def test_can_remove_previous_residue(self):
res = Residue(self.atom1, self.atom2, self.atom3)
previous_res = Mock(Residue)
res._previous = previous_res
previous_res._next = res
res.previous = None
self.assertIsNone(res._previous)
self.assertIsNone(previous_res._next)
def test_previous_residue_must_be_residue(self):
res = Residue(self.atom1, self.atom2, self.atom3)
mol = Mock(Molecule)
with self.assertRaises(TypeError):
res.previous = mol
def test_previous_res_cannot_be_self(self):
res = Residue(self.atom1, self.atom2, self.atom3)
with self.assertRaises(ValueError):
res.previous = res
def test_can_assign_previous(self):
res = Residue(self.atom1, self.atom2, self.atom3)
previous_res = Mock(Residue)
res.previous = previous_res
self.assertIs(res._previous, previous_res)
self.assertIs(previous_res._next, res)