Svelte/Vite: Prevent crash when no svelte.config file

[JustinEloffBBD]

What I did

The svelteDocgen plugin crashes Storybook if you have no svelte config file defined. It tries to destructure the options, but with no config file, this value is null, causing a crash. Setting an empty object as a fallback looks like it solved the issue.

How to test

Have no svelte.config.js file. Run storybook.

Checklist

I havn't done any integration/unit testing here. Just made a quick edit on github to propose a potential fix. If this is an issue for this change I can take a more thorough approach tomorrow.

• Make sure your changes are tested (stories and/or unit, integration, or end-to-end tests)
• Make sure to add/update documentation regarding your changes
• If you are deprecating/removing a feature, make sure to update
  MIGRATION.MD

Maintainers

• If this PR should be tested against many or all sandboxes,
  make sure to add the ci:merged or ci:daily GH label to it.
• Make sure this PR contains one of the labels below.

["cleanup", "BREAKING CHANGE", "feature request", "bug", "documentation", "maintenance", "dependencies", "other"]

[IanVS]

Thanks for catching this, @JustinEloffBBD, and for the PR.

I think this change would work, but let's solve it closer to the cause, in the plugin, by adding a default to the parameter:

// code/frameworks/svelte-vite/src/plugins/svelte-docgen.ts

export function svelteDocgen(svelteOptions: Record<string, any> = {}): PluginOption {

That way we won't run into this in the future if we need to use the plugin elsewhere.

[JustinEloffBBD]

Cool. I have updated the code accordingly, also tested it on a stock svelte project, with no config file, still works.

[IanVS]

LGTM, thanks!