ShopQuick - Rule 2

rule2.swift

    func addProduct(product: Product) {
        
        let newProduct = Product(name: product.name, qty: 0)
        
        if let _ = lastProductPurchased,
           let index : Int = self.findIndexForProductName(lastProductPurchased!.name) {
                
            // if the new product already exists
            if let _ = self.findProductByName(newProduct.name) {
                // do nothing -- Rule #2
            }
            else {
                self.insertProduct(newProduct, atIndex: index + 1)
            }
            
        }

        lastProductPurchased = product
        
        self.saveProductsToDefaults()
    
    }