def test_one_number():
assert add("1") == 1
def test_custom_delimiter():
assert add("//X\n1X2") == 3
def test_empty():
assert add("") == 0
def test_negative_numbers():
with pytest.raises(Exception):
add("-1,10")
def test_big_numbers():
assert add("1001,1000") == 1000
def test_newline_delim():
assert add("1\n2,3") == 6
def test_unknown_amount_of_numbers():
assert add("1,2,3,4,5") == 15
def test_two_numbers():
assert add("1,2") == 3