reducer.ts

type ReducerState = {
  count: number;
};

type ReducerAction =
  | {
      type: "add";
      add: number;
    }
  | {
      type: "subtract";
      subtract: number;
    };

const reducer = (state: ReducerState, action: ReducerAction) => {


const reducer: Reducer<ReducerState, ReducerAction> = (state, action) => {
  switch (action.type) {