Redux Toolkit TS Example API

RTK-example-API.ts

import { Reducer } from "redux";
import {
  createAction,
  createReducer,
  PayloadAction,
  PayloadActionCreator,
} from "@reduxjs/toolkit";

const fetchUserBlogPosts = createAction<{
  userId: number;
  categoryId?: number;
  fullText?: boolean;
}>("fetch-user-blog-posts");

type TravReducer = Reducer & {
  addCase<P, T extends string, M, E>(
    actionType: PayloadActionCreator<P, T>,
    handler: (state: null, action: PayloadAction<P, T>) => void,
  ): void;
};

const myReducer: TravReducer = createReducer({ posts: [] }, {}) as any;

myReducer.addCase(fetchUserBlogPosts, (state, action) => {
  // type of `action` is inferred correctly here
  console.log(action.payload.userId);
});