Diagnostic message "Stores must be declared at the top level of the component" gives invalid line number

Describe the bug The diagnostic message Stores must be declared at the top level of the component comes with a line number of -1, which is invalid: https://microsoft.github.io/language-server-protocol/specification#position This breaks diagnostics in my editor.

To Reproduce Here is a minimal file that repros this for me:

<script lang="ts">
    import { writable } from "svelte/store";

    let foo = writable("value");
    function bar() {
        let bar = foo;
        console.log($bar);
    }
</script>

Expected behavior The line number should ideally be the line number of the underlying problem, but at the very least (if this is an upstream svelte problem) it should be validated to be non-negative, eg setting it to 0.

Screenshots If applicable, add screenshots to help explain your problem.

System (please complete the following information):

• OS: Mac OS 12.0
• IDE: Neovim
• Plugin/Package: svelte-language-server 0.14.13

[jasonlyu123]

Does a version bump help us

It’s fixed in https://github.com/sveltejs/svelte-preprocess/pull/407

though I still consider this a bug–if the language server runs into problems like this it should fail more gracefully than sending invalid diagnostic

Yeah we also should fix the line number.

[dummdidumm]

Did you have a tsconfig.json or jsconfig.json? From my debugging, it seems like the version of the svelte-preprocess we’re bundling doesn’t quite work when there isn’t either of them. The forced sourcemap option we passed also doesn’t work. We might have to consider bumping the version.

Does a version bump help us, or is this something that’s still a problem inside svelte-preprocess? Or is it just a configuration problem on our end? Maybe we need to pass sourceMap: true as well?

        return {
            preprocess: sveltePreprocess({
                sourceMap: true, //<<-- add this line
                // 4.x does not have transpileOnly anymore, but if the user has version 3.x
                // in his repo, that one is loaded instead, for which we still need this.
                typescript: <any>{
                    transpileOnly: true,
                    compilerOptions: { sourceMap: true, inlineSourceMap: false }
                }
            })
        };