1 files changed, 7 insertions, 0 deletions
diff --git a/app/models/product_cart.rb b/app/models/product_cart.rb
index 09e7a25..d4232cb 100644
--- a/app/models/product_cart.rb
+++ b/app/models/product_cart.rb
@@ -8,10 +8,17 @@ class ProductCart < ApplicationRecord
 
   validates :quantity, presence: true, comparison: { greater_than: 0 }
   validate :sole_product_in_cart
+  validate :product_quantity
 
   def sole_product_in_cart
     return if cart.nil? || cart.products.find_by(id: product_id).nil?
 
     errors.add(:product_id, "cart already has product with id #{product_id}")
   end
+
+  def product_quantity
+    return if product.nil? || product.available_quantity > quantity
+
+    errors.add(:product_id, 'not enough in existence')
+  end
 end