export type Handlers<T> = {
  [type: string]: (state: T, action: any) => T;
};

export function createReducer<S>(handlers: Handlers<S>, initialState: S) {
  return (state: S = initialState, action: AnyAction) => {
    const handler = handlers[action.type];
    if (handler) return handler(state, action);
    return state;
  };
}