def test_iter(capsys):
opt: Optional[int] = option.some(55)
option.iter(print, opt)
captured = capsys.readouterr()
assert captured.out == "55\n"
option.iter(print, option.none())
captured = capsys.readouterr()
assert captured.out == ""
def test_equal():
opt1 = option.some(10)
opt2 = option.some(10)
opt3 = option.some(55)
opt4 = option.none()
compare: Callable[[int, int], bool] = lambda x, y: x == y
assert option.equal(compare, opt1, opt2)
assert option.equal(compare, opt1, opt3) == False
assert option.equal(compare, opt1, opt4) == False
assert option.equal(compare, opt4, None)
def test_compare():
opt1 = option.some(10)
opt2 = option.some(10)
opt3 = option.some(55)
opt4 = option.none()
compare: Callable[[int, int], int] = lambda x, y: x - y
assert option.compare(compare, opt1, opt2) == 0
assert option.compare(compare, opt1, opt3) < 0
assert option.compare(compare, opt3, opt1) > 0
assert option.compare(compare, opt1, opt4) > 0
assert option.compare(compare, opt1, opt4) > 0
assert option.compare(compare, opt4, None) == 0
def test_is_some():
assert option.is_some(option.some(55)) == True
assert option.is_some(option.none()) == False
def test_fold():
opt: Optional[int] = option.some(55)
nopt: Optional[int] = option.none()
assert option.fold(-1, lambda n: n * 2, opt) == 110
assert option.fold(-1, lambda n: n * 2, nopt) == -1
def test_bind():
opt = option.some("Dave")
nopt = option.none()
assert option.bind(opt, str.upper) == "DAVE"
assert option.bind(nopt, str.upper) == None
def test_map():
opt: Optional[int] = option.some(55)
assert option.map(str, opt) == "55"
assert option.map(lambda n: n / 2, opt) == 27.5
assert option.map(str, option.none()) == None
def test_get():
opt = option.some("Dave")
nopt = option.none()
assert option.get(opt) == "Dave"
with pytest.raises(option.InvalidArgument):
assert option.get(nopt)
def test_value():
opt = option.some(5)
nopt = option.none()
assert option.value(1, opt) == 5
assert option.value(1, nopt) == 1
def test_none():
assert option.none() == None
def test_to_sequence():
opt = option.some(55)
assert option.to_seq(opt) == [55]
assert option.to_seq(option.none()) == []
def test_to_list():
opt = option.some(55)
assert option.to_list(opt) == [55]
assert option.to_list(option.none()) == []