Trans doesn't call parseMissingKeyHandler

[igorsantos07]

🐛 Bug Report

Common t() calls with missing keys go through parseMissingKeyHandler if that's defined, but Trans doesn't, what feels like inconsistent/unexpected behavior.

To Reproduce

I created a single sandbox for multiple issues I'm reporting, so it's a bit bigger than expected, sorry :)

Expected behavior

Trans should also go through parseMissingKeyHandler? Or should it go somewhere else? I tried the missingInterpolationHandler, to no avail as well.

Your Environment

• runtime version: React 17, Chrome 91
• i18next version: 20.3.5 (installed last week?)
• react-i18next version: 11.11.4
• os: Linux

[jamuhl]

Never requested by devs to have that option -> so it's not added. We add features needed not just to be consistent with other calls -> Trans is a completely different beast (so there is no need to compare it to the API call of a simple t call).

So, yes...can be added - if someone needs it...but I won't add lines just to have them...save the bytes

[adrai]

fyi: seems it is not directly because of Trans, but because of the defaultValue usage...
i.e. i18n.t('keyWithDefault', 'some default')

this would fix it: https://github.com/i18next/i18next/blob/master/src/Translator.js#L273

[jamuhl]

@adrai lgtm

[adrai]

@igorsantos07 will be fixed in the next i18next version: i18next/i18next@da47faa

[kg-currenxie]

Hope its OK to borrow this thread (if not I can make a new issue)

We have a case like this

<Text text={t('.placeholder', { defaultValue: '' })} />

We have a generated form, where translation might, or might not be defined. So we'd like to just print nothing.

This commit/release (20.4.0) changes this behavior, and it will now look for the translation key '' instead.
Seems a bit strange to me, as its named defaultValue and not like defaultKey or fallbackKey, a feature already available if you use t(['key1', 'fallback'])

Is this intended? Feels more like a breaking change imo. If yes, how can i fall back to a string, and not a translation?
(We don't want to define translations with empty string values)

Update:
This is part of the config:

          parseMissingKeyHandler: (key: string) => {
            if (isDevelopment) {
              console.log(`Translation for key '${key}' is missing`)
            }
            return `[[MISSING KEY: ${key}]]`
          },

Update 2:
Documentation says

parseMissingKeyHandler:

function(key) { // return value to display }

[adrai]

@kg-currenxie Please create a reproducible example and open a new issue.