def check(self, fn):
assert self._test_cases, "Oops, someone forgot to write test cases."
for args, expected in self._test_cases:
orig_args = args
# Wrap in tuple if necessary
if not isinstance(args, tuple):
args = args,
# XXX: ugh, need to guard against mutation :(
# Beware of more exotic mutable types (which lack a copy method, or which
# require a deep copy). Maybe this shouldn't be handled at this level -
# maybe cleaner to have a method that can repeatedly spit out fresh lists
# of test cases every time it's called, rather than having test cases be
# a static attribute.
args = [(arg.copy() if hasattr(arg, 'copy') else arg)
for arg in args]
orig_args = [(arg.copy() if hasattr(arg, 'copy') else arg)
for arg in args]
try:
actual = fn(*args)
except Exception as e:
raise UserlandExceptionIncorrect(e, orig_args)
assert not (actual is None and expected is not None), (
"Got a return value of `None`"
" given {}, but expected a value of type `{}`. (Did you forget a `return` statement?)"
).format(utils.format_args(fn, orig_args),
type(expected).__name__)
assert actual == expected, (
"Expected return value of `{}` given {},"
" but got `{}` instead.").format(
repr(expected), utils.format_args(fn, orig_args),
repr(actual))
def check(self, *args):
expected = self.canonical_prepared(*args)
actual = self.ill_prepared(*args)
assert actual != expected, ("Given {}, `prepared_for_weather` returned"
" `{}`. But I think that's correct. (We want inputs that lead to"
" an incorrect result from `prepared_for_weather`.)").format(
format_args(self.ill_prepared, args),
repr(actual),
)