def test_multiple_empty(self):
"""
Empty list/tuple for validator is the same as None.
"""
C1 = make_class("C", {"x": attr.ib(validator=[])})
C2 = make_class("C", {"x": attr.ib(validator=None)})
assert inspect.getsource(C1.__init__) == inspect.getsource(C2.__init__)
def test_no_init_order(self):
"""
If an attribute is `init=False`, it's legal to come after a mandatory
attribute.
"""
make_class("C", {
"a": attr(default=Factory(list)),
"b": attr(init=False),
})
def test_no_init_order(self, slots, frozen):
"""
If an attribute is `init=False`, it's legal to come after a mandatory
attribute.
"""
make_class("C", {
"a": attr.ib(default=Factory(list)),
"b": attr.ib(init=False),
}, slots=slots, frozen=frozen)
def test_catches_wrong_attrs_type(self):
"""
Raise `TypeError` if an invalid type for attrs is passed.
"""
with pytest.raises(TypeError) as e:
make_class("C", object())
assert (
"attrs argument must be a dict or a list.",
) == e.value.args
def test_repr_str(self):
"""
Trying to add a `__str__` without having a `__repr__` raises a
ValueError.
"""
with pytest.raises(ValueError) as ei:
make_class("C", {}, repr=False, str=True)
assert (
"__str__ can only be generated if a __repr__ exists.",
) == ei.value.args
def test_bases(self):
"""
Parameter bases default to (object,) and subclasses correctly
"""
class D(object):
pass
cls = make_class("C", {})
assert cls.__mro__[-1] == object
cls = make_class("C", {}, bases=(D,))
assert D in cls.__mro__
assert isinstance(cls(), D)
def test_multiple_validators(self):
"""
If a list is passed as a validator, all of its items are treated as one
and must pass.
"""
def v1(_, __, value):
if value == 23:
raise TypeError("omg")
def v2(_, __, value):
if value == 42:
raise ValueError("omg")
C = make_class("C", {"x": attr.ib(validator=[v1, v2])})
validate(C(1))
with pytest.raises(TypeError) as e:
C(23)
assert "omg" == e.value.args[0]
with pytest.raises(ValueError) as e:
C(42)
assert "omg" == e.value.args[0]
def test_success(self):
"""
If the validator suceeds, nothing gets raised.
"""
C = make_class("C", {"x": attr(validator=lambda *a: None),
"y": attr()})
validate(C(1, 2))
def test_hash(self):
"""
If `hash` is False, ignore that attribute.
"""
C = make_class("C", {"a": attr(hash=False), "b": attr()})
assert hash(C(1, 2)) == hash(C(2, 2))
def _create_hyp_class(attrs):
"""
A helper function for Hypothesis to generate attrs classes.
"""
return make_class(
"HypClass", dict(zip(gen_attr_names(), attrs))
)
def test_enforces_type(self):
"""
The `hash` argument to both attrs and attrib must be None, True, or
False.
"""
exc_args = ("Invalid value for hash. Must be True, False, or None.",)
with pytest.raises(TypeError) as e:
make_class("C", {}, hash=1),
assert exc_args == e.value.args
with pytest.raises(TypeError) as e:
make_class("C", {"a": attr(hash=1)}),
assert exc_args == e.value.args
def test_empty_metadata_singleton(self, list_of_attrs):
"""
All empty metadata attributes share the same empty metadata dict.
"""
C = make_class("C", dict(zip(gen_attr_names(), list_of_attrs)))
for a in fields(C)[1:]:
assert a.metadata is fields(C)[0].metadata
def test_cmp(self):
"""
If `cmp` is False, ignore that attribute.
"""
C = make_class("C", {"a": attr(cmp=False), "b": attr()})
assert C(1, 2) == C(2, 2)
def test_attr_args(self):
"""
attributes_arguments are passed to attributes
"""
C = make_class("C", ["x"], repr=False)
assert repr(C(1)).startswith("<tests.test_make.C object at 0x")
def test_repr(self):
"""
If `repr` is False, ignore that attribute.
"""
C = make_class("C", {"a": attr(repr=False), "b": attr()})
assert "C(b=2)" == repr(C(1, 2))
def simple_class(cmp=False, repr=False, hash=False, slots=False):
"""
Return a new simple class.
"""
return make_class(
"C", ["a", "b"],
cmp=cmp, repr=repr, hash=hash, init=True, slots=slots
)
def test_frozen(self):
"""
Converters circumvent immutability.
"""
C = make_class("C", {
"x": attr.ib(converter=lambda v: int(v)),
}, frozen=True)
C("1")
def test_missing_sys_getframe(self, monkeypatch):
"""
`make_class()` does not fail when `sys._getframe()` is not available.
"""
monkeypatch.delattr(sys, '_getframe')
C = make_class("C", ["x"])
assert 1 == len(C.__attrs_attrs__)
def test_hash_attribute(self, slots):
"""
If `hash` is False on an attribute, ignore that attribute.
"""
C = make_class("C", {"a": attr(hash=False), "b": attr()},
slots=slots, hash=True)
assert hash(C(1, 2)) == hash(C(2, 2))
def test_clean_class(self, slots):
"""
Attribute definitions do not appear on the class body.
"""
C = make_class("C", ["x"], slots=slots)
x = getattr(C, "x", None)
assert not isinstance(x, _CountingAttr)
def test_repr_uninitialized_member(self):
"""
repr signals unset attributes
"""
C = make_class("C", {
"a": attr.ib(init=False),
})
assert "C(a=NOTHING)" == repr(C())
def test_convert(self):
"""
Return value of convert is used as the attribute's value.
"""
C = make_class("C", {"x": attr(convert=lambda v: v + 1),
"y": attr()})
c = C(1, 2)
assert c.x == 2
assert c.y == 2
def test_validator_others(self):
"""
Does not interfere when setting non-attrs attributes.
"""
C = make_class("C", {"a": attr("a", validator=instance_of(int))})
i = C(1)
i.b = "foo"
assert 1 == i.a
assert "foo" == i.b
def test_init(self):
"""
If `init` is False, ignore that attribute.
"""
C = make_class("C", {"a": attr(init=False), "b": attr()})
with pytest.raises(TypeError) as e:
C(a=1, b=2)
msg = e.value if PY26 else e.value.args[0]
assert "__init__() got an unexpected keyword argument 'a'" == msg
def test_cmp(self, slots):
"""
If `cmp` is False, ignore that attribute.
"""
C = make_class("C", {
"a": attr.ib(cmp=False),
"b": attr.ib()
}, slots=slots)
assert C(1, 2) == C(2, 2)
def test_convert_property(self, val, init):
"""
Property tests for attributes with convert.
"""
C = make_class("C", {"y": attr(),
"x": attr(init=init, default=val,
convert=lambda v: v + 1),
})
c = C(2)
assert c.x == val + 1
assert c.y == 2
def test_factory_takes_self(self):
"""
If takes_self on factories is True, self is passed.
"""
C = make_class("C", {"x": attr(default=Factory(
(lambda self: self), takes_self=True
))})
i = C()
assert i is i.x
def test_not_none_metadata(self, list_of_attrs):
"""
Non-empty metadata attributes exist as fields after ``@attr.s``.
"""
C = make_class("C", dict(zip(gen_attr_names(), list_of_attrs)))
assert len(fields(C)) > 0
for cls_a, raw_a in zip(fields(C), list_of_attrs):
assert cls_a.metadata != {}
assert cls_a.metadata == raw_a.metadata
def test_simple(self, ls):
"""
Passing a list of strings creates attributes with default args.
"""
C1 = make_class("C1", ls(["a", "b"]))
@attr.s
class C2(object):
a = attr.ib()
b = attr.ib()
assert C1.__attrs_attrs__ == C2.__attrs_attrs__
def test_dict(self):
"""
Passing a dict of name: _CountingAttr creates an equivalent class.
"""
C1 = make_class("C1", {"a": attr(default=42), "b": attr(default=None)})
@attributes
class C2(object):
a = attr(default=42)
b = attr(default=None)
assert C1.__attrs_attrs__ == C2.__attrs_attrs__
def test_factory_takes_self(self):
"""
If takes_self on factories is True, self is passed.
"""
C = make_class(
"C",
{
"x":
attr.ib(default=Factory((lambda self: self), takes_self=True))
},
)
i = C()
assert i is i.x
def test_hash_attribute(self, slots):
"""
If `hash` is False on an attribute, ignore that attribute.
"""
C = make_class(
"C",
{
"a": attr.ib(hash=False),
"b": attr.ib()
},
slots=slots,
hash=True,
)
assert hash(C(1, 2)) == hash(C(2, 2))
def test_propagates(self):
"""
The exception of the validator is handed through.
"""
def raiser(_, __, value):
if value == 42:
raise FloatingPointError
C = make_class("C", {"x": attr.ib(validator=raiser)})
i = C(1)
i.x = 42
with pytest.raises(FloatingPointError):
validate(i)
def test_init(self, slots, frozen):
"""
If `init` is False, ignore that attribute.
"""
C = make_class("C", {
"a": attr.ib(init=False),
"b": attr.ib()
},
slots=slots,
frozen=frozen)
with pytest.raises(TypeError) as e:
C(a=1, b=2)
assert ("__init__() got an unexpected keyword argument 'a'" ==
e.value.args[0])
def test_dict(self):
"""
Passing a dict of name: _CountingAttr creates an equivalent class.
"""
C1 = make_class("C1", {
"a": attr.ib(default=42),
"b": attr.ib(default=None),
})
@attr.s
class C2(object):
a = attr.ib(default=42)
b = attr.ib(default=None)
assert C1.__attrs_attrs__ == C2.__attrs_attrs__
def test_validator_others(self, slots):
"""
Does not interfere when setting non-attrs attributes.
"""
C = make_class("C", {"a": attr.ib("a", validator=instance_of(int))},
slots=slots)
i = C(1)
assert 1 == i.a
if not slots:
i.b = "foo"
assert "foo" == i.b
else:
with pytest.raises(AttributeError):
i.b = "foo"
def test_convert_factory_property(self, val, init):
"""
Property tests for attributes with convert, and a factory default.
"""
C = make_class("C", ordered_dict([
("y", attr.ib()),
("x", attr.ib(
init=init,
default=Factory(lambda: val),
converter=lambda v: v + 1
)),
]))
c = C(2)
assert c.x == val + 1
assert c.y == 2
def test_convert_before_validate(self):
"""
Validation happens after conversion.
"""
def validator(inst, attr, val):
raise RuntimeError("foo")
C = make_class(
"C",
{
"x": attr.ib(validator=validator, converter=lambda v: 1 / 0),
"y": attr.ib(),
},
)
with pytest.raises(ZeroDivisionError):
C(1, 2)
def test_convert_property(self, val, init):
"""
Property tests for attributes using converter.
"""
C = make_class(
"C",
{
"y": attr.ib(),
"x": attr.ib(init=init, default=val,
converter=lambda v: v + 1),
},
)
c = C(2)
assert c.x == val + 1
assert c.y == 2
def test_convert_factory_property(self, val, init):
"""
Property tests for attributes with convert, and a factory default.
"""
C = make_class(
"C", {
"y":
attr(),
"x":
attr(init=init,
default=Factory(lambda: val),
convert=lambda v: v + 1),
})
c = C(2)
assert c.x == val + 1
assert c.y == 2
def test_validator_slots(self):
"""
If a validator is passed, call it with the preliminary instance, the
Attribute, and the argument.
"""
class VException(Exception):
pass
def raiser(*args):
raise VException(*args)
C = make_class("C", {"a": attr("a", validator=raiser)}, slots=True)
with pytest.raises(VException) as e:
C(42)
assert (fields(C)[0], 42,) == e.value.args[1:]
assert isinstance(e.value.args[0], C)
def simple_classes(draw, slots=None, frozen=None, private_attrs=None):
"""
A strategy that generates classes with default non-attr attributes.
For example, this strategy might generate a class such as:
@attr.s(slots=True, frozen=True)
class HypClass:
a = attr.ib(default=1)
_b = attr.ib(default=None)
c = attr.ib(default='text')
_d = attr.ib(default=1.0)
c = attr.ib(default={'t': 1})
By default, all combinations of slots and frozen classes will be generated.
If `slots=True` is passed in, only slots classes will be generated, and
if `slots=False` is passed in, no slot classes will be generated. The same
applies to `frozen`.
By default, some attributes will be private (i.e. prefixed with an
underscore). If `private_attrs=True` is passed in, all attributes will be
private, and if `private_attrs=False`, no attributes will be private.
"""
attrs = draw(list_of_attrs)
frozen_flag = draw(st.booleans()) if frozen is None else frozen
slots_flag = draw(st.booleans()) if slots is None else slots
if private_attrs is None:
attr_names = maybe_underscore_prefix(gen_attr_names())
elif private_attrs is True:
attr_names = ('_' + n for n in gen_attr_names())
elif private_attrs is False:
attr_names = gen_attr_names()
cls_dict = dict(zip(attr_names, attrs))
post_init_flag = draw(st.booleans())
if post_init_flag:
def post_init(self):
pass
cls_dict["__attrs_post_init__"] = post_init
return make_class(
"HypClass",
cls_dict,
slots=slots_flag,
frozen=frozen_flag,
)
def test_hash_mirrors_eq(self, eq):
"""
If `hash` is None, the hash generation mirrors `eq`.
"""
C = make_class("C", {"a": attr.ib()}, eq=eq, frozen=True)
i = C(1)
assert i == i
assert hash(i) == hash(i)
if eq:
assert C(1) == C(1)
assert hash(C(1)) == hash(C(1))
else:
assert C(1) != C(1)
assert hash(C(1)) != hash(C(1))
def test_validator(self):
"""
If a validator is passed, call it with the Attribute and the argument.
"""
class VException(Exception):
pass
def raiser(*args):
raise VException(args)
C = make_class("C", {"a": attr("a", validator=raiser)})
with pytest.raises(VException) as e:
C(42)
assert ((
C.a,
42,
), ) == e.value.args
def test_no_init_default(self, slots, frozen):
"""
If `init` is False but a Factory is specified, don't allow passing that
argument but initialize it anyway.
"""
C = make_class("C", {
"_a": attr(init=False, default=42),
"_b": attr(init=False, default=Factory(list)),
"c": attr()
}, slots=slots, frozen=frozen)
with pytest.raises(TypeError):
C(a=1, c=2)
with pytest.raises(TypeError):
C(b=1, c=2)
i = C(23)
assert (42, [], 23) == (i._a, i._b, i.c)
def test_hash_mirrors_cmp(self, cmp):
"""
If `hash` is None, the hash generation mirrors `cmp`.
"""
C = make_class("C", {"a": attr.ib()}, cmp=cmp, frozen=True)
i = C(1)
assert i == i
assert hash(i) == hash(i)
if cmp:
assert C(1) == C(1)
assert hash(C(1)) == hash(C(1))
else:
assert C(1) != C(1)
assert hash(C(1)) != hash(C(1))
def test_run_validators(self):
"""
Setting `_run_validators` to False prevents validators from running.
"""
_config._run_validators = False
obj = object()
def raiser(_, __, ___):
raise Exception(obj)
C = make_class("C", {"x": attr(validator=raiser)})
assert 1 == C(1).x
_config._run_validators = True
with pytest.raises(Exception) as e:
C(1)
assert (obj,) == e.value.args
def test_metadata_present(self, list_of_attrs):
"""
Assert dictionaries are copied and present.
"""
C = make_class("C", dict(zip(gen_attr_names(), list_of_attrs)))
for hyp_attr, class_attr in zip(list_of_attrs, fields(C)):
if hyp_attr.metadata is None:
# The default is a singleton empty dict.
assert class_attr.metadata is not None
assert len(class_attr.metadata) == 0
else:
assert hyp_attr.metadata == class_attr.metadata
# Once more, just to assert getting items and iteration.
for k in class_attr.metadata:
assert hyp_attr.metadata[k] == class_attr.metadata[k]
assert (
hyp_attr.metadata.get(k) == class_attr.metadata.get(k))
def simple_class(cmp=False,
repr=False,
hash=False,
str=False,
slots=False,
frozen=False):
"""
Return a new simple class.
"""
return make_class(
"C",
["a", "b"],
cmp=cmp,
repr=repr,
hash=hash,
init=True,
slots=slots,
str=str,
frozen=frozen,
)
def simple_classes(draw, slots=None, frozen=None):
"""A strategy that generates classes with default non-attr attributes.
For example, this strategy might generate a class such as:
@attr.s(slots=True, frozen=True)
class HypClass:
a = attr.ib(default=1)
b = attr.ib(default=None)
c = attr.ib(default='text')
d = attr.ib(default=1.0)
c = attr.ib(default={'t': 1})
By default, all combinations of slots and frozen classes will be generated.
If `slots=True` is passed in, only slots classes will be generated, and
if `slots=False` is passed in, no slot classes will be generated. The same
applies to `frozen`.
"""
attrs = draw(list_of_attrs)
frozen_flag = draw(st.booleans()) if frozen is None else frozen
slots_flag = draw(st.booleans()) if slots is None else slots
return make_class('HypClass', dict(zip(_gen_attr_names(), attrs)),
slots=slots_flag, frozen=frozen_flag)
def test_attr_args(self):
"""
attributes_arguments are passed to attributes
"""
C = make_class("C", ["x"], repr=False)
assert repr(C(1)).startswith("<attr._make.C object at 0x")
def test_frozen(self):
"""
Converters circumvent immutability.
"""
C = make_class("C", {"x": attr(convert=lambda v: int(v))}, frozen=True)
C("1")
def test_success(self):
"""
If the validator suceeds, nothing gets raised.
"""
C = make_class("C", {"x": attr(validator=lambda _, __: None)})
validate(C(1))
def _create_hyp_class(attrs):
"""
A helper function for Hypothesis to generate attrs classes.
"""
return make_class("HypClass", dict(zip(gen_attr_names(), attrs)))