How to mock datetime.today()
I was thinking about how to achieve it some days ago. There's a method that uses today's date to choose which transactions should be returned and I have no idea how to mock this!
Well, after some research, here it is:
views.py
from datetime import datetime
... # more code that uses datetime.today()
tests.py
Pay attention to mock.patch, we're overriding datetime module only inside of views.py!
from unittest import mock
... #more imports
@mock.patch('transactions.views.datetime', side_effect=lambda *args, **kw: date(*args, **kw))
def test_returns_only_from_current_month_by_default(self, mock_date):
'''
Returns only transactions from current month. Considering today is 15/02/2017
'''
mocked_today = datetime.datetime(2017, 2, 15)
mock_date.today.return_value = mocked_today
#old transactions
self.create_transaction(value=self.value, due_date=datetime.date(2016, 12, 1))
self.create_transaction(value=self.value, due_date=datetime.date(2017, 1, 1))
#current month
self.create_transaction(value=self.value, due_date=datetime.date(2017, 2, 1))
self.create_transaction(value=self.value, due_date=datetime.date(2017, 2, 7))
self.create_transaction(value=self.value, due_date=datetime.date(2017, 2, 8))
self.create_transaction(value=self.value, due_date=datetime.date(2017, 2, 14))
response = self.client.get(self.url)
self.assertEqual(response.status_code, status.HTTP_200_OK)
self.assertEqual(len(response.data), 4)