def test_can_remove_next_residue(self):
res = Residue(self.atom1, self.atom2, self.atom3)
next_res = Mock(Residue)
res._next = next_res
next_res._previous = res
res.next = None
self.assertIsNone(res._next)
self.assertIsNone(next_res._previous)
def test_next_res_cannot_be_self(self):
res = Residue(self.atom1, self.atom2, self.atom3)
with self.assertRaises(ValueError):
res.next = res
def test_next_residue_must_be_residue(self):
res = Residue(self.atom1, self.atom2, self.atom3)
mol = Mock(Molecule)
with self.assertRaises(TypeError):
res.next = mol
def test_can_assign_next(self):
res = Residue(self.atom1, self.atom2, self.atom3)
next_res = Mock(Residue)
res.next = next_res
self.assertIs(res._next, next_res)
self.assertIs(next_res._previous, res)