createReducerLogic.ts

import { makeReducer, makeActionCreators } from './makeReducer';

const createReducer = <
  State,
  Actions extends { [K in keyof Actions]: (payload?: any) => void }
>({
  initialState,
  actions,
}: Params<State, Actions>): CreateReducerReturnedObject<State, Actions> => {
  const reducer = makeReducer({
    initialState,
    actions,
  });

  const actionCreators = makeActionCreators({ actions });

  return {
    // @ts-ignore
    constants: Object.keys(actions).reduce(
      (object, key) => ({ ...object, [key]: key }),
      {}
    ),
    reducer,
    // @ts-ignore
    actions: actionCreators,
  };
};

interface Params<
  State,
  Actions extends { [K in keyof Actions]: (payload?: any) => void }
> {
  initialState: State;
  actions: ActionDefinition<State, Actions>;
}

interface CreateReducerReturnedObject<
  State,
  Actions extends { [K in keyof Actions]: (payload?: any) => void }
> {
  constants: {
    [K in keyof Actions]: K;
  };
  reducer: (
    state: State,
    action: {
      type: keyof Actions;
      payload?: Parameters<Actions[keyof Actions]>[0];
    }
  ) => State;
  actions: {
    [K in keyof Actions]: (...args: Parameters<Actions[K]>) => {
      type: string;
      payload?: Parameters<Actions[K]>[0]
    }
  };
}

type ActionDefinition<
  State,
  Actions extends { [K in keyof Actions]: (payload?: any) => void }
> = {
  [K in keyof Actions]: (
    state: State,
    payload: Parameters<Actions[K]>[0]
  ) => State;
};

const { constants, reducer, actions } = createReducer<State, Actions>({
  initialState: {
    isOpen: false,
  },
  actions: {
    changeModalState: (state, isOpen) => ({
      ...state,
      isOpen,
    }),
  },
});

const createdAction = actions.changeModalState(true)

interface State {
  isOpen: boolean;
}

interface Actions {
  changeModalState: (newState: boolean) => void;
}