How to add field to Record in immutable.js?

Question

JavaScript

There is a product catalog in the firebase database.
The site has a shopping cart.
When you click add to cart, the product id is passed to the action and it is requested from the database and added to the state.

The state cart itself is represented as an OrderedMap.
How now in the reducer to change the requested product and add the count field (number of products) there before adding it to the state?
This is necessary in order to be able to change the number of items in the cart.
Now the product is simply added to the state as is:

case ADD_PRODUCT_TO_CART_SUCCESS: {
  return state.setIn(["entities", payload.productUid], payload.product);
}

Answer 1

case ADD_PRODUCT_TO_CART_SUCCESS: {
  return state.setIn(["entities", payload.productUid], {...payload.product, count:  ВАШЕ_КОЛИЧЕСТВО});
}

In this code, we take everything that was in payload.product and add 1 field to a new object (curly braces = new object), and also add the count field. The number (count) you will also, for sure, pass in the action. You get: count: payload.count (or whatever you call the field in your action...)
Example:

{ type: ADD_PRODUCT_TO_CART_SUCCESS,
    payload: { productUid, product, count: ваше_количество } // сюда count можно передавать из функции с помощью которой ваш экшен был создан...
  }