Improve VAT rate validation

#623

app/models/invoice.rb

@@ -28,8 +28,9 @@ class Invoice < ActiveRecord::Base
   validates :billing_email, email_format: { message: :invalid }, allow_blank: true
 
   validates :due_date, :currency, :seller_name,
-            :seller_iban, :buyer_name, :invoice_items, :vat_rate, presence: true
-  validates :vat_rate, numericality: { greater_than_or_equal_to: 0, less_than_or_equal_to: 99 }, allow_nil: true
+            :seller_iban, :buyer_name, :invoice_items, presence: true
+  validates :vat_rate, numericality: { greater_than_or_equal_to: 0, less_than: 100 },
+            allow_nil: true
 
   before_create :set_invoice_number, :check_vat
 

app/models/registrar.rb

@@ -21,7 +21,7 @@ class Registrar < ActiveRecord::Base
   validates :vat_rate, presence: true, if: :vat_rate_required?
   validates :vat_rate, absence: true, if: :local_vat_payer?
   validates :vat_rate, absence: true, if: 'foreign_vat_payer? && vat_no?'
-  validates :vat_rate, numericality: { greater_than_or_equal_to: 0, less_than_or_equal_to: 99.9 },
+  validates :vat_rate, numericality: { greater_than_or_equal_to: 0, less_than: 100 },
             allow_nil: true
 
   validate :forbid_special_code

test/models/invoice_test.rb

@@ -9,26 +9,22 @@ class InvoiceTest < ActiveSupport::TestCase
     assert @invoice.valid?
   end
 
-  def test_invalid_without_vat_rate
+  def test_valid_without_vat_rate
     @invoice.vat_rate = nil
-    assert @invoice.invalid?
-  end
-
-  def test_allows_absent_vat_rate
-    @invoice.vat_rate = nil
-    @invoice.validate
     assert @invoice.valid?
   end
 
-  def test_rejects_negative_vat_rate
+  def test_vat_rate_validation
     @invoice.vat_rate = -1
-    @invoice.validate
     assert @invoice.invalid?
-  end
 
-  def test_rejects_vat_rate_greater_than_max
+    @invoice.vat_rate = 1
+    assert @invoice.valid?
+
+    @invoice.vat_rate = 99.9
+    assert @invoice.valid?
+
     @invoice.vat_rate = 100
-    @invoice.validate
     assert @invoice.invalid?
   end
 end