[WIP] V3

[Rich-Harris]

the interesting new stuff is in https://github.com/sveltejs/svelte-upgrade/tree/v3/test/v3/samples

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Some TODOs:

• update bind:/class:/etc directives to use braces for argument (bind:foo='bar' -> bind:foo={bar})
• throw an error when methods and data have conflicting names
• existing imports in components are often dropped; haven't dug into when this is triggered. try e.g.: <script>import foo from 'foo'; export default { helpers: { foo } };</script>
• code importing onprops from 'svelte' is generated, which is not exported by Svelte (could be a Svelte problem; not sure what the intention is here)
• computed properties are still rewritten as argument-less function calls, rather than reactive declarations
• top-level statements in <script> are not moved into the separate 'static' script tag; they are left in the default per-instance script

[Conduitry]

Absolutely not an important complaint, but: Could this please not clobber the EOF newline if the input file has one?

[Rich-Harris]

Good point — done

[Conduitry]

I'm experimenting with running a few components I've written through this, and I just realized two things. 1) I apparently wrote a component with a method and a data item of the same name (!), and 2) this does not handle them well.

Things could be renamed if they were only used internally, but if both are exported, this is impossible to resolve automatically, as both get squished into one namespace. Perhaps another kind of warning or error message, indicating that manual edits are required?

[Conduitry]

This also does not update class: directives to use braces around their argument, if that is something we settled on.

[Rich-Harris]

Yeah, it's not quite up to date — it's not fixing directives per the latest in the RFC. I was waiting to see if anyone strongly disagreed about that first. Same for ref:foo --> bind:this={foo}

Just realised I have some commits locally as well, will push those now

[Rich-Harris]

It might throw an error now if you have conflicting methods/data, I can't remember if I did that already

[Conduitry]

Just pulled and built and re-ran and it looks like no, it does not complain about conflicting data and methods yet.

[rob-balfre]

Any plans to continue work on this? Got a large v2 code base and wanted to avoid a large refactor

[tivac]

We're in the process of doing a gradual port to v3 using svelte-translator (shameless self plug) but I'd love to see this get finished off a bit. Would be great to automate the rest of the refactor as much as possible.

@Rich-Harris or @Conduitry given that it's been almost a year since the last commit should we assume this is dead?

[IgnusG]

I think it's safe to assume the priority of the team has shifted abandoning v2 altogether.
This is a bit concerning regarding the future of svelte (and v3) in general