Comment TypeScript type-t-il dispatch de useReducer ?

type Action =
  | { type: "increment" }
  | { type: "decrement" }
  | { type: "set"; payload: number };

function reducer(state: number, action: Action): number {
  switch (action.type) {
    case "increment": return state + 1;
    case "decrement": return state - 1;
    case "set": return action.payload;
  }
}

const [count, dispatch] = useReducer(reducer, 0);