Get i18next to fallback to 'NO TRANSLATION'

Question

The i18next translation library by default seems to fallback to the translation key if no translation was found for the key, e.g.

// No translation defined for CANCEL yet
i18next.t('CANCEL') // Returns 'CANCEL'

If no translation is found for the key, I would prefer to fallback to a distinctive message that makes it obvious that we've missed a translation or mistyped a translation key. Preferably mentioning the key in the message e.g.

i18next.t('CANCEL') // Returns 'No translation found for "CANCEL"'

Some sort of fallback callback function would be ideal because then we could also log to console/remote service any missing translations.

How can I achieve something like this using the i18next library?

Answer 1

So it turns out i18next accepts a handler in the options, while initializing it lets you set the value for the missing keys.

i18n.init({
    ...
    
    parseMissingKeyHandler: (key: string) => {
        return `No translation found for "${key}"`;
    }
})