Chapter 5 - CartReducer

[bttb]

Hi Adam,

in Chapter 5 inside the CartReducer you have this:

        let existing = newStore.cart.find(item => item.product.id === p.id);
        if (existing) {
            existing.quantity += q;
        } else {
            newStore.cart = [...newStore.cart, action.payload];
        }

The problem is: If the item already exists in the cart, you change the quantity of the existing item. But: This changes storeData, because existing is inside storeData AND inside newStore. So this makes the function unpure, i.e. it is not what you want as a Reducer.

[paniaguaadrian]

And what's the correct code? I'm stuck here with a big fat error. When i add some product to the cart i see: TypeError: this.props.addToCart is not a function.

Thanks in advance!

[atmmoreira]

I fix, using #26

<ProductList products={this.props.products} addToCart={this.props.addToCart} />