[FIX] authorize: add error-checking

Previous to this commit, if a user hadn't properly set up his
Authorize.net credentials, when getting a response from Authorize.net's
servers, we would expect some attributes to be in the response's body,
but this is not the case if the credentials are wrong, thus we would
have an unexpected error like "NoneType object has no attribute text"
which is only a sympton of the real error (bad credentials and no
error-checking).

This is fixed by checking if the response body contains an error
message, if it is the case we raise an UserError with the error code and
the error message (which is only shown if debug mode is activated).

OPW 788261

addons/payment_authorize/models/authorize_request.py

@@ -150,6 +150,22 @@ class AuthorizeAPI():
         etree.SubElement(creditCard, "cardCode").text = card_code
         etree.SubElement(root, "validationMode").text = 'liveMode'
         response = self._authorize_request(root)
+
+        # If the user didn't set up authorize.net properly then the response
+        # won't contain stuff like customerProfileId and accessing text
+        # will raise a NoneType has no text attribute
+        msg = response.find('messages')
+        if msg is not None:
+            rc = msg.find('resultCode')
+            if rc is not None and rc.text == 'Error':
+                err = msg.find('message')
+                err_code = err.find('code').text
+                err_msg = err.find('text').text
+                raise UserError(
+                    "Authorize.net Error:\nCode: %s\nMessage: %s"
+                    % (err_code, err_msg)
+                )
+
         res = dict()
         res['profile_id'] = response.find('customerProfileId').text
         res['payment_profile_id'] = response.find('customerPaymentProfileIdList/numericString').text