Falllback locale not working when the key path is not incomplete exist in current locale data

[everyx]

Environment

• Operating System: Linux
• Node Version: v18.18.0
• Nuxt Version: 3.8.0
• CLI Version: 3.9.1
• Nitro Version: 2.7.2
• Package Manager: [email protected]
• Builder: -
• User Config: modules, i18n
• Runtime Modules: @nuxtjs/[email protected]
• Build Modules: -

Reproduction

https://stackblitz.com/edit/bobbiegoede-nuxt-i18n-starter-dwhr3q?file=pages%2Findex.vue

Describe the bug

When I set default en locale message as below:

{
	"deep": {
		"hello": {
			"world": "Test"
		}
	}
}

and another es locale message as below:

{
	"deep": {
		"hello":  null
	}
}

I use tm and rt to get and display this message

<script lang="ts" setup>
const { tm, rt } = useI18n({ useScope: 'global' });
const test = tm('deep.hello.world');
</script>
<template>
  <div>
    <h1>Nuxt I18n Starter - {{ $t('hello') }}!</h1>
    <p>{{ rt(test) }}</p>
  </div>
</template>

Then if I switch locale from en to es, I get error last is null and can not fallback to 'en' message.

I also tried vue-i18n and there was no such problem. For an example, see https://stackblitz.com/edit/vitejs-vite-asteuw?file=src%2FApp.vue

Additional context

No response

Logs

No response

[BobbieGoede]

This doesn't work in vue-i18n either, it seems like your vue-i18n reproduction silently fails. If you set the locale to 'ja' and the fallbackLocale to 'en' it will error on load. I have edited your reproduction to demonstrate here, if you expect this behavior to work I suggest opening an issue on repo of vue-i18n.

[everyx]

@BobbieGoede just created a issue in upstream, thanks intlify/vue-i18n#1702