Support rename in Svelte files

[dummdidumm]

Is your feature request related to a problem? Please describe.
Currently, I cannot do rename refactorings in svelte files.

Describe the solution you'd like
Allow rename refactorings inside svelte files to work so that

• I can change prop names and all dependent files get updated
• I can change variables/functions inside svelte files
• I can change variables/functions outside in js/ts files and if they are used inside svelte files, those are updated aswell

Additional context
I started prototyping this. Renames of variables/functions inside svelte files can be implemented quickly.

However implementing prop renames requires changes to svelte2tsx. It seems that right now there is no mapping from export let X to the generated jsx-prop.

Another problem is that when you do a rename inside ts/js, the language server does not pick that up because he is only registered to react to changes of svelte files. To fix that, it would need to register for js/ts files, too, which requires some work to differ between svelte and ts/js documents and not for example run diagnostics of the HTMLPlugin on js/ts files. Maybe this could come as a second step, after renaming inside svelte files works.

[dummdidumm]

Rename so far now works for:

• Variables inside a svelte file's script tag
• Component props, but they can only be renamed inside the component which exports the prop

It does not yet work for:

• Component props if you want to rename the prop but are in another file which uses that component
• Generally attributes/bindings inside the template cannot be renamed when you want to trigger the rename in said template. Works inside script tag though.

[imekachi]

There is another scenario, where a svelte file imports a variable from another file (.js, .ts)
and you rename that variable in other file, it doesn't update variable imported in .svelte

I think it has something to do with referencing variables, because it cannot find reference from .svelte file as well

[dummdidumm]

To support this we need to write a TypeScript plugin, which is tracked in #580

[dummdidumm]

There exists a TypeScript plugin now which comes packaged with the VS Code extension and which you need to enable through the settings. It also is available standalone as a npm package if you need to use it outside of VS Code.
The plugin fixes the issue of renaming stuff inside TS/JS files and updating Svelte files, too.

[imekachi]

I can confirm that everything works now in VS Code with the plugin and svelte.enable-ts-plugin: true

• renaming from other file types
• finding references from other file types

Thank you @dummdidumm