How to disable getBestMatchFromCodes?

[yoroshikun]

🐛 Bug Report

When consuming this library to detect language (we currently use path) it will auto extrapolate the language code very eagerly. We need a way to disable that. Unless we are missing something in the config code.

Related line.

i18next-browser-languageDetector/src/index.js

Line 77 in 9ad3019

if (this.services.languageUtils.getBestMatchFromCodes) return detected; // new i18next v19.5.0

To Reproduce

With the config set to below

  supportedLngs: ['ja', 'en', ...],
  ...
          detection: {
            order: ['path'],
          },

navigating to {base}/e will infer en <- incorrect assumption
navigating to {base}/c will infer cimode <- not supported at all
and so on.

Expected behavior

No assumption to be made on the intended language, expecially in path mode.

navigating to {base}/e will not infer en falling back to the default language set
same for c etc.

Your Environment

• runtime version: i.e. node 20.10
• i18next version: i.e. 21.10.0
• os: Mac,
• any other relevant information

[adrai]

try i18next v23.10.1 and set the fallbackLng option to your desired fallback language (ja or en)

[adrai]

if this does not help, you can add your own language detector (https://github.com/i18next/i18next-browser-languageDetector?tab=readme-ov-file#adding-own-detection-functionality) that validates for correct language codes...
Or provide a PR with an optional option for to do this language code validation here: https://github.com/i18next/i18next-browser-languageDetector/blob/master/src/index.js#L76

[yoroshikun]

Thank you so much for this change, I have confirmed that this correctly defaults to the fallback lang instead of inferring non supported languages