add unittests for accounting service

testing/unittests/AccountingServiceTests.py

@@ -0,0 +1,113 @@
+import unittest
+from datetime import datetime
+from unittest.mock import MagicMock, AsyncMock
+
+from src.ez_lan_manager.services.AccountingService import AccountingService, InsufficientFundsError
+from src.ez_lan_manager.types.Transaction import Transaction
+
+
+class AccountingServiceTests(unittest.IsolatedAsyncioTestCase):
+    def setUp(self) -> None:
+        self.mock_database_service = MagicMock()
+        self.mock_database_service.add_transaction = AsyncMock()
+        self.accounting_service = AccountingService(self.mock_database_service)
+
+
+    def test_importing_unit_under_test_works(self) -> None:
+        """
+        This test asserts that the object produced in setUp is AccountingService object,
+        if that fails, there is no reason to execute any other test.
+        """
+        self.assertIsInstance(self.accounting_service, AccountingService)
+
+    def test_making_string_from_euro_value_works_correctly(self) -> None:
+        test_value = 13466
+        expected_result = "134.66 €"
+        self.assertEqual(expected_result, AccountingService.make_euro_string_from_int(test_value))
+
+    def test_making_euro_string_from_negative_value_works_correctly(self) -> None:
+        test_value = -99741
+        expected_result = "-997.41 €"
+        self.assertEqual(expected_result, AccountingService.make_euro_string_from_int(test_value))
+
+    def test_making_euro_string_from_less_than_ten_cents_works_correctly(self) -> None:
+        test_value = 4
+        expected_result = "0.04 €"
+        self.assertEqual(expected_result, AccountingService.make_euro_string_from_int(test_value))
+
+    async def test_get_balance_correctly_adds_up_transactions(self) -> None:
+        self.mock_database_service.get_all_transactions_for_user = AsyncMock(return_value=[
+            Transaction(
+                user_id=0,
+                value=5,
+                is_debit=True,
+                reference="",
+                transaction_date=datetime.now()
+            ),
+            Transaction(
+                user_id=0,
+                value=99,
+                is_debit=False,
+                reference="",
+                transaction_date=datetime.now()
+            ),
+            Transaction(
+                user_id=0,
+                value=101,
+                is_debit=False,
+                reference="",
+                transaction_date=datetime.now()
+            ),
+            Transaction(
+                user_id=0,
+                value=77,
+                is_debit=True,
+                reference="",
+                transaction_date=datetime.now()
+            ),
+        ])
+        expected_result = 118
+        actual_result = await self.accounting_service.get_balance(0)
+
+        self.assertEqual(expected_result, actual_result)
+
+    async def test_trying_to_remove_more_than_is_on_account_balance_raises_exception(self) -> None:
+        user_balance = 100
+        balance_to_remove = 101
+        self.mock_database_service.get_all_transactions_for_user = AsyncMock(return_value=[
+            Transaction(
+                user_id=0,
+                value=user_balance,
+                is_debit=False,
+                reference="",
+                transaction_date=datetime.now()
+            )
+        ])
+
+        with self.assertRaises(InsufficientFundsError):
+            await self.accounting_service.remove_balance(0, balance_to_remove, "TestRef")
+
+    async def test_trying_to_remove_less_than_is_on_account_balance_spawns_correct_transaction(self) -> None:
+        user_balance = 101
+        balance_to_remove = 100
+        reference = "Yey, a reference"
+
+        self.mock_database_service.get_all_transactions_for_user = AsyncMock(return_value=[
+            Transaction(
+                user_id=123,
+                value=user_balance,
+                is_debit=False,
+                reference="",
+                transaction_date=datetime.now()
+            )
+        ])
+
+        await self.accounting_service.remove_balance(123, balance_to_remove, reference)
+
+        # Async unittest API is still not perfect for retrieving a call value. So we force it to hand it over.
+        last_transaction: Transaction = self.mock_database_service.add_transaction.call_args_list[-1].args[-1]
+
+        self.assertEqual(123, last_transaction.user_id)
+        self.assertEqual(balance_to_remove, last_transaction.value)
+        self.assertEqual(True, last_transaction.is_debit)
+        self.assertEqual(reference, last_transaction.reference)