Move FinTS client creation to seperate function

pycroft/lib/finance/fints.py

@@ -10,30 +10,37 @@
 from pycroft.model.finance import BankAccount
 
 
-def get_fints_transactions(
+def get_fints_client(
     *,
     product_id: str,
     user_id: int,
     secret_pin: str,
     bank_account: BankAccount,
+    **kwargs,
+) -> FinTS3Client:
+    return FinTS3Client(
+        bank_identifier=bank_account.routing_number,
+        user_id=user_id,
+        pin=secret_pin,
+        server=bank_account.fints_endpoint,
+        product_id=product_id,
+        **kwargs,
+    )
+
+
+def get_fints_transactions(
+    *,
     start_date: date,
     end_date: date,
-    FinTSClient: type[FinTS3Client] = FinTS3Client,
+    bank_account: BankAccount,
+    fints_client: FinTS3Client,
 ) -> tuple[list[MT940Transaction], list[StatementError]]:
     """Get the transactions from FinTS
 
     External service dependencies:
 
     - FinTS (:module:`pycroft.external_services.fints`)
     """
-    # login with fints
-    fints_client = FinTSClient(
-        bank_identifier=bank_account.routing_number,
-        user_id=user_id,
-        pin=secret_pin,
-        server=bank_account.fints_endpoint,
-        product_id=product_id,
-    )
     acc = next(
         (a for a in fints_client.get_sepa_accounts() if a.iban == bank_account.iban),
         None,

tests/external_services/test_fints.py

@@ -70,27 +70,48 @@ class BankAccountFactory(BankAccountFactory_):
 @pytest.fixture(scope="session")
 def default_transaction_args() -> dict:
     return {
-        "product_id": "1",
-        "user_id": 1,
-        "secret_pin": "123456",
         "start_date": today() - timedelta(days=30),
         "end_date": today(),
-        "FinTSClient": StubFintsClient,
     }
 
 
-def test_fints_connection(default_transaction_args):
+@pytest.fixture(scope="session")
+def default_fints_client_args() -> dict:
+    return {
+        "product_id": "1",
+        "user_id": 1,
+        "pin": "123456",
+    }
+
+
+def test_fints_connection(default_fints_client_args, default_transaction_args):
+    bank_account = BankAccountFactory.build(iban="DE61850503003120219540")
+    fints_client = StubFintsClient(
+        **default_fints_client_args,
+        bank_identifier=bank_account.routing_number,
+        server=bank_account.fints_endpoint,
+    )
+
     transactions, errors = get_fints_transactions(
         **default_transaction_args,
-        bank_account=BankAccountFactory.build(iban="DE61850503003120219540"),
+        bank_account=bank_account,
+        fints_client=fints_client,
     )
     assert transactions == []
     assert errors == []
 
 
-def test_transactions_unknown_iban(default_transaction_args):
+def test_transactions_unknown_iban(default_fints_client_args, default_transaction_args):
+    bank_account = BankAccountFactory.build()
+    fints_client = StubFintsClient(
+        **default_fints_client_args,
+        bank_identifier=bank_account.routing_number,
+        server=bank_account.fints_endpoint,
+    )
+
     with pytest.raises(KeyError, match="BankAccount with IBAN.*not found"):
         get_fints_transactions(
             **default_transaction_args,
-            bank_account=BankAccountFactory.build(),
+            bank_account=bank_account,
+            fints_client=fints_client,
         )

web/blueprints/finance/__init__.py

@@ -78,7 +78,7 @@
     get_last_import_date,
     get_last_membership_fee,
 )
-from pycroft.lib.finance.fints import get_fints_transactions
+from pycroft.lib.finance.fints import get_fints_transactions, get_fints_client
 from pycroft.lib.finance.matching import UserMatching, AccountMatching
 from pycroft.lib.mail import MemberNegativeBalance
 from pycroft.lib.user import encode_type2_user_id, user_send_mails
@@ -307,15 +307,20 @@ def display_form_response(
     if not form.validate():
         return display_form_response(imported)
 
+    fints_client = get_fints_client(
+        product_id=config.fints_product_id,
+        user_id=form.user.data,
+        secret_pin=form.secret_pin.data,
+        bank_account=bank_account,
+    )
+
     try:
         with flash_fints_errors():
             statement, errors = get_fints_transactions(
-                product_id=config.fints_product_id,
-                user_id=form.user.data,
-                secret_pin=form.secret_pin.data,
-                bank_account=bank_account,
                 start_date=form.start_date.data,
                 end_date=form.end_date.data,
+                bank_account=bank_account,
+                fints_client=fints_client,
             )
     except PycroftException:
         return display_form_response(imported)