Stripe: Parse EMV ARC from error response

Closes #1750.

CHANGELOG

@@ -14,12 +14,7 @@
 * Sage: Credit really is credit not refund [duff]
 * Sage: Add ability to refund [duff]
 * Cardstream: Add scrubbing [anellis]
-* Litle: Add debt_repayment_flag [duff]
-* Litle: Add debt_repayment_flag [duff]
-* iATS: Support ACH [rwdaigle]
-* CheckoutV2: Add Gateway [anellis]
-* CenPOS: Fix refund amount issue [duff]
-* Add error_code mapping and error_code_from to gateway generator [jnormore]
+* Stripe: Parse EMV ARC from error response [bizla]
 
 
 == Version 1.50.0 (June 1, 2015)

lib/active_merchant/billing/gateways/stripe.rb

@@ -418,7 +418,7 @@ def commit(method, url, parameters = nil, options = {})
 
         success = !response.key?("error")
 
-        card = response["card"] || response["active_card"] || response["source"] || {}
+        card = card_from_response(response)
         avs_code = AVS_CODE_TRANSLATOR["line1: #{card["address_line1_check"]}, zip: #{card["address_zip_check"]}"]
         cvc_code = CVC_CODE_TRANSLATOR[card["cvc_check"]]
 
@@ -429,7 +429,7 @@ def commit(method, url, parameters = nil, options = {})
           :authorization => success ? response["id"] : response["error"]["charge"],
           :avs_result => { :code => avs_code },
           :cvv_result => cvc_code,
-          :emv_authorization => card["emv_auth_data"],
+          :emv_authorization => emv_authorization_from_response(response),
           :error_code => success ? nil : STANDARD_ERROR_CODE_MAPPING[response["error"]["code"]]
         )
       end
@@ -459,6 +459,16 @@ def non_fractional_currency?(currency)
       def emv_payment?(payment)
         payment.respond_to?(:emv?) && payment.emv?
       end
+
+      def card_from_response(response)
+        response["card"] || response["active_card"] || response["source"] || {}
+      end
+
+      def emv_authorization_from_response(response)
+        return response["error"]["emv_auth_data"] if response["error"]
+
+        card_from_response(response)["emv_auth_data"]
+      end
     end
   end
 end

test/unit/gateways/stripe_test.rb

@@ -214,6 +214,17 @@ def test_successful_authorization_with_emv_credit_card
     assert response.emv_authorization, "Response should include emv_authorization containing the EMV ARPC"
   end
 
+  def test_declined_authorization_with_emv_credit_card
+    @gateway.expects(:ssl_request).returns(declined_authorization_response_with_emv_auth_data)
+
+    assert response = @gateway.authorize(@amount, @emv_credit_card, @options)
+    assert_instance_of Response, response
+    assert_failure response
+
+    assert_equal 'ch_declined_auth', response.authorization
+    assert response.emv_authorization, "Response should include emv_auth_data containing the EMV ARC"
+  end
+
   def test_successful_capture
     @gateway.expects(:ssl_request).returns(successful_capture_response)
 
@@ -1305,6 +1316,21 @@ def declined_authorization_response
     RESPONSE
   end
 
+  def declined_authorization_response_with_emv_auth_data
+    <<-RESPONSE
+    {
+     "error": {
+       "message": "Your card was declined.",
+       "type": "card_error",
+       "code": "card_declined",
+       "decline_code": "generic_decline",
+       "charge": "ch_declined_auth",
+       "emv_auth_data": "8A023531910ACD16B371D277FDB90000"
+     }
+    }
+    RESPONSE
+  end
+
   def successful_update_credit_card_response
     <<-RESPONSE
     {