Incorrect return type for flush() function

[h]

Describe the bug
The type declaration of the onDebouncedCallback flush() function claims that the return type is void. However, that's incorrect: the actual return type is the same as the callback. (Or undefined if the callback has never been called yet.) This causes Typescript errors when using flush().

To Reproduce

const foo = useDebouncedCallback(() => 'abc', 500);
foo();
const result: string | undefined = foo.flush();

results in:

foobar.tsx:31:11 - error TS2322: Type 'void' is not assignable to type 'string | undefined'.

31     const result: string | undefined = foo.flush();

Expected behavior
Typescript type declaration should match the function's actual type.

use-debounce version: 10.0.0

[h]

Submitted a fix for review in PR 173

[xnimorz]

Thanks @h !

[xnimorz]

Merged, I'll cut a new version shortly

[xnimorz]

Published use-debounce@10.0.1