add regression test for optional chaining issue (#1856)

* add regression test for optional chaining issue

* avoid exception when passing bindI18n: false

Author: bjoerge

src/useTranslation.js

@@ -132,7 +132,7 @@ export const useTranslation = (ns, props = {}) => {
     // unbinding on unmount
     return () => {
       isMounted.current = false;
-      if (i18n) bindI18n?.split(' ').forEach((e) => i18n.off(e, boundReset));
+      if (i18n && bindI18n) bindI18n?.split(' ').forEach((e) => i18n.off(e, boundReset));
       if (bindI18nStore && i18n)
         bindI18nStore.split(' ').forEach((e) => i18n.store.off(e, boundReset));
     };

src/utils.js

@@ -72,7 +72,8 @@ export const hasLoadedNamespace = (ns, i18n, options = {}) => {
     lng: options.lng,
     precheck: (i18nInstance, loadNotPending) => {
       if (
-        options.bindI18n?.indexOf('languageChanging') > -1 &&
+        options.bindI18n &&
+        options.bindI18n.indexOf('languageChanging') > -1 &&
         i18nInstance.services.backendConnector.backend &&
         i18nInstance.isLanguageChangingTo &&
         !loadNotPending(i18nInstance.isLanguageChangingTo, ns)

test/useTranslation.spec.jsx

@@ -186,6 +186,15 @@ describe('useTranslation', () => {
       <I18nextProvider i18n={i18n}>{children}</I18nextProvider>
     );
 
+    it('should not fail when passing bindI18n: false or undefined', () => {
+      expect(() =>
+        renderHook(() => useTranslation('translation', { bindI18n: false })),
+      ).to.not.throw();
+      expect(() =>
+        renderHook(() => useTranslation('translation', { bindI18n: undefined })),
+      ).to.not.throw();
+    });
+
     it('should render correct content', () => {
       const { result: resultNoLng } = renderHook(() => useTranslation('translation'), {
         wrapper,