def test_evaluate_divide_by_zero(self):
"""
In case of divide by zero it should return None for that operator node
"""
input_string_list = ('2 / 0', '1 + (2 / 0)')
for input_string in input_string_list:
root_node = build_tree(input_string)
with self.assertRaises(EvaluationError):
evaluate(root_node)
def test_evaluate_non_digit_token(self):
input_string = 'A + (B * C)'
root_node = build_tree(input_string)
with self.assertRaises(EvaluationError):
evaluate(root_node)
def test_evaluate(self):
for input_string_tup in self.input_string_list:
input_string, expected_result = input_string_tup
root_node = build_tree(input_string)
self.assertEqual(evaluate(root_node), expected_result)