No type hints when using dispatch about redux-thunk

[laat]

Is the problem that type cannot be inferred here?

declare function unionArg(
  x: { type: 'FOO' } | { type: 'BAR'; x: number } | (() => void)
): void;

// type is any when hovering in vscode?
unionArg({type: })

I do not think this is an issue with redux-thunk. It is a usability issue with typescript, because the types are correct.

[zqran]

@laat The key point is not that the type of type property is any, but when you typing the type attribute, there is no type hint.

declare function unionArg(
  x: { type: 'FOO' } | { type: 'BAR'; x: number } | (() => void)
): void;

// type is any when hovering in vscode?
unionArg({type: })

However, the code you provided will prompt you when you typing the type attribute.

[laat]

I see, yes I can reproduce it. It's strange that it is aware of the types, but unable to complete.

[markerikson]

I spent some time today playing around with this. Loosely put, if I try rearranging the overloads, I can get correct inference for type here, but some of our other typetests fail.

This is an edge case anyway. We generally expect that A) the thunk middleware will not be typed to be restricted to a specific set of dispatchable actions (per https://redux.js.org/usage/usage-with-typescript#avoid-action-type-unions ), and B) users won't normally be hand-writing a type field in a plain action object as they dispatch because they'll be using action creators.

Given that, I don't think this is something we're going to fix, unless someone else comes up with a way to rearrange the types without breaking things.