Wrong no-unsafe-member-access for reactive assignments and store subscriptions

[dummdidumm]

#87 uncovered some limitations when using type-aware rules. Some of these are fixed by #88 , but not all of them. Reactive assignments and store subscriptions will fail:

<script lang="ts">
  import { writable } from 'svelte/store';
  const store = writable([]);
  $store.length; // wrong no-unsafe-member-access error
  $: assignment = [];
  assignment.length; // wrong no-unsafe-member-access error
  // You can work around this by doing
  let another_assignment: string[];
  $: another_assignment = [];
  another_assignment.length; // OK
</script>

This is because the transformation just prepends generated let X statements above the code, with no specific type set to it. For it to work correctly, we would need to do transformations inline:

• $: assignment = .. --> let assignment = .. (but only if user did not declare the let himself)
• const store = writable(...) --> const store = writable(..);let $store = get_store_value(store) (where get_store_value is a fake function returning the Value in Store<Value>)

This would be similar to how we transform code in svelte2tsx for the intellisense features. The hard part is getting the line mappings correctly afterwards.

[mohe2015]

Sorry to bump this but this is pretty annoying as stores are quite a core feature of svelte. Is there any workaround except for adding ignore directives?

[dummdidumm]

This should be fixed for stores, for reactive statements it's not working yet.

[DetachHead]

is this the same issue?

<script lang="ts">
    $: foo = 1
    foo.toString // no error
    const bar = () => {
        foo.toString // @typescript-eslint/no-unsafe-member-access
    }
</script>

[locmark]

is this the same issue?

<script lang="ts">
    $: foo = 1
    foo.toString // no error
    const bar = () => {
        foo.toString // @typescript-eslint/no-unsafe-member-access
    }
</script>

any updates on that? It's super annoying..

[wtachau]

any update?

[mohe2015]

The README of this project says it got replaced. Idk if that helps though

[wtachau]

Just noticed that :-/. I updated to eslint-plugin-svelte, which seems like it mostly works, though now I have to change some other configs. (For any future curious readers, I'm looking at https://github.com/sveltejs/eslint-plugin-svelte#parser-configuration and sveltejs/language-tools#650)