Trans only interpolates defaultVariables if values or components is present

[hubgit]

🐛 Bug Report

I was surprised to find that the Trans component does not interpolate values from defaultVariables when only the translation key is provided.

To Reproduce

https://codesandbox.io/p/sandbox/i18-next-trans-default-variables-tq3xmv

import i18n from 'i18next'
import { initReactI18next, Trans } from 'react-i18next'

i18n.use(initReactI18next).init({
  lng: 'en',
  interpolation: {
    defaultVariables: {
      name: 'Bob',
    },
  },
  resources: {
    en: {
      translation: {
        test: 'My name is {{name}}.',
      },
    },
  },
})

export const App = () => (
  <div className="App">
    <div>
      <Trans i18nKey="test" />
    </div>
    <div>
      <Trans i18nKey="test" components={{}} />
    </div>
    <div>
      <Trans i18nKey="test" values={{}} />
    </div>
  </div>
)

Expected behavior

<Trans i18nKey="test" /> should interpolate default variables into the translation template with key test.

Your Environment

• runtime version: Node v18, Chrome v117

• i18next version: 23.5.1

• react-i18next version: 13.2.2

• os: macOS

• refs Can't use default variables in Translate component without values prop #1375

• refs Trans escapes html tags in defaultVariables if values is not specified or interpolation prefix and suffix are not specified in tOptions #1515

[hubgit]

The workaround is to use t('test') instead of <Trans i18nKey="test"/>.

[adrai]

That's a new feature... coming with v13.3.0