Variable used in 'key' appears as unused

[Kruptein]

The below template gives a "'i' is declared but its value is never read." in both volar and vue-tsc.

<template v-for="[i, part] of someObject" :key="i">
  {{ part }}
</template>

While the i is indeed not used inside the template itself, it is used in the key and can thus not simply be removed.

A temporary workaround can be:

<template v-for="something of someObject" :key="something[0]">
  {{ something[1] }}
</template>

[johnsoncodehk]

Vue template AST doesn't provide key binding from ForNode so we can't fix it yet.

[bartenra]

Sorry for posting a duplicate!

How can I tell Volar to ignore an issue in a template?

[johnsoncodehk]

@bartenra you can use _index instead of index as variable name.

[Zehir]

Vue template AST doesn't provide key binding from ForNode so we can't fix it yet.

Is there any changes about this issue in the last year ? Thanks

[johnsoncodehk]

@Zehir unfortunately we have nothing can do here, you can open an issue in vue/core repo.

[Kruptein]

This actually nowadays works properly in my setup. Unsure if I should close the issue or not given that apparently Zehir still has issues.

[Zehir]

By using a _ prefix to your variables names ?

[Kruptein]

No, with the proper names.

I just tested the following quickly:

<div v-for="[i, layer] of layers" :key="i">
    {{ layer }}
</div>

and this does not complain. If I remove the key section it properly complains that i is not used.

[Zehir]

I have 2 project, in one of them I don't have the issue.
What is the type definition of layers ?