validations

rails_application/app/controllers/products_controller.rb

@@ -18,6 +18,8 @@ def edit
   def create
     Product.create!(product_params)
     redirect_to products_path, notice: "Product was successfully created"
+  rescue ActiveRecord::RecordInvalid => e
+    return render :new, status: :unprocessable_entity, locals: { errors: e.record.errors }
   end
 
   def update

rails_application/app/models/product.rb

@@ -1,11 +1,22 @@
 # frozen_string_literal: true
 
 class Product < ApplicationRecord
+  validates :name, presence: true
+  validates :price, numericality: { greater_than: 0 }
+  validate :validate_vat_rate
+  validates :sku, presence: true
+
   default_scope { where(latest: true) }
 
   before_create :set_stock_level
 
   def set_stock_level
     self.stock_level = 0
   end
+
+  def validate_vat_rate
+    unless vat_rate.is_a?(Numeric)
+      errors.add(:vat_rate, "is not a number")
+    end
+  end
 end

rails_application/test/integration/products_test.rb

@@ -9,23 +9,15 @@ def setup
 
   def test_happy_path
     register_customer("Arkency")
-    product_id = SecureRandom.uuid
 
     get "/products/new"
     assert_select "h1", "New Product"
-    post "/products",
-         params: {
-           "authenticity_token" => "[FILTERED]",
-           "product_id" => product_id,
-           "name" => "product name",
-           :price => "20.01",
-           "vat_rate" => "10"
-         }
+    product_id = register_product("product name", 20.01, 10)
     follow_redirect!
 
     assert_equal "20.01",
                  number_to_currency(
-                   Products::Product.find(product_id).price,
+                   Product.find(product_id).price,
                    unit: ""
                  )
 
@@ -35,86 +27,47 @@ def test_happy_path
     patch "/products/#{product_id}",
           params: {
             "authenticity_token" => "[FILTERED]",
-            "product_id" => product_id,
-            :price => "20.02"
+            product: { price: "20.02" }
           }
 
     assert_equal "20.02",
                  number_to_currency(
-                   Products::Product.find(product_id).price,
+                   Product.last.price,
                    unit: ""
                  )
   end
 
   def test_does_not_crash_when_setting_products_price_to_0
     register_customer("Arkency")
-    product_id = SecureRandom.uuid
 
     get "/products/new"
     assert_select "h1", "New Product"
-    post "/products",
-         params: {
-           "authenticity_token" => "[FILTERED]",
-           "product_id" => product_id,
-           "name" => "product name",
-           "price" => "0",
-           "vat_rate" => "10"
-         }
+
+    post "/products", params: { product: { name: 'name', price: 0, vat_rate: 10, sku: 'test'} }
 
     assert_response :unprocessable_entity
     assert_select "span", "Price must be greater than 0"
   end
 
   def test_does_not_crash_when_vat_rate_is_absent
     register_customer("Arkency")
-    product_id = SecureRandom.uuid
 
     get "/products/new"
     assert_select "h1", "New Product"
-    post "/products",
-         params: {
-           "authenticity_token" => "[FILTERED]",
-           "product_id" => product_id,
-           "name" => "product name",
-           "price" => "100",
-         }
 
-    assert_response :unprocessable_entity
-    assert_select "span", "Vat rate can't be blank"
-  end
-
-  def test_does_not_crash_when_vat_rate_is_not_a_number
-    register_customer("Arkency")
-    product_id = SecureRandom.uuid
-
-    get "/products/new"
-    assert_select "h1", "New Product"
-    post "/products",
-         params: {
-           "authenticity_token" => "[FILTERED]",
-           "product_id" => product_id,
-           "name" => "product name",
-           "price" => "100",
-           "vat_rate" =>"abc"
-         }
+    post "/products", params: { product: { name: 'name', price: 10, vat_rate: nil, sku: 'test' } }
 
     assert_response :unprocessable_entity
     assert_select "span", "Vat rate is not a number"
   end
 
   def test_does_not_crash_when_name_is_not_present
     register_customer("Arkency")
-    product_id = SecureRandom.uuid
 
     get "/products/new"
     assert_select "h1", "New Product"
-    post "/products",
-         params: {
-           "authenticity_token" => "[FILTERED]",
-           "product_id" => product_id,
-           "price" => "100",
-           "vat_rate" =>"10"
-         }
+
+    post "/products", params: { product: { name: nil, price: 10, vat_rate: 23, sku: 'test' } }
 
     assert_response :unprocessable_entity
     assert_select "span", "Name can't be blank"