Translation function return type DefaultTFuncReturn makes React Native errors

[azuken]

💥 Regression Report

On React Native, we have some functions which ask for a string | undefined type, for example Alert.alert(), or @react-navigation component attributes.
Since DefaultTFuncReturn returns a string | null value, Typescript raise a type assignation error (TS2322).

TS2322: Type 'DefaultTFuncReturn' is not assignable to type 'string | undefined'.

Can be solved with ?? undefined operator, but it is dirty and very redundant.

Last working version

Worked up to version: 22.0.4

Stopped working in version: 22.0.5

To Reproduce

Steps to reproduce the behavior:

Alert.alert(
      t('home.accountRequiredTitle'),
      t('home.accountRequiredDescription'),
      [
        {
          text: t('home.signIn'),
          onPress: () => navigation.navigate('SignIn')
        },
        {
          text: t('home.signUp'),
          onPress: () => navigation.navigate('SignUp')
        }
      ],
      { cancelable: true }
    );

Expected behavior

No Typescript error.

Your Environment

• runtime version: node v18
• i18next version: 22.0.5
• os: Mac

[adrai]

This may help: https://www.i18next.com/overview/typescript#argument-of-type-defaulttfuncreturn-is-not-assignable-to-parameter-of-type-xyz

[adrai]

fyi: #1865
i18next/react-i18next#1559, i18next/react-i18next#1576, i18next/react-i18next#1574

[azuken]

Works like a charm! Thanks.

Didn't know such option existed, sorry for the inconvenience!