Version

3.0.4

Reproduction link

https://codesandbox.io/s/thirsty-elgamal-5u8qe?file=/src/App.vue

Steps to reproduce

Use custom directive to change el.classList on binding.arg change (as dynamic directive argument). Error: "Argument of type 'string | undefined' is not assignable to parameter of type 'boolean | undefined'."

What is expected?

Use boolean value as dynamic directive argument

What is actually happening?

Type error

The argument is what goes after the :, v-mydirective:foo foo is the argument. The typings are correct.

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@posva I'm very sorry for the uncompleted reproduction (saving error, fixed now). But I need to ensure. The case looks like a good candidate for the enhancement.

According with DirectiveBinding arg can't be boolean (packages/runtime-core/src/directives.ts).

export interface DirectiveBinding<V = any> {
  instance: ComponentPublicInstance | null
  value: V
  oldValue: V | null
  arg?: string
  modifiers: DirectiveModifiers
  dir: ObjectDirective<any, V>
}

Is it correct and expecting behavior? I think (see the reproduction) boolean as arg can be useful and works without using the DirectiveBinding interface.

The existing type is correct

Ok, thanks for the confirmation