Typescript, Object is of type 'unknown'

Question

I have this code:

const dataId = await getData(id);

const result = dataId.requestPayload.officePaymentId; // error here

I get Object is of type 'unknown'

The function getData() is this one:

import { Agent } from '../types';
export default async function getData<T>(
  id: string
): Promise<Agent<T>> {
  const Item = [something];

  return Item as Agent<T>;
}

the Agent interface is:

export interface Agent<T> {
  id: string;
  requestPayload: T;
}

How can I pass the definiton of the generic when I call the function getData ? Or why I'm getting the mentioned error. Any hint please

Answer 1

You should pass the type to getData

const dataId = await getData<MyPayload>(id);

where MyPayload is the type with the property officePaymentId

Playground link

Answer 2

Typescript is waiting you to specify the type T when calling getData .

To do so use the <TYPE>func(arguments) syntax, example:

const dataId = await getData<{
  officePaymentId: string;
}>('foo');

Playground example