class NestedObjectsTests(TestCase):
"""
Tests for ``NestedObject`` utility collection.
"""
def setUp(self):
self.n = NestedObjects(using=DEFAULT_DB_ALIAS)
self.objs = [Count.objects.create(num=i) for i in range(5)]
def _check(self, target):
self.assertEqual(self.n.nested(lambda obj: obj.num), target)
def _connect(self, i, j):
self.objs[i].parent = self.objs[j]
self.objs[i].save()
def _collect(self, *indices):
self.n.collect([self.objs[i] for i in indices])
def test_unrelated_roots(self):
self._connect(2, 1)
self._collect(0)
self._collect(1)
self._check([0, 1, [2]])
def test_siblings(self):
self._connect(1, 0)
self._connect(2, 0)
self._collect(0)
self._check([0, [1, 2]])
def test_non_added_parent(self):
self._connect(0, 1)
self._collect(0)
self._check([0])
def test_cyclic(self):
self._connect(0, 2)
self._connect(1, 0)
self._connect(2, 1)
self._collect(0)
self._check([0, [1, [2]]])
def test_queries(self):
self._connect(1, 0)
self._connect(2, 0)
# 1 query to fetch all children of 0 (1 and 2)
# 1 query to fetch all children of 1 and 2 (none)
# Should not require additional queries to populate the nested graph.
self.assertNumQueries(2, self._collect, 0)
def setUp(self):
self.n = NestedObjects(using=DEFAULT_DB_ALIAS)
self.objs = [Count.objects.create(num=i) for i in range(5)]
