how to get the current balance (#183)

* example

* clarification

* fix

* fix

* tests

* test

* balance

* bump version

* comments

* using mock for empty balance entry test and clarification

* using mocks

* lint

* change order in __all__

Co-authored-by: Matin Tamizi <matin@users.noreply.github.com>

Author: felipao-mx

README.md

@@ -98,6 +98,17 @@ transfers = cuenca.Transfer.all(
 # the total number of succeeded transfers
 count = cuenca.Transfer.count(status=Status.succeeded)
 ```
+## Balance
+
+### Current balance
+```python
+import cuenca
+
+# balance is the amount in cents
+balance = cuenca.get_balance()
+
+```
+
 
 ## Api Keys
 

cuenca/__init__.py

@@ -19,10 +19,12 @@
     'UserLogin',
     'WhatsappTransfer',
     'configure',
+    'get_balance',
 ]
 
+from typing import cast
 
-from .http import session
+from .http import Session, session
 from .resources import (
     Account,
     ApiKey,
@@ -46,3 +48,8 @@
 from .version import __version__
 
 configure = session.configure
+
+
+def get_balance(session: Session = session) -> int:
+    balance_entry = cast('BalanceEntry', BalanceEntry.first(session=session))
+    return balance_entry.rolling_balance if balance_entry else 0

cuenca/version.py

@@ -1,3 +1,3 @@
-__version__ = '0.7.10'
+__version__ = '0.7.11'
 CLIENT_VERSION = __version__
 API_VERSION = '2020-03-19'

requirements-test.txt

@@ -6,5 +6,6 @@ mypy==0.910
 pytest==6.2.*
 pytest-cov==2.12.*
 pytest-vcr==1.0.*
+requests-mock==1.8.*
 types-freezegun
 types-requests

tests/test_cuenca.py

@@ -0,0 +1,51 @@
+import requests_mock  # type: ignore
+
+import cuenca
+
+
+def test_get_balance():
+    # It is the case when the user has transactions in the account
+    response_json = {
+        'items': [
+            {
+                'id': 'LE6xvD1ocHmSIu7MgzlC9woj',
+                'created_at': '2021-08-17T21:45:23.061000',
+                'user_id': 'US3zGWi1n852bTyqD1wCZ1ft',
+                'name': 'RESTAURANT BRASIL MEXICO DF CMXMX',
+                'amount': 1212,
+                'descriptor': '',
+                'rolling_balance': 7578889,
+                'type': 'debit',
+                'related_transaction_uri': '/card_transactions/CT3TA',
+                'funding_instrument_uri': '/cards/CA243qFpGLDAaPamCMYHhS0p',
+                'wallet_id': 'default',
+            }
+        ],
+        'next_page_uri': None,
+    }
+    with requests_mock.mock() as m:
+        m.get(
+            'https://sandbox.cuenca.com/balance_entries?limit=1',
+            status_code=200,
+            json=response_json,
+        )
+
+        balance = cuenca.get_balance()
+    assert balance == response_json['items'][0]['rolling_balance']
+
+
+def test_get_balance_before_first_transaction():
+    # When the user have no transactions at all
+    # balance_entries endpoint returns `items` as empty list.
+    # It means that its balance is Mx$0.00
+    response_json = {'items': [], 'next_page_uri': None}
+
+    with requests_mock.mock() as m:
+        m.get(
+            'https://sandbox.cuenca.com/balance_entries?limit=1',
+            status_code=200,
+            json=response_json,
+        )
+
+        balance = cuenca.get_balance()
+    assert balance == 0