Añade validador de existencias a ProductCart

3 files changed, 18 insertions, 1 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
diff --git a/spec/factories/product_cart.rb b/spec/factories/product_cart.rb
index 713fd0a..95094dd 100644
--- a/spec/factories/product_cart.rb
+++ b/spec/factories/product_cart.rb
@@ -3,7 +3,7 @@
 FactoryBot.define do
   factory :product_cart, class: 'ProductCart' do
     cart { create(:cart) }
-    product { create(:product) }
+    product { create(:product, available_quantity: 2000) }
     quantity { rand(1..1000) }
   end
 end
diff --git a/spec/models/product_cart_spec.rb b/spec/models/product_cart_spec.rb
index 2c4d9d1..46860d3 100644
--- a/spec/models/product_cart_spec.rb
+++ b/spec/models/product_cart_spec.rb
@@ -20,4 +20,14 @@ RSpec.describe ProductCart, type: :model do
       expect(another_product_cart.errors[:product_id]).to be_present
     end
   end
+
+  describe '#product_quantity' do
+    it "validates the requested quantity against the product's available quantity" do
+      product = create(:product, available_quantity: 5)
+      another_product_cart = build(:product_cart, cart: product_cart.cart, product:, quantity: 10)
+
+      expect(another_product_cart.save).to be_falsey
+      expect(another_product_cart.errors[:product_id][0]).to eq('not enough in existence')
+    end
+  end
 end