django/tests/db_functions/test_window.py

40 lines
1.5 KiB
Python

from django.db.models.functions import Lag, Lead, NthValue, Ntile
from django.test import SimpleTestCase
class ValidationTests(SimpleTestCase):
def test_nth_negative_nth_value(self):
msg = 'NthValue requires a positive integer as for nth'
with self.assertRaisesMessage(ValueError, msg):
NthValue(expression='salary', nth=-1)
def test_nth_null_expression(self):
msg = 'NthValue requires a non-null source expression'
with self.assertRaisesMessage(ValueError, msg):
NthValue(expression=None)
def test_lag_negative_offset(self):
msg = 'Lag requires a positive integer for the offset'
with self.assertRaisesMessage(ValueError, msg):
Lag(expression='salary', offset=-1)
def test_lead_negative_offset(self):
msg = 'Lead requires a positive integer for the offset'
with self.assertRaisesMessage(ValueError, msg):
Lead(expression='salary', offset=-1)
def test_null_source_lead(self):
msg = 'Lead requires a non-null source expression'
with self.assertRaisesMessage(ValueError, msg):
Lead(expression=None)
def test_null_source_lag(self):
msg = 'Lag requires a non-null source expression'
with self.assertRaisesMessage(ValueError, msg):
Lag(expression=None)
def test_negative_num_buckets_ntile(self):
msg = 'num_buckets must be greater than 0'
with self.assertRaisesMessage(ValueError, msg):
Ntile(num_buckets=-1)