useState type differences between React and Preact

[luhis]

• Check if updating to the latest Preact version resolves the issue

Describe the bug
The type definitions for useState differ slightly.

React: https://github.com/DefinitelyTyped/DefinitelyTyped/blob/master/types/react/index.d.ts#L913
Preact: https://github.com/preactjs/preact/blob/master/hooks/src/index.d.ts#L10

The React definitions allow for calling useState with no initialState, and it will infer a state of type T | undefined. In Preact I must pass in an undefined as the initialState, and create a union with undefined for the type.

Preact valid code:

const [editingObject, setEditingObject] = useState<{id: number} | undefined>(
        undefined
    );

To Reproduce

const [editingObject, setEditingObject] = useState<{ id: number }>();

Expected behavior
This should compile and infer a state of type { id: number } | undefined