.svelte files not accepting script='ts' when being created occasionally?

[orta]

Error: "unexpected token" in TypeScript

Describe the bug

To Reproduce
Steps to reproduce the behavior:

I ran npx degit dummdidumm/template svelte-typescript-app then added a new file

It was fixable by reloading the editor

Expected behavior
New file being TS'd in the IDE

Screenshots
Above

System (please complete the following information):

• OS: Mac
• IDE: VS Code
• Plugin/Package: Prod

[jasonlyu123]

language-tools/packages/language-server/src/plugins/svelte/SveltePlugin.ts

Line 138 in ba274d5

svelteDoc?.config && !svelteDoc.config.loadConfigError

This is because of the caching of preprocessing config

[dummdidumm]

Why does the config cache interfere with the language detection? The language detection is done through the attributes.

[jasonlyu123]

If my understanding is correct, when you have a script tag without lang first

<script><script>

The config would be cached as don't need any fallback preprocessor.

[orta]

That fits in my head

[dummdidumm]

Oh right, I get the situation now: This can only happen if the user does not have a svelte.config.js, then adds the lang="ts". This would fit your reproduction because my template does not have a svelte.config.js.

• Solution 1: return the fallback preprocessor either way. Then this would work with lang="ts". For more, the user has to add a svelte.config.js and then requiring the user to restart for the config to take effect is reasonable.
• Solution 2: if no config was found, try to find one each time, so don't cache anything until something is found.

Preferences?

[dummdidumm]

I dediced to go with solution 1.