Why are JSON arrays not supported?

[aartoni]

I'm moving this question here since, the original issue (#1878) got closed automatically as stale.

Link to page

https://next-intl.dev/docs/usage/messages#arrays-of-messages

Describe the problem

I know this has been discussed before, but most related issues seem to reference older conversations I can't track down. Could someone summarize the key points or link to the relevant threads? Should we add the produced summary to the documentation itself?

[amannn]

Thanks for the question! I haven't found a compelling argument for arrays yet, to be honest.

However they come with limitations:

1. They'd need to share variables (see e.g. an older expandable section from the docs)
2. Their usage can sometimes be hard to statically analyze (see e.g. Handle dynamic keys in next-intl lingualdev/i18n-check#51, also for Automatic tree-shaking of messages #1 we'll need static analysis)

It seems to me like the use cases for arrays can already be handled well with the current feature set, while avoiding limitations to some degree.

I've also considered to recommend against programmatic invocations in general, also something like this:

t(`${key}.title`)

The benefit is really to have improved static analysis. So the example from the docs would become either:

const stats = [{
  title: t('yearsOfService.title'),
  description: t('yearsOfService.title')
}, {
  title: t('happyClients.title'),
  description: t('happyClients.title')
}]

… or:

<ul>
  <CompanyStatsItem title={t('yearsOfService.title')} description={t('yearsOfService.title')} />
  <CompanyStatsItem title={t('happyClients.title')} description={t('happyClients.title')} />
</ul>

In both cases, it's now also easy to include exceptions, e.g. providing different variables:

<ul>
  <CompanyStatsItem title={t('yearsOfService.title', {numYears: 12})} description={t('yearsOfService.title')} />
  <CompanyStatsItem title={t('happyClients.title', {numClient: 3000})} description={t('happyClients.title')} />
</ul>

Also, they are fully statically analyzable.

It seems to me like arrays would introduce complexity for next-intl, without really being a "good" solution that I would recommend.

Do you have a use case that would significantly benefit if arrays were allowed in messages?