add amount exceed business exception and unit test

pay-api/src/pay_api/models/eft_credit.py

@@ -61,8 +61,3 @@ class EFTCredit(BaseModel):  # pylint:disable=too-many-instance-attributes
     def find_by_payment_account_id(cls, payment_account_id: int):
         """Find EFT Credit by payment account id."""
         return cls.query.filter_by(payment_account_id=payment_account_id).all()
-
-    @classmethod
-    def find_by_short_name_id(cls, short_name_id: int):
-        """Find EFT Credit by short name id."""
-        return cls.query.filter_by(short_name_id=short_name_id).all()

pay-api/src/pay_api/services/eft_service.py

@@ -20,6 +20,7 @@
 from flask import current_app
 from jinja2 import Environment, FileSystemLoader
 
+from pay_api.exceptions import BusinessException
 from pay_api.models import CfsAccount as CfsAccountModel
 from pay_api.models import EFTCredit as EFTCreditModel
 from pay_api.models import EFTRefund as EFTRefundModel
@@ -29,9 +30,11 @@
 from pay_api.models import PaymentAccount as PaymentAccountModel
 from pay_api.models import Receipt as ReceiptModel
 from pay_api.models.eft_refund_email_list import EFTRefundEmailList
+from pay_api.services.eft_short_names import EFTShortnames
 from pay_api.services.email_service import send_email
 from pay_api.utils.enums import (
     CfsAccountStatus, EFTCreditInvoiceStatus, InvoiceReferenceStatus, PaymentMethod, PaymentStatus, PaymentSystem)
+from pay_api.utils.errors import Error
 from pay_api.utils.user_context import user_context
 from pay_api.utils.util import get_str_by_path
 
@@ -123,7 +126,7 @@ def create_shortname_refund(cls, request: Dict[str, str], **kwargs) -> Dict[str,
         current_app.logger.debug(f'Starting shortname refund : {shortname_id}')
 
         refund = cls._create_refund_model(request, shortname_id, amount, comment)
-        cls._refund_eft_credits(shortname_id, amount)
+        cls._refund_eft_credits(int(shortname_id), amount)
 
         recipients = EFTRefundEmailList.find_all_emails()
         subject = f'Pending Refund Request for Short Name {shortname}'
@@ -133,10 +136,15 @@ def create_shortname_refund(cls, request: Dict[str, str], **kwargs) -> Dict[str,
         refund.save()
 
     @classmethod
-    def _refund_eft_credits(cls, shortname_id: str, amount: str):
+    def _refund_eft_credits(cls, shortname_id: int, amount: str):
         """Refund the amount to eft_credits table based on short_name_id."""
         refund_amount = Decimal(amount)
-        eft_credits = EFTCreditModel.find_by_short_name_id(int(shortname_id))
+        eft_credits: List[EFTCreditModel] = EFTShortnames.get_eft_credits(shortname_id)
+        eft_credit_balance = EFTShortnames.get_eft_credit_balance(shortname_id)
+
+        if refund_amount > eft_credit_balance:
+            current_app.logger.error(f'Shortname {shortname_id} Refund amount exceed eft_credits remaining amount.')
+            raise BusinessException(Error.INVALID_TRANSACTION)
 
         for credit in eft_credits:
             if refund_amount <= 0:
@@ -145,18 +153,12 @@ def _refund_eft_credits(cls, shortname_id: str, amount: str):
             if credit_amount <= 0:
                 continue
 
-            if refund_amount <= credit_amount:
-                credit.remaining_amount -= refund_amount
-                refund_amount = Decimal(0)
-            else:
-                refund_amount -= credit_amount
-                credit.remaining_amount = Decimal(0)
+            deduction = min(refund_amount, credit_amount)
+            credit.remaining_amount -= deduction
+            refund_amount -= deduction
 
             credit.save()
 
-        if refund_amount > 0:
-            current_app.logger.error(f'Shortname {shortname_id} Refund amount exceed eft_credits remaining amount.')
-
     @classmethod
     def _create_refund_model(cls, request: Dict[str, str],
                              shortname_id: str, amount: str, comment: str) -> EFTRefundModel:

pay-api/tests/unit/services/test_eft_service.py

@@ -19,10 +19,10 @@
 
 from unittest.mock import MagicMock, patch
 import pytest
-from pay_api.models import EFTCredit as EFTCreditModel
 from pay_api.exceptions import BusinessException
 from pay_api.services.eft_service import EftService
 from pay_api.utils.enums import InvoiceStatus, PaymentMethod
+from pay_api.utils.errors import Error
 from tests.utilities.base_test import factory_invoice, factory_payment_account
 
 
@@ -66,22 +66,44 @@ def test_refund_eft_credits(session):
     credit2 = MagicMock(remaining_amount=4)
     credit3 = MagicMock(remaining_amount=3)
 
-    with patch.object(EFTCreditModel, 'find_by_short_name_id', return_value=[credit1, credit2, credit3]):
-        EftService._refund_eft_credits(1, 8)
+    with patch('pay_api.services.eft_service.EFTShortnames.get_eft_credits',
+               return_value=[credit1, credit2, credit3]), \
+         patch('pay_api.services.eft_service.EFTShortnames.get_eft_credit_balance', return_value=9):
+        EftService._refund_eft_credits(1, '8')
         assert credit1.remaining_amount == 0
         assert credit2.remaining_amount == 0
         assert credit3.remaining_amount == 1
 
         credit1.remaining_amount = 5
         credit2.remaining_amount = 5
 
-        EftService._refund_eft_credits(1, 7)
-        assert credit1.remaining_amount == 0
-        assert credit2.remaining_amount == 3
+        with patch('pay_api.services.eft_service.EFTShortnames.get_eft_credit_balance', return_value=10):
+            EftService._refund_eft_credits(1, '7')
+            assert credit1.remaining_amount == 0
+            assert credit2.remaining_amount == 3
 
         credit1.remaining_amount = 5
         credit2.remaining_amount = 2
 
-        EftService._refund_eft_credits(1, 1)
-        assert credit1.remaining_amount == 4
-        assert credit2.remaining_amount == 2
+        with patch('pay_api.services.eft_service.EFTShortnames.get_eft_credit_balance', return_value=7):
+            EftService._refund_eft_credits(1, '1')
+            assert credit1.remaining_amount == 4
+            assert credit2.remaining_amount == 2
+
+
+def test_refund_eft_credits_exceed_balance(session):
+    """Test refund amount exceeds eft_credit_balance."""
+    credit1 = MagicMock(remaining_amount=2)
+    credit2 = MagicMock(remaining_amount=4)
+    credit3 = MagicMock(remaining_amount=3)
+
+    with patch('pay_api.services.eft_service.EFTShortnames.get_eft_credits',
+               return_value=[credit1, credit2, credit3]), \
+         patch('pay_api.services.eft_service.EFTShortnames.get_eft_credit_balance', return_value=8), \
+         patch('flask.current_app.logger.error') as mock_error_logger:
+
+        with pytest.raises(BusinessException) as excinfo:
+            EftService._refund_eft_credits(1, '20')
+
+        assert excinfo.value.code == Error.INVALID_TRANSACTION.name
+        mock_error_logger.assert_called_with('Shortname 1 Refund amount exceed eft_credits remaining amount.')