Update LanguageDetectorAsyncModule

[daomtthuan]

Add return type Promise<void> for LanguageDetectorAsyncModule

[coveralls]

Coverage remained the same at 91.436% when pulling 615194b on daomtthuan:master into 913190d on i18next:master.

[daomtthuan]

@adrai
Why do init, detect and cacheUserLanguage not return promises in the module LanguageDetectorAsyncModule,
although it is async: true?

In this case
When use LanguageDetector with AsyncStorage

  import AsyncStorage from '@react-native-async-storage/async-storage'

  const LANGUAGE_KEY = 'i18n.language';

  const languageDetector: LanguageDetectorAsyncModule = {
    type: 'languageDetector',
    async: true,
    init: () => {
      // Do nothing.
    },
    detect: async (setLanguage) => {
      try {
        const language = await AsyncStorage.getItem(LANGUAGE_KEY);

        setLanguage(language ?? 'en');
      } catch (exception) {
        console.error(exception);
      }
    },
    cacheUserLanguage: async (language) => {
      try {
        await AsyncStorage.setItem(LANGUAGE_KEY, language);
      } catch (exception) {
        console.error(exception);
      }
    },
  };

because use async/await, LanguageDetector is LanguageDetectorAsyncModule, not LanguageDetectorModule.
That is the reason I add return type promise for LanguageDetectorAsyncModule

[adrai]

Because the interface looks like this: https://www.i18next.com/misc/creating-own-plugins#languagedetector

[daomtthuan]

@adrai
So, can not use async/await for detect and cacheUserLanguage?
I know it can be like this:

  import AsyncStorage from '@react-native-async-storage/async-storage'

  const LANGUAGE_KEY = 'i18n.language';

  const languageDetector: LanguageDetectorAsyncModule = {
    type: 'languageDetector',
    async: true,
    init: () => {
      // Do nothing.
    },
    detect: (setLanguage) => {
      AsyncStorage.getItem(LANGUAGE_KEY)
        .then((language) => setLanguage(language ?? 'en'))
        .catch((exception) => console.error(exception));
    },
    cacheUserLanguage: (language) => {
      AsyncStorage.setItem(LANGUAGE_KEY, language).catch((exception) => console.error(exception));
    },
  };

I don't like to use then/catch with promise
Do you have any ideas for this?

[adrai]

This is sufficient:

import AsyncStorage from '@react-native-async-storage/async-storage'

  const LANGUAGE_KEY = 'i18n.language';

  const languageDetector: LanguageDetectorAsyncModule = {
    type: 'languageDetector',
    async: true,
    init: () => {},
    detect: (setLanguage) => {
      AsyncStorage.getItem(LANGUAGE_KEY)
        .then((language) => setLanguage(language ?? 'en'));
    },
    cacheUserLanguage: (language) => {
      AsyncStorage.setItem(LANGUAGE_KEY, language)
    }
  };

That's how the interface of i18next is defined since the beginning...

I'll check later, if at least we can accept a promise for the detect function.... will let you know.

[adrai]

ok, with v22.3.0 you can now do this:

  import AsyncStorage from '@react-native-async-storage/async-storage'

  const LANGUAGE_KEY = 'i18n.language';

  const languageDetector: LanguageDetectorAsyncModule = {
    type: 'languageDetector',
    async: true,
    detect: () => AsyncStorage.getItem(LANGUAGE_KEY),
    cacheUserLanguage: (language) => AsyncStorage.setItem(LANGUAGE_KEY, language)
  };

also updated the docs:

[daomtthuan]

Thank you <3