feat: add extendComponentMeta

[romhml]

This is a quick PoC to discuss about the introduction of a extendComponentMeta function to allow users to pass arbitrary objects into component meta data like so:

<script setup>
extendComponentMeta({ hello: 'world' })
</script>

This would allow library authors to pass additional component data to implement devtools more easily.

We might consider implementing a vite plugin to remove the function from the bundle after we parsed it. It might also make more sense to include it in vue-component-meta since this is where most of the parsing is done.

[farnabaz]

Thank you @romhml
I'm merging this to test on the package and we can iterate on it in next releases

[romhml]

I ended up implementing a slightly better version than this here if you want to have a look:
https://github.com/nuxt/ui/pull/2196/files#diff-4795a876424cc5bbc19726d11b6ff10eb6002253ad1d74dea1b1f7b47822e196R37

[adamdehaven]

Is extendComponentMeta stable enough for a long-term Production project?

I'd like to implement some custom data in components and this is exactly the implementation I'd like to use

[romhml]

@adamdehaven This implementation isn’t production-ready. I ended up rewriting it in Nuxt UI for the devtools (here’s the link if you’d like to take a look). To improve stability and parsing, it would be better to leverage Vue's language-tools.

@farnabaz I think we can roll it back for now.

[adamdehaven]

@romhml I'm using the /api/component-meta endpoint (without a component name) to get all components, then looping through them to provide data to a downstream app.

I'm really just wanting to be able to add a "description" of each component (although it's likely I'll want to add more data over time) from the component itself rather than needing to do a lookup (e.g. in a static map of name => descriptions)