export const function is declared but its value is never read

[Jojoshua]

Describe the bug

I've highlighted the important parts to explain the issue but basically trying to add type definition to an exported const function throws a ts error. This is similar to #2268 but doesn't involve bindings.
 

Reproduction

app.ts

export type CommonFunction = () => void;

App.svelte

<script lang="ts">
    import type { CommonFunction } from "$lib/app";

    export interface Props {
      name?: string;
    }

    let { name = "world" }: Props = $props();

    export const MyFunction2: CommonFunction = () =>{
      console.log("Hello from MyFunction!");
    }

  </script>

Expected behaviour

No errors are thrown for any exports

System Info

• OS: [e.g. Windows]
• IDE: [e.g. VSCode, Atom]

Which package is the issue about?

No response

Additional Information, eg. Screenshots

Note adding //@ts-ignore silences the error, everything does work but would rather not ignore all these errors

[jasonlyu123]

Seems like this specific situation is still not fixed but it should work now when there is no explict type annotation.

[Jojoshua]

Seems like this specific situation is still not fixed but it should work now when there is no explict type annotation.

You're right, we tested svelte check 4.1.6 and still getting the error. The type definition is important to have. Can you just mark anything with export as something to ignore?

[jasonlyu123]

@dummdidumm Did you remember why export const with type annotation is omitted here?

language-tools/packages/svelte2tsx/src/svelte2tsx/nodes/ExportedNames.ts

Line 767 in 0ae2758

`, exports: {${this.createReturnElements(this.usesRunes() ? others : [], false, true)}} as any as { ` +

If I understand correctly, this is the reason why only the typed export const is unused. But not really sure what the intention is here.

[dummdidumm]

uuuh I think I wanted to have it the other way around - i.e. only those that don't have a type are omitted. The reasoning was that those without a type are referenced as typeof theExportedConst in the type that follows, which means they are used. Those with a type referenced via their type, so they need to be referenced somehow else, which my PR attempted to do (but failed because I switched it up)