Merge pull request #491 from 3scale/fix/negative-invoices

[billing] Cancel non-positive invoices on charge

app/models/invoice.rb

@@ -429,6 +429,7 @@ def charge!(automatic = true)
 
     unless chargeable?
       logger.info "Not charging invoice ID #{self.id} (#{reason_cannot_charge})"
+      cancel! unless positive?
       return
     end
 
@@ -501,10 +502,8 @@ def not_paid?
   CONDITIONS_TO_CHARGE = %i[not_paid provider_present provider_payment_gateway_configured positive buyer_account_paying_monthly].freeze
 
   def reason_cannot_charge
-    CONDITIONS_TO_CHARGE.each do |condition_method|
-      return I18n.t(condition_method, scope: %i[invoices reasons_cannot_charge]) unless method("#{condition_method}?").call
-    end
-    nil
+    reason = CONDITIONS_TO_CHARGE.find { |condition| !method("#{condition}?").call }
+    I18n.t(reason, scope: %i[invoices reasons_cannot_charge]) if reason
   end
 
   def chargeable?

test/unit/invoice_test.rb

@@ -314,6 +314,13 @@ def build_invoice(attributes = {})
     assert build_invoice.chargeable?
   end
 
+  test 'charge! should cancel the invoice if negative' do
+    @invoice.update_attribute(:state, 'pending')
+    @invoice.stubs(:cost).returns(-100.0.to_has_money('EUR'))
+    refute @invoice.charge!
+    assert_equal 'cancelled', @invoice.state
+  end
+
   test 'charge! should raise if cancelled or paid' do
     @invoice.cancel!
     assert_raises(Invoice::InvalidInvoiceStateException) { @invoice.charge! }