def test_correct_exceptions_raised_on_contract_fail(self):
func = deal.pre(lambda x: x > 0)(lambda x: x)
with pytest.raises(deal.PreContractError):
func(-2)
func = deal.pre(lambda x: x > 0, message='TEST')(lambda x: x)
try:
func(-2)
except AssertionError as e:
assert e.args[0] == 'TEST'
func = deal.pre(lambda x: x > 0, exception=NameError)(lambda x: x)
with pytest.raises(NameError):
func(-2)
func = deal.pre(lambda x: x > 0,
exception=NameError('TEST'))(lambda x: x)
with pytest.raises(NameError):
func(-2)
try:
func(-2)
except NameError as e:
assert e.args[0] == 'TEST'
func = deal.pre(lambda x: x > 0, message='TEST',
exception=NameError)(lambda x: x)
with pytest.raises(NameError):
func(-2)
try:
func(-2)
except NameError as e:
assert e.args[0] == 'TEST'
def test_chain_all_contracts_fulfilled(correct, incorrect_min, incorrect_max):
func = deal.pre(lambda x: x < 10)(lambda x: x)
func = deal.pre(lambda x: x > 0)(func)
assert func(correct) == correct
with pytest.raises(deal.PreContractError):
func(incorrect_min)
with pytest.raises(deal.PreContractError):
func(incorrect_max)
def test_chain(self):
func = deal.pre(lambda x: x < 10)(lambda x: x)
func = deal.pre(lambda x: x > 0)(func)
with self.subTest(text='good'):
self.assertEqual(func(4), 4)
with self.subTest(text='error'):
with self.assertRaises(deal.PreContractError):
func(-2)
with self.subTest(text='error'):
with self.assertRaises(deal.PreContractError):
func(20)
def test_contract_state_switch_default_param():
func = deal.pre(lambda x: x > 0)(lambda x: x * 2)
deal.disable()
assert func(-2) == -4
deal.enable()
with pytest.raises(deal.PreContractError):
func(-2)
def test_contract_state_switch_custom_param():
func = deal.pre(lambda x: x > 0)(lambda x: x * 2)
deal.disable()
func(-2)
deal.enable()
with pytest.raises(deal.PreContractError):
func(-2)
def test_contract_state_switch_custom_param(self):
func = deal.pre(lambda x: x > 0, debug=True)(lambda x: x * 2)
deal.switch(debug=False)
func(-2)
deal.switch(debug=True)
with pytest.raises(deal.PreContractError):
func(-2)
def test_contract_state_switch_default_param(self):
func = deal.pre(lambda x: x > 0)(lambda x: x * 2)
deal.switch(main=False)
func(-2)
deal.switch(main=True)
with pytest.raises(deal.PreContractError):
func(-2)
def test_main(self):
func = pre(lambda x: x > 0)(lambda x: x)
with self.subTest(text='good'):
self.assertEqual(func(4), 4)
with self.subTest(text='error'):
with self.assertRaises(PreContractError):
func(-2)
def test_debug(self):
func = deal.pre(lambda x: x > 0, debug=True)(lambda x: x * 2)
deal.switch(debug=False)
with self.subTest(text='good'):
func(-2)
deal.switch(debug=True)
with self.subTest(text='error'):
with pytest.raises(deal.PreContractError):
func(-2)
def test_main(self):
func = deal.pre(lambda x: x > 0)(lambda x: x * 2)
deal.switch(main=False)
with self.subTest(text='good'):
func(-2)
deal.switch(main=True)
with self.subTest(text='error'):
with self.assertRaises(deal.PreContractError):
func(-2)
def test_raise_error_with_param_on_contract_failure(self):
func = deal.pre(lambda x: x > 0 or 'TEST')(lambda x: x)
assert func(4) == 4
with pytest.raises(deal.PreContractError):
func(-2)
try:
func(-2)
except deal.PreContractError as e:
assert e.args[0] == 'TEST'
def test_contract_returns_message():
func = deal.pre(lambda x: x > 0 or 'TEST')(lambda x: x)
assert func(4) == 4
with pytest.raises(deal.PreContractError):
func(-2)
try:
func(-2)
except deal.PreContractError as e:
assert e.args[0] == 'TEST'
def _test_validator(self, validator):
func = deal.pre(validator)(lambda x: x)
assert func(4) == 4
with pytest.raises(deal.PreContractError):
func(-2)
try:
func(-2)
except deal.PreContractError as e:
assert e.args[0] == 'TEST'
def test_source_get_chain():
sum_contract = deal.chain(
deal.pre(lambda a, b: a > 0),
deal.pre(lambda a, b: b > 0),
deal.post(lambda res: res > 0),
)
@sum_contract
def sum(a, b):
return a + b
with pytest.raises(deal.ContractError) as exc_info:
sum(-2, 3)
assert exc_info.value.source == 'a > 0'
with pytest.raises(deal.ContractError) as exc_info:
sum(2, -3)
assert exc_info.value.source == 'b > 0'
state.color = False
assert str(exc_info.value) == 'expected b > 0 (where a=2, b=-3)'
state.color = True
def test_error_returning(self):
func = deal.pre(lambda x: x > 0 or 'TEST')(lambda x: x)
with self.subTest(text='good'):
self.assertEqual(func(4), 4)
with self.subTest(text='error'):
with self.assertRaises(deal.PreContractError):
func(-2)
with self.subTest(text='error message'):
try:
func(-2)
except deal.PreContractError as e:
self.assertEqual(e.args[0], 'TEST')
def _test_validator(self, validator):
func = deal.pre(validator)(lambda x: x)
with self.subTest(text='good'):
self.assertEqual(func(4), 4)
with self.subTest(text='error'):
with self.assertRaises(deal.PreContractError):
func(-2)
with self.subTest(text='error message'):
try:
func(-2)
except deal.PreContractError as e:
self.assertEqual(e.args[0], 'TEST')
def test_django_style_without_attr(self):
class Validator:
def __init__(self, x):
self.x = x
def is_valid(self):
if self.x <= 0:
return False
return True
func = deal.pre(Validator)(lambda x: x)
with self.subTest(text='good'):
self.assertEqual(func(4), 4)
with self.subTest(text='error'):
with self.assertRaises(deal.PreContractError):
func(-2)
def test_exception_hook(capsys):
pre_path = str(Path('deal', '_decorators', 'pre.py'))
f = deal.pre(lambda x: x > 0)(lambda x: x)
with pytest.raises(deal.PreContractError) as exc_info:
f(-2)
# custom hook is registered
assert sys.excepthook is exception_hook
# the default hook shows the full traceback
_excepthook(exc_info.type, exc_info.value, exc_info.tb)
captured = capsys.readouterr()
assert captured.out == ''
assert pre_path in captured.err
# the custom hook hides deal from the traceback
exception_hook(exc_info.type, exc_info.value, exc_info.tb)
captured = capsys.readouterr()
assert captured.out == ''
# the hook doesn't work on python 3.6 and below
if sys.version_info[:2] >= (3, 7):
assert pre_path not in captured.err
def test_init(self):
with self.subTest(text='init has not raised any exceptions'):
func = deal.pre(lambda x: x > 0)
with self.subTest(text='validator'):
func = deal.pre(lambda x: x > 0)(lambda x: x)
with self.assertRaises(deal.PreContractError):
func(-2)
with self.subTest(text='message'):
func = deal.pre(lambda x: x > 0, message='TEST')(lambda x: x)
try:
func(-2)
except AssertionError as e:
self.assertEqual(e.args[0], 'TEST')
with self.subTest(text='exception'):
func = deal.pre(lambda x: x > 0, exception=NameError)(lambda x: x)
with self.assertRaises(NameError):
func(-2)
with self.subTest(text='exception with name'):
func = deal.pre(lambda x: x > 0,
exception=NameError('TEST'))(lambda x: x)
with self.subTest(text='exception/exception'):
with self.assertRaises(NameError):
func(-2)
with self.subTest(text='exception/message'):
try:
func(-2)
except NameError as e:
self.assertEqual(e.args[0], 'TEST')
with self.subTest(text='exception+message'):
func = deal.pre(lambda x: x > 0,
message='TEST',
exception=NameError)(lambda x: x)
with self.subTest(text='exception+message/exception'):
with self.assertRaises(NameError):
func(-2)
with self.subTest(text='exception+message/message'):
try:
func(-2)
except NameError as e:
self.assertEqual(e.args[0], 'TEST')
def test_django_style(self):
class Validator(object):
def __init__(self, x):
self.x = x
def is_valid(self):
if self.x <= 0:
self.errors = 'TEST'
return False
return True
func = pre(Validator)(lambda x: x)
with self.subTest(text='good'):
self.assertEqual(func(4), 4)
with self.subTest(text='error'):
with self.assertRaises(PreContractError):
func(-2)
with self.subTest(text='error message'):
try:
func(-2)
except PreContractError as e:
self.assertEqual(e.args[0], 'TEST')
def test_pre_contract_fulfilled(self, correct, incorrect):
func = deal.pre(lambda x: x > 0)(lambda x: x)
assert func(correct) == correct
with pytest.raises(deal.PreContractError):
func(incorrect)
