def test_withEmptyString_shouldReturn0(self):
# with
expression = ""
# when
result = longest_parenthesis(expression)
# then
assert result == 0
def test_withUnMatchedParentheses_shouldReturn0(self):
# with
expression = "() (()) ("
# when
result = longest_parenthesis(expression)
# then
assert result == 0
def test_withFilledSinglePair_shouldReturnlength(self):
# with
expression = "(1 + 3 + 4 * 7)"
# when
result = longest_parenthesis(expression)
# then
assert result == len(expression)
def test_withComplexExpression_shouldReturn4(self):
# with
expression = "() (()) ()"
# when
result = longest_parenthesis(expression)
# then
assert result == 4
def test_withSinglePair_shouldReturn2(self):
# with
expression = "()"
# when
result = longest_parenthesis(expression)
# then
assert result == 2