blob: 0c90532d9420738093903df3053c701bc533c8a4 [file] [log] [blame]
"""
Tests for `attr._make`.
"""
from __future__ import absolute_import, division, print_function
import inspect
import sys
from operator import attrgetter
import pytest
from hypothesis import given
from hypothesis.strategies import booleans, integers, lists, sampled_from, text
import attr
from attr import _config
from attr._compat import PY2
from attr._make import (
Attribute,
Factory,
_AndValidator,
_Attributes,
_ClassBuilder,
_CountingAttr,
_transform_attrs,
and_,
fields,
make_class,
validate,
)
from attr.exceptions import NotAnAttrsClassError, DefaultAlreadySetError
from .utils import (gen_attr_names, list_of_attrs, simple_attr, simple_attrs,
simple_attrs_without_metadata, simple_classes)
attrs_st = simple_attrs.map(lambda c: Attribute.from_counting_attr("name", c))
class TestCountingAttr(object):
"""
Tests for `attr`.
"""
def test_returns_Attr(self):
"""
Returns an instance of _CountingAttr.
"""
a = attr.ib()
assert isinstance(a, _CountingAttr)
def test_validators_lists_to_wrapped_tuples(self):
"""
If a list is passed as validator, it's just converted to a tuple.
"""
def v1(_, __):
pass
def v2(_, __):
pass
a = attr.ib(validator=[v1, v2])
assert _AndValidator((v1, v2,)) == a._validator
def test_validator_decorator_single(self):
"""
If _CountingAttr.validator is used as a decorator and there is no
decorator set, the decorated method is used as the validator.
"""
a = attr.ib()
@a.validator
def v():
pass
assert v == a._validator
@pytest.mark.parametrize("wrap", [
lambda v: v,
lambda v: [v],
lambda v: and_(v)
])
def test_validator_decorator(self, wrap):
"""
If _CountingAttr.validator is used as a decorator and there is already
a decorator set, the decorators are composed using `and_`.
"""
def v(_, __):
pass
a = attr.ib(validator=wrap(v))
@a.validator
def v2(self, _, __):
pass
assert _AndValidator((v, v2,)) == a._validator
def test_default_decorator_already_set(self):
"""
Raise DefaultAlreadySetError if the decorator is used after a default
has been set.
"""
a = attr.ib(default=42)
with pytest.raises(DefaultAlreadySetError):
@a.default
def f(self):
pass
def test_default_decorator_sets(self):
"""
Decorator wraps the method in a Factory with pass_self=True and sets
the default.
"""
a = attr.ib()
@a.default
def f(self):
pass
assert Factory(f, True) == a._default
def make_tc():
class TransformC(object):
z = attr.ib()
y = attr.ib()
x = attr.ib()
a = 42
return TransformC
class TestTransformAttrs(object):
"""
Tests for `_transform_attrs`.
"""
def test_no_modifications(self):
"""
Doesn't attach __attrs_attrs__ to the class anymore.
"""
C = make_tc()
_transform_attrs(C, None, False)
assert None is getattr(C, "__attrs_attrs__", None)
def test_normal(self):
"""
Transforms every `_CountingAttr` and leaves others (a) be.
"""
C = make_tc()
attrs, _, = _transform_attrs(C, None, False)
assert ["z", "y", "x"] == [a.name for a in attrs]
def test_empty(self):
"""
No attributes works as expected.
"""
@attr.s
class C(object):
pass
assert _Attributes(((), [])) == _transform_attrs(C, None, False)
def test_transforms_to_attribute(self):
"""
All `_CountingAttr`s are transformed into `Attribute`s.
"""
C = make_tc()
attrs, super_attrs = _transform_attrs(C, None, False)
assert [] == super_attrs
assert 3 == len(attrs)
assert all(isinstance(a, Attribute) for a in attrs)
def test_conflicting_defaults(self):
"""
Raises `ValueError` if attributes with defaults are followed by
mandatory attributes.
"""
class C(object):
x = attr.ib(default=None)
y = attr.ib()
with pytest.raises(ValueError) as e:
_transform_attrs(C, None, False)
assert (
"No mandatory attributes allowed after an attribute with a "
"default value or factory. Attribute in question: Attribute"
"(name='y', default=NOTHING, validator=None, repr=True, "
"cmp=True, hash=None, init=True, convert=None, "
"metadata=mappingproxy({}), type=None)",
) == e.value.args
def test_these(self):
"""
If these is passed, use it and ignore body and super classes.
"""
class Base(object):
z = attr.ib()
class C(Base):
y = attr.ib()
attrs, super_attrs = _transform_attrs(C, {"x": attr.ib()}, False)
assert [] == super_attrs
assert (
simple_attr("x"),
) == attrs
class TestAttributes(object):
"""
Tests for the `attrs`/`attr.s` class decorator.
"""
@pytest.mark.skipif(not PY2, reason="No old-style classes in Py3")
def test_catches_old_style(self):
"""
Raises TypeError on old-style classes.
"""
with pytest.raises(TypeError) as e:
@attr.s
class C:
pass
assert ("attrs only works with new-style classes.",) == e.value.args
def test_sets_attrs(self):
"""
Sets the `__attrs_attrs__` class attribute with a list of `Attribute`s.
"""
@attr.s
class C(object):
x = attr.ib()
assert "x" == C.__attrs_attrs__[0].name
assert all(isinstance(a, Attribute) for a in C.__attrs_attrs__)
def test_empty(self):
"""
No attributes, no problems.
"""
@attr.s
class C3(object):
pass
assert "C3()" == repr(C3())
assert C3() == C3()
@given(attr=attrs_st, attr_name=sampled_from(Attribute.__slots__))
def test_immutable(self, attr, attr_name):
"""
Attribute instances are immutable.
"""
with pytest.raises(AttributeError):
setattr(attr, attr_name, 1)
@pytest.mark.parametrize("method_name", [
"__repr__",
"__eq__",
"__hash__",
"__init__",
])
def test_adds_all_by_default(self, method_name):
"""
If no further arguments are supplied, all add_XXX functions except
add_hash are applied. __hash__ is set to None.
"""
# Set the method name to a sentinel and check whether it has been
# overwritten afterwards.
sentinel = object()
class C(object):
x = attr.ib()
setattr(C, method_name, sentinel)
C = attr.s(C)
meth = getattr(C, method_name)
assert sentinel != meth
if method_name == "__hash__":
assert meth is None
@pytest.mark.parametrize("arg_name, method_name", [
("repr", "__repr__"),
("cmp", "__eq__"),
("hash", "__hash__"),
("init", "__init__"),
])
def test_respects_add_arguments(self, arg_name, method_name):
"""
If a certain `add_XXX` is `False`, `__XXX__` is not added to the class.
"""
# Set the method name to a sentinel and check whether it has been
# overwritten afterwards.
sentinel = object()
am_args = {
"repr": True,
"cmp": True,
"hash": True,
"init": True
}
am_args[arg_name] = False
class C(object):
x = attr.ib()
setattr(C, method_name, sentinel)
C = attr.s(**am_args)(C)
assert sentinel == getattr(C, method_name)
@pytest.mark.skipif(PY2, reason="__qualname__ is PY3-only.")
@given(slots_outer=booleans(), slots_inner=booleans())
def test_repr_qualname(self, slots_outer, slots_inner):
"""
On Python 3, the name in repr is the __qualname__.
"""
@attr.s(slots=slots_outer)
class C(object):
@attr.s(slots=slots_inner)
class D(object):
pass
assert "C.D()" == repr(C.D())
assert "GC.D()" == repr(GC.D())
@given(slots_outer=booleans(), slots_inner=booleans())
def test_repr_fake_qualname(self, slots_outer, slots_inner):
"""
Setting repr_ns overrides a potentially guessed namespace.
"""
@attr.s(slots=slots_outer)
class C(object):
@attr.s(repr_ns="C", slots=slots_inner)
class D(object):
pass
assert "C.D()" == repr(C.D())
@pytest.mark.skipif(PY2, reason="__qualname__ is PY3-only.")
@given(slots_outer=booleans(), slots_inner=booleans())
def test_name_not_overridden(self, slots_outer, slots_inner):
"""
On Python 3, __name__ is different from __qualname__.
"""
@attr.s(slots=slots_outer)
class C(object):
@attr.s(slots=slots_inner)
class D(object):
pass
assert C.D.__name__ == "D"
assert C.D.__qualname__ == C.__qualname__ + ".D"
@given(with_validation=booleans())
def test_post_init(self, with_validation, monkeypatch):
"""
Verify that __attrs_post_init__ gets called if defined.
"""
monkeypatch.setattr(_config, "_run_validators", with_validation)
@attr.s
class C(object):
x = attr.ib()
y = attr.ib()
def __attrs_post_init__(self2):
self2.z = self2.x + self2.y
c = C(x=10, y=20)
assert 30 == getattr(c, 'z', None)
def test_types(self):
"""
Sets the `Attribute.type` attr from type argument.
"""
@attr.s
class C(object):
x = attr.ib(type=int)
y = attr.ib(type=str)
z = attr.ib()
assert int is fields(C).x.type
assert str is fields(C).y.type
assert None is fields(C).z.type
@pytest.mark.parametrize("slots", [True, False])
def test_clean_class(self, slots):
"""
Attribute definitions do not appear on the class body after @attr.s.
"""
@attr.s(slots=slots)
class C(object):
x = attr.ib()
x = getattr(C, "x", None)
assert not isinstance(x, _CountingAttr)
@attr.s
class GC(object):
@attr.s
class D(object):
pass
class TestMakeClass(object):
"""
Tests for `make_class`.
"""
@pytest.mark.parametrize("ls", [
list,
tuple
])
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.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_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_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_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)
@pytest.mark.parametrize("slots", [True, False])
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_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__)
class TestFields(object):
"""
Tests for `fields`.
"""
def test_instance(self, C):
"""
Raises `TypeError` on non-classes.
"""
with pytest.raises(TypeError) as e:
fields(C(1, 2))
assert "Passed object must be a class." == e.value.args[0]
def test_handler_non_attrs_class(self, C):
"""
Raises `ValueError` if passed a non-``attrs`` instance.
"""
with pytest.raises(NotAnAttrsClassError) as e:
fields(object)
assert (
"{o!r} is not an attrs-decorated class.".format(o=object)
) == e.value.args[0]
@given(simple_classes())
def test_fields(self, C):
"""
Returns a list of `Attribute`a.
"""
assert all(isinstance(a, Attribute) for a in fields(C))
@given(simple_classes())
def test_fields_properties(self, C):
"""
Fields returns a tuple with properties.
"""
for attribute in fields(C):
assert getattr(fields(C), attribute.name) is attribute
class TestConvert(object):
"""
Tests for attribute conversion.
"""
def test_convert(self):
"""
Return value of convert is used as the attribute's value.
"""
C = make_class("C", {
"x": attr.ib(convert=lambda v: v + 1),
"y": attr.ib(),
})
c = C(1, 2)
assert c.x == 2
assert c.y == 2
@given(integers(), booleans())
def test_convert_property(self, val, init):
"""
Property tests for attributes with convert.
"""
C = make_class("C", {
"y": attr.ib(),
"x": attr.ib(init=init, default=val, convert=lambda v: v + 1),
})
c = C(2)
assert c.x == val + 1
assert c.y == 2
@given(integers(), booleans())
def test_convert_factory_property(self, val, init):
"""
Property tests for attributes with convert, and a factory default.
"""
C = make_class("C", {
"y": attr.ib(),
"x": attr.ib(
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_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_factory_hashable(self):
"""
Factory is hashable.
"""
assert hash(Factory(None, False)) == hash(Factory(None, False))
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, convert=lambda v: 1 / 0),
"y": attr.ib(),
})
with pytest.raises(ZeroDivisionError):
C(1, 2)
def test_frozen(self):
"""
Converters circumvent immutability.
"""
C = make_class("C", {
"x": attr.ib(convert=lambda v: int(v)),
}, frozen=True)
C("1")
class TestValidate(object):
"""
Tests for `validate`.
"""
def test_success(self):
"""
If the validator succeeds, nothing gets raised.
"""
C = make_class("C", {
"x": attr.ib(validator=lambda *a: None),
"y": attr.ib()
})
validate(C(1, 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_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.ib(validator=raiser)})
c = C(1)
validate(c)
assert 1 == c.x
_config._run_validators = True
with pytest.raises(Exception):
validate(c)
with pytest.raises(Exception) as e:
C(1)
assert (obj,) == e.value.args
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_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__)
# Hypothesis seems to cache values, so the lists of attributes come out
# unsorted.
sorted_lists_of_attrs = list_of_attrs.map(
lambda l: sorted(l, key=attrgetter("counter")))
class TestMetadata(object):
"""
Tests for metadata handling.
"""
@given(sorted_lists_of_attrs)
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))
@given(simple_classes(), text())
def test_metadata_immutability(self, C, string):
"""
The metadata dict should be best-effort immutable.
"""
for a in fields(C):
with pytest.raises(TypeError):
a.metadata[string] = string
with pytest.raises(AttributeError):
a.metadata.update({string: string})
with pytest.raises(AttributeError):
a.metadata.clear()
with pytest.raises(AttributeError):
a.metadata.setdefault(string, string)
for k in a.metadata:
# For some reason, Python 3's MappingProxyType throws an
# IndexError for deletes on a large integer key.
with pytest.raises((TypeError, IndexError)):
del a.metadata[k]
with pytest.raises(AttributeError):
a.metadata.pop(k)
with pytest.raises(AttributeError):
a.metadata.popitem()
@given(lists(simple_attrs_without_metadata, min_size=2, max_size=5))
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
class TestClassBuilder(object):
"""
Tests for `_ClassBuilder`.
"""
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_repr(self):
"""
repr of builder itself makes sense.
"""
class C(object):
pass
b = _ClassBuilder(C, None, True, True, False)
assert "<_ClassBuilder(cls=C)>" == repr(b)
def test_returns_self(self):
"""
All methods return the builder for chaining.
"""
class C(object):
x = attr.ib()
b = _ClassBuilder(C, None, True, True, False)
cls = b.add_cmp().add_hash().add_init().add_repr("ns").add_str() \
.build_class()
assert "ns.C(x=1)" == repr(cls(1))