Utilizing addMatcher with ExtraReducers for Complex Matching Logic

import { createAction, createSlice } from '@reduxjs/toolkit';

// Define some action creators outside of the slice
const actionOne = createAction('action/one');
const actionTwo = createAction('action/two');

// Example of complex matching logic using a type predicate
const isActionWithId = (action) => action.payload && typeof action.payload.id === 'number';

// Create slice with extraReducers using addMatcher for complex logic
const mySlice = createSlice({
  name: 'mySlice',
  initialState: {},
  reducers: {},
  extraReducers: (builder) => {
    // Add a matcher to handle multiple actions with similar characteristics
    builder.addMatcher(
      isActionWithId,
      (state, action) => {
        // Assume state.entities is a map/dictionary
        const { id } = action.payload;
        if (!state.entities[id]) {
          // Initialize entity if it doesn't exist
          state.entities[id] = { data: null, loadingState: 'idle' };
        }
        // Handle action here, e.g., set loading state
        state.entities[id].loadingState = 'loading';
      }
    );
    // Handle other actions as needed using standard methods
    builder.addCase(actionOne, (state, action) => { /* handle action */ });
    builder.addCase(actionTwo, (state, action) => { /* handle action */ });
  }
});