFallFackLanguage(): string | undefined {
+  const fallbackLanguage = i18n.options.fallbackLng;
+
+  if (Array.isArray(fallbackLanguage)) {
+    return fallbackLanguage[0];
+  }
+
+  if (typeof fallbackLanguage === 'string') {
+    return fallbackLanguage;
+  }
+
+  return undefined;
+}
+
+function loadDayJSLocale() {
+  const fallbackLanguage = getFallFackLanguage();
+  const locale = i18n.language || fallbackLanguage;
+
+  // dayjs loades en-US by default
+  if (!locale || locale === 'en-US') {
+    return;
+  }
+
+  switch (locale.toLowerCase()) {
+    // At the moment we only support pt-BR, please see: i18n/translations/*
+    case 'pt-br':
+      {
+        require('dayjs/locale/pt-br');
+        dayjs.locale('pt-br');
+      }
+      break;
+    default:
+      break;
+  }
+}
+
+export default loadDayJSLocale;