def test_queryset_where_clauses(self):
queryset = CursorQueryset(model=ExampleModel).all()
cursor1 = queryset[:self.PAGE_SIZE].cursor()
queryset1 = queryset.from_cursor(cursor1)
cursor2 = queryset1[self.PAGE_SIZE:2 * self.PAGE_SIZE].cursor()
queryset2 = queryset.from_cursor(cursor2)
self.assertEqual(
len(queryset1.query.where.children),
len(queryset2.query.where.children),
"Cursor generated querysets had different where clause lengths"
)
def test_queryset_consistent_with_data_insert(self):
"""
Ensures that a cursor returned from a queryset stays fixed when new
items are inserted.
"""
queryset = CursorQueryset(model=ExampleModel).order_by('count_field')
cursor = queryset[:self.PAGE_SIZE].cursor()
assert cursor.token
expected = set([
x.pk for x in queryset[:self.PAGE_SIZE]
])
first = queryset[0]
# Now add some instances that would change the indexing
for i in range(10):
ExampleModelFactory.create(count_field=first.count_field - 1)
queryset2 = queryset.from_cursor(cursor)
actual = set([x.pk for x in queryset2[:self.PAGE_SIZE]])
self.assertSetEqual(expected, actual)