blob: d4d8640cda428c7413de65bf90cd706b7b051414 [file] [log] [blame]
# SPDX-License-Identifier: MIT
"""
Tests for `attr._make`.
"""
import copy
import functools
import gc
import inspect
import itertools
import sys
from operator import attrgetter
import pytest
from hypothesis import assume, given
from hypothesis.strategies import booleans, integers, lists, sampled_from, text
import attr
from attr import _config
from attr._compat import PY310, ordered_dict
from attr._make import (
Attribute,
Factory,
_AndValidator,
_Attributes,
_ClassBuilder,
_CountingAttr,
_determine_attrib_eq_order,
_determine_attrs_eq_order,
_determine_whether_to_implement,
_transform_attrs,
and_,
fields,
fields_dict,
make_class,
validate,
)
from attr.exceptions import DefaultAlreadySetError, NotAnAttrsClassError
from .strategies import (
gen_attr_names,
list_of_attrs,
optional_bool,
simple_attrs,
simple_attrs_with_metadata,
simple_attrs_without_metadata,
simple_classes,
)
from .utils import simple_attr
attrs_st = simple_attrs.map(lambda c: Attribute.from_counting_attr("name", c))
class TestCountingAttr:
"""
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:
z = attr.ib()
y = attr.ib()
x = attr.ib()
a = 42
return TransformC
class TestTransformAttrs:
"""
Tests for `_transform_attrs`.
"""
def test_no_modifications(self):
"""
Does not attach __attrs_attrs__ to the class.
"""
C = make_tc()
_transform_attrs(C, None, False, False, True, None)
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, False, True, None)
assert ["z", "y", "x"] == [a.name for a in attrs]
def test_empty(self):
"""
No attributes works as expected.
"""
@attr.s
class C:
pass
assert _Attributes(((), [], {})) == _transform_attrs(
C, None, False, False, True, None
)
def test_transforms_to_attribute(self):
"""
All `_CountingAttr`s are transformed into `Attribute`s.
"""
C = make_tc()
attrs, base_attrs, _ = _transform_attrs(
C, None, False, False, True, None
)
assert [] == base_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:
x = attr.ib(default=None)
y = attr.ib()
with pytest.raises(ValueError) as e:
_transform_attrs(C, None, False, False, True, None)
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, "
"eq=True, eq_key=None, order=True, order_key=None, "
"hash=None, init=True, "
"metadata=mappingproxy({}), type=None, converter=None, "
"kw_only=False, inherited=False, on_setattr=None)",
) == e.value.args
def test_kw_only(self):
"""
Converts all attributes, including base class' attributes, if `kw_only`
is provided. Therefore, `kw_only` allows attributes with defaults to
precede mandatory attributes.
Updates in the subclass *don't* affect the base class attributes.
"""
@attr.s
class B:
b = attr.ib()
for b_a in B.__attrs_attrs__:
assert b_a.kw_only is False
class C(B):
x = attr.ib(default=None)
y = attr.ib()
attrs, base_attrs, _ = _transform_attrs(
C, None, False, True, True, None
)
assert len(attrs) == 3
assert len(base_attrs) == 1
for a in attrs:
assert a.kw_only is True
for b_a in B.__attrs_attrs__:
assert b_a.kw_only is False
def test_these(self):
"""
If these is passed, use it and ignore body and base classes.
"""
class Base:
z = attr.ib()
class C(Base):
y = attr.ib()
attrs, base_attrs, _ = _transform_attrs(
C, {"x": attr.ib()}, False, False, True, None
)
assert [] == base_attrs
assert (simple_attr("x"),) == attrs
def test_these_leave_body(self):
"""
If these is passed, no attributes are removed from the body.
"""
@attr.s(init=False, these={"x": attr.ib()})
class C:
x = 5
assert 5 == C().x
assert "C(x=5)" == repr(C())
def test_these_ordered(self):
"""
If these is passed ordered attrs, their order respect instead of the
counter.
"""
b = attr.ib(default=2)
a = attr.ib(default=1)
@attr.s(these=ordered_dict([("a", a), ("b", b)]))
class C:
pass
assert "C(a=1, b=2)" == repr(C())
def test_multiple_inheritance_old(self):
"""
Old multiple inheritance attribute collection behavior is retained.
See #285
"""
@attr.s
class A:
a1 = attr.ib(default="a1")
a2 = attr.ib(default="a2")
@attr.s
class B(A):
b1 = attr.ib(default="b1")
b2 = attr.ib(default="b2")
@attr.s
class C(B, A):
c1 = attr.ib(default="c1")
c2 = attr.ib(default="c2")
@attr.s
class D(A):
d1 = attr.ib(default="d1")
d2 = attr.ib(default="d2")
@attr.s
class E(C, D):
e1 = attr.ib(default="e1")
e2 = attr.ib(default="e2")
assert (
"E(a1='a1', a2='a2', b1='b1', b2='b2', c1='c1', c2='c2', d1='d1', "
"d2='d2', e1='e1', e2='e2')"
) == repr(E())
def test_overwrite_proper_mro(self):
"""
The proper MRO path works single overwrites too.
"""
@attr.s(collect_by_mro=True)
class C:
x = attr.ib(default=1)
@attr.s(collect_by_mro=True)
class D(C):
x = attr.ib(default=2)
assert "D(x=2)" == repr(D())
def test_multiple_inheritance_proper_mro(self):
"""
Attributes are collected according to the MRO.
See #428
"""
@attr.s
class A:
a1 = attr.ib(default="a1")
a2 = attr.ib(default="a2")
@attr.s
class B(A):
b1 = attr.ib(default="b1")
b2 = attr.ib(default="b2")
@attr.s
class C(B, A):
c1 = attr.ib(default="c1")
c2 = attr.ib(default="c2")
@attr.s
class D(A):
d1 = attr.ib(default="d1")
d2 = attr.ib(default="d2")
@attr.s(collect_by_mro=True)
class E(C, D):
e1 = attr.ib(default="e1")
e2 = attr.ib(default="e2")
assert (
"E(a1='a1', a2='a2', d1='d1', d2='d2', b1='b1', b2='b2', c1='c1', "
"c2='c2', e1='e1', e2='e2')"
) == repr(E())
def test_mro(self):
"""
Attributes and methods are looked up the same way.
See #428
"""
@attr.s(collect_by_mro=True)
class A:
x = attr.ib(10)
def xx(self):
return 10
@attr.s(collect_by_mro=True)
class B(A):
y = attr.ib(20)
@attr.s(collect_by_mro=True)
class C(A):
x = attr.ib(50)
def xx(self):
return 50
@attr.s(collect_by_mro=True)
class D(B, C):
pass
d = D()
assert d.x == d.xx()
def test_inherited(self):
"""
Inherited Attributes have `.inherited` True, otherwise False.
"""
@attr.s
class A:
a = attr.ib()
@attr.s
class B(A):
b = attr.ib()
@attr.s
class C(B):
a = attr.ib()
c = attr.ib()
f = attr.fields
assert False is f(A).a.inherited
assert True is f(B).a.inherited
assert False is f(B).b.inherited
assert False is f(C).a.inherited
assert True is f(C).b.inherited
assert False is f(C).c.inherited
class TestAttributes:
"""
Tests for the `attrs`/`attr.s` class decorator.
"""
def test_sets_attrs(self):
"""
Sets the `__attrs_attrs__` class attribute with a list of `Attribute`s.
"""
@attr.s
class C:
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:
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:
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__"),
("eq", "__eq__"),
("order", "__le__"),
("hash", "__hash__"),
("init", "__init__"),
],
)
def test_respects_add_arguments(self, arg_name, method_name):
"""
If a certain `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,
"eq": True,
"order": True,
"hash": True,
"init": True,
}
am_args[arg_name] = False
if arg_name == "eq":
am_args["order"] = False
class C:
x = attr.ib()
setattr(C, method_name, sentinel)
C = attr.s(**am_args)(C)
assert sentinel == getattr(C, method_name)
@pytest.mark.parametrize("init", [True, False])
def test_respects_init_attrs_init(self, init):
"""
If init=False, adds __attrs_init__ to the class.
Otherwise, it does not.
"""
class C:
x = attr.ib()
C = attr.s(init=init)(C)
assert hasattr(C, "__attrs_init__") != init
@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:
@attr.s(slots=slots_inner)
class D:
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:
@attr.s(repr_ns="C", slots=slots_inner)
class D:
pass
assert "C.D()" == repr(C.D())
@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:
@attr.s(slots=slots_inner)
class D:
pass
assert C.D.__name__ == "D"
assert C.D.__qualname__ == C.__qualname__ + ".D"
@pytest.mark.parametrize("with_validation", [True, False])
def test_pre_init(self, with_validation, monkeypatch):
"""
Verify that __attrs_pre_init__ gets called if defined.
"""
monkeypatch.setattr(_config, "_run_validators", with_validation)
@attr.s
class C:
def __attrs_pre_init__(self2):
self2.z = 30
c = C()
assert 30 == getattr(c, "z", None)
@pytest.mark.parametrize("with_validation", [True, False])
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:
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)
@pytest.mark.parametrize("with_validation", [True, False])
def test_pre_post_init_order(self, with_validation, monkeypatch):
"""
Verify that __attrs_post_init__ gets called if defined.
"""
monkeypatch.setattr(_config, "_run_validators", with_validation)
@attr.s
class C:
x = attr.ib()
def __attrs_pre_init__(self2):
self2.z = 30
def __attrs_post_init__(self2):
self2.z += self2.x
c = C(x=10)
assert 40 == getattr(c, "z", None)
def test_types(self):
"""
Sets the `Attribute.type` attr from type argument.
"""
@attr.s
class C:
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:
x = attr.ib()
x = getattr(C, "x", None)
assert not isinstance(x, _CountingAttr)
def test_factory_sugar(self):
"""
Passing factory=f is syntactic sugar for passing default=Factory(f).
"""
@attr.s
class C:
x = attr.ib(factory=list)
assert Factory(list) == attr.fields(C).x.default
def test_sugar_factory_mutex(self):
"""
Passing both default and factory raises ValueError.
"""
with pytest.raises(ValueError, match="mutually exclusive"):
@attr.s
class C:
x = attr.ib(factory=list, default=Factory(list))
def test_sugar_callable(self):
"""
Factory has to be a callable to prevent people from passing Factory
into it.
"""
with pytest.raises(ValueError, match="must be a callable"):
@attr.s
class C:
x = attr.ib(factory=Factory(list))
def test_inherited_does_not_affect_hashing_and_equality(self):
"""
Whether or not an Attribute has been inherited doesn't affect how it's
hashed and compared.
"""
@attr.s
class BaseClass:
x = attr.ib()
@attr.s
class SubClass(BaseClass):
pass
ba = attr.fields(BaseClass)[0]
sa = attr.fields(SubClass)[0]
assert ba == sa
assert hash(ba) == hash(sa)
class TestKeywordOnlyAttributes:
"""
Tests for keyword-only attributes.
"""
def test_adds_keyword_only_arguments(self):
"""
Attributes can be added as keyword-only.
"""
@attr.s
class C:
a = attr.ib()
b = attr.ib(default=2, kw_only=True)
c = attr.ib(kw_only=True)
d = attr.ib(default=attr.Factory(lambda: 4), kw_only=True)
c = C(1, c=3)
assert c.a == 1
assert c.b == 2
assert c.c == 3
assert c.d == 4
def test_ignores_kw_only_when_init_is_false(self):
"""
Specifying ``kw_only=True`` when ``init=False`` is essentially a no-op.
"""
@attr.s
class C:
x = attr.ib(init=False, default=0, kw_only=True)
y = attr.ib()
c = C(1)
assert c.x == 0
assert c.y == 1
def test_keyword_only_attributes_presence(self):
"""
Raises `TypeError` when keyword-only arguments are
not specified.
"""
@attr.s
class C:
x = attr.ib(kw_only=True)
with pytest.raises(TypeError) as e:
C()
assert (
"missing 1 required keyword-only argument: 'x'"
) in e.value.args[0]
def test_keyword_only_attributes_unexpected(self):
"""
Raises `TypeError` when unexpected keyword argument passed.
"""
@attr.s
class C:
x = attr.ib(kw_only=True)
with pytest.raises(TypeError) as e:
C(x=5, y=10)
assert "got an unexpected keyword argument 'y'" in e.value.args[0]
def test_keyword_only_attributes_can_come_in_any_order(self):
"""
Mandatory vs non-mandatory attr order only matters when they are part
of the __init__ signature and when they aren't kw_only (which are
moved to the end and can be mandatory or non-mandatory in any order,
as they will be specified as keyword args anyway).
"""
@attr.s
class C:
a = attr.ib(kw_only=True)
b = attr.ib(kw_only=True, default="b")
c = attr.ib(kw_only=True)
d = attr.ib()
e = attr.ib(default="e")
f = attr.ib(kw_only=True)
g = attr.ib(kw_only=True, default="g")
h = attr.ib(kw_only=True)
i = attr.ib(init=False)
c = C("d", a="a", c="c", f="f", h="h")
assert c.a == "a"
assert c.b == "b"
assert c.c == "c"
assert c.d == "d"
assert c.e == "e"
assert c.f == "f"
assert c.g == "g"
assert c.h == "h"
def test_keyword_only_attributes_allow_subclassing(self):
"""
Subclass can define keyword-only attributed without defaults,
when the base class has attributes with defaults.
"""
@attr.s
class Base:
x = attr.ib(default=0)
@attr.s
class C(Base):
y = attr.ib(kw_only=True)
c = C(y=1)
assert c.x == 0
assert c.y == 1
def test_keyword_only_class_level(self):
"""
`kw_only` can be provided at the attr.s level, converting all
attributes to `kw_only.`
"""
@attr.s(kw_only=True)
class C:
x = attr.ib()
y = attr.ib(kw_only=True)
with pytest.raises(TypeError):
C(0, y=1)
c = C(x=0, y=1)
assert c.x == 0
assert c.y == 1
def test_keyword_only_class_level_subclassing(self):
"""
Subclass `kw_only` propagates to attrs inherited from the base,
allowing non-default following default.
"""
@attr.s
class Base:
x = attr.ib(default=0)
@attr.s(kw_only=True)
class C(Base):
y = attr.ib()
with pytest.raises(TypeError):
C(1)
c = C(x=0, y=1)
assert c.x == 0
assert c.y == 1
def test_init_false_attribute_after_keyword_attribute(self):
"""
A positional attribute cannot follow a `kw_only` attribute,
but an `init=False` attribute can because it won't appear
in `__init__`
"""
@attr.s
class KwArgBeforeInitFalse:
kwarg = attr.ib(kw_only=True)
non_init_function_default = attr.ib(init=False)
non_init_keyword_default = attr.ib(
init=False, default="default-by-keyword"
)
@non_init_function_default.default
def _init_to_init(self):
return self.kwarg + "b"
c = KwArgBeforeInitFalse(kwarg="a")
assert c.kwarg == "a"
assert c.non_init_function_default == "ab"
assert c.non_init_keyword_default == "default-by-keyword"
def test_init_false_attribute_after_keyword_attribute_with_inheritance(
self,
):
"""
A positional attribute cannot follow a `kw_only` attribute,
but an `init=False` attribute can because it won't appear
in `__init__`. This test checks that we allow this
even when the `kw_only` attribute appears in a parent class
"""
@attr.s
class KwArgBeforeInitFalseParent:
kwarg = attr.ib(kw_only=True)
@attr.s
class KwArgBeforeInitFalseChild(KwArgBeforeInitFalseParent):
non_init_function_default = attr.ib(init=False)
non_init_keyword_default = attr.ib(
init=False, default="default-by-keyword"
)
@non_init_function_default.default
def _init_to_init(self):
return self.kwarg + "b"
c = KwArgBeforeInitFalseChild(kwarg="a")
assert c.kwarg == "a"
assert c.non_init_function_default == "ab"
assert c.non_init_keyword_default == "default-by-keyword"
@attr.s
class GC:
@attr.s
class D:
pass
class TestMakeClass:
"""
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:
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:
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:
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__)
def test_make_class_ordered(self):
"""
If `make_class()` is passed ordered attrs, their order is respected
instead of the counter.
"""
b = attr.ib(default=2)
a = attr.ib(default=1)
C = attr.make_class("C", ordered_dict([("a", a), ("b", b)]))
assert "C(a=1, b=2)" == repr(C())
def test_generic_dynamic_class(self):
"""
make_class can create generic dynamic classes.
https://github.com/python-attrs/attrs/issues/756
https://bugs.python.org/issue33188
"""
from types import new_class
from typing import Generic, TypeVar
MyTypeVar = TypeVar("MyTypeVar")
MyParent = new_class("MyParent", (Generic[MyTypeVar],), {})
attr.make_class("test", {"id": attr.ib(type=str)}, (MyParent[int],))
class TestFields:
"""
Tests for `fields`.
"""
@given(simple_classes())
def test_instance(self, C):
"""
Raises `TypeError` on non-classes.
"""
with pytest.raises(TypeError) as e:
fields(C())
assert "Passed object must be a class." == e.value.args[0]
def test_handler_non_attrs_class(self):
"""
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 TestFieldsDict:
"""
Tests for `fields_dict`.
"""
@given(simple_classes())
def test_instance(self, C):
"""
Raises `TypeError` on non-classes.
"""
with pytest.raises(TypeError) as e:
fields_dict(C())
assert "Passed object must be a class." == e.value.args[0]
def test_handler_non_attrs_class(self):
"""
Raises `ValueError` if passed a non-``attrs`` instance.
"""
with pytest.raises(NotAnAttrsClassError) as e:
fields_dict(object)
assert (
"{o!r} is not an attrs-decorated class.".format(o=object)
) == e.value.args[0]
@given(simple_classes())
def test_fields_dict(self, C):
"""
Returns an ordered dict of ``{attribute_name: Attribute}``.
"""
d = fields_dict(C)
assert isinstance(d, ordered_dict)
assert list(fields(C)) == list(d.values())
assert [a.name for a in fields(C)] == [field_name for field_name in d]
class TestConverter:
"""
Tests for attribute conversion.
"""
def test_convert(self):
"""
Return value of converter is used as the attribute's value.
"""
C = make_class(
"C", {"x": attr.ib(converter=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 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
@given(integers(), booleans())
def test_converter_factory_property(self, val, init):
"""
Property tests for attributes with converter, 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_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, converter=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(converter=lambda v: int(v))}, frozen=True
)
C("1")
class TestValidate:
"""
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:
"""
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
@given(lists(simple_attrs_without_metadata, min_size=2, max_size=5))
def test_empty_countingattr_metadata_independent(self, list_of_attrs):
"""
All empty metadata attributes are independent before ``@attr.s``.
"""
for x, y in itertools.combinations(list_of_attrs, 2):
assert x.metadata is not y.metadata
@given(lists(simple_attrs_with_metadata(), min_size=2, max_size=5))
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_metadata(self):
"""
If metadata that is not None is passed, it is used.
This is necessary for coverage because the previous test is
hypothesis-based.
"""
md = {}
a = attr.ib(metadata=md)
assert md is a.metadata
class TestClassBuilder:
"""
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:
pass
b = _ClassBuilder(
C,
None,
True,
True,
False,
False,
False,
False,
False,
False,
True,
None,
False,
None,
)
assert "<_ClassBuilder(cls=C)>" == repr(b)
def test_returns_self(self):
"""
All methods return the builder for chaining.
"""
class C:
x = attr.ib()
b = _ClassBuilder(
C,
None,
True,
True,
False,
False,
False,
False,
False,
False,
True,
None,
False,
None,
)
cls = (
b.add_eq()
.add_order()
.add_hash()
.add_init()
.add_attrs_init()
.add_repr("ns")
.add_str()
.build_class()
)
assert "ns.C(x=1)" == repr(cls(1))
@pytest.mark.parametrize(
"meth_name",
[
"__init__",
"__hash__",
"__repr__",
"__str__",
"__eq__",
"__ne__",
"__lt__",
"__le__",
"__gt__",
"__ge__",
],
)
def test_attaches_meta_dunders(self, meth_name):
"""
Generated methods have correct __module__, __name__, and __qualname__
attributes.
"""
@attr.s(hash=True, str=True)
class C:
def organic(self):
pass
@attr.s(hash=True, str=True)
class D:
pass
meth_C = getattr(C, meth_name)
meth_D = getattr(D, meth_name)
assert meth_name == meth_C.__name__ == meth_D.__name__
assert C.organic.__module__ == meth_C.__module__ == meth_D.__module__
# This is assertion that would fail if a single __ne__ instance
# was reused across multiple _make_eq calls.
organic_prefix = C.organic.__qualname__.rsplit(".", 1)[0]
assert organic_prefix + "." + meth_name == meth_C.__qualname__
def test_handles_missing_meta_on_class(self):
"""
If the class hasn't a __module__ or __qualname__, the method hasn't
either.
"""
class C:
pass
b = _ClassBuilder(
C,
these=None,
slots=False,
frozen=False,
weakref_slot=True,
getstate_setstate=False,
auto_attribs=False,
is_exc=False,
kw_only=False,
cache_hash=False,
collect_by_mro=True,
on_setattr=None,
has_custom_setattr=False,
field_transformer=None,
)
b._cls = {} # no __module__; no __qualname__
def fake_meth(self):
pass
fake_meth.__module__ = "42"
fake_meth.__qualname__ = "23"
rv = b._add_method_dunders(fake_meth)
assert "42" == rv.__module__ == fake_meth.__module__
assert "23" == rv.__qualname__ == fake_meth.__qualname__
def test_weakref_setstate(self):
"""
__weakref__ is not set on in setstate because it's not writable in
slotted classes.
"""
@attr.s(slots=True)
class C:
__weakref__ = attr.ib(
init=False, hash=False, repr=False, eq=False, order=False
)
assert C() == copy.deepcopy(C())
def test_no_references_to_original(self):
"""
When subclassing a slotted class, there are no stray references to the
original class.
"""
@attr.s(slots=True)
class C:
pass
@attr.s(slots=True)
class C2(C):
pass
# The original C2 is in a reference cycle, so force a collect:
gc.collect()
assert [C2] == C.__subclasses__()
def _get_copy_kwargs(include_slots=True):
"""
Generate a list of compatible attr.s arguments for the `copy` tests.
"""
options = ["frozen", "hash", "cache_hash"]
if include_slots:
options.extend(["slots", "weakref_slot"])
out_kwargs = []
for args in itertools.product([True, False], repeat=len(options)):
kwargs = dict(zip(options, args))
kwargs["hash"] = kwargs["hash"] or None
if kwargs["cache_hash"] and not (
kwargs["frozen"] or kwargs["hash"]
):
continue
out_kwargs.append(kwargs)
return out_kwargs
@pytest.mark.parametrize("kwargs", _get_copy_kwargs())
def test_copy(self, kwargs):
"""
Ensure that an attrs class can be copied successfully.
"""
@attr.s(eq=True, **kwargs)
class C:
x = attr.ib()
a = C(1)
b = copy.deepcopy(a)
assert a == b
@pytest.mark.parametrize("kwargs", _get_copy_kwargs(include_slots=False))
def test_copy_custom_setstate(self, kwargs):
"""
Ensure that non-slots classes respect a custom __setstate__.
"""
@attr.s(eq=True, **kwargs)
class C:
x = attr.ib()
def __getstate__(self):
return self.__dict__
def __setstate__(self, state):
state["x"] *= 5
self.__dict__.update(state)
expected = C(25)
actual = copy.copy(C(5))
assert actual == expected
class TestMakeOrder:
"""
Tests for _make_order().
"""
def test_subclasses_cannot_be_compared(self):
"""
Calling comparison methods on subclasses raises a TypeError.
We use the actual operation so we get an error raised on Python 3.
"""
@attr.s
class A:
a = attr.ib()
@attr.s
class B(A):
pass
a = A(42)
b = B(42)
assert a <= a
assert a >= a
assert not a < a
assert not a > a
assert (
NotImplemented
== a.__lt__(b)
== a.__le__(b)
== a.__gt__(b)
== a.__ge__(b)
)
with pytest.raises(TypeError):
a <= b
with pytest.raises(TypeError):
a >= b
with pytest.raises(TypeError):
a < b
with pytest.raises(TypeError):
a > b
class TestDetermineAttrsEqOrder:
def test_default(self):
"""
If all are set to None, set both eq and order to the passed default.
"""
assert (42, 42) == _determine_attrs_eq_order(None, None, None, 42)
@pytest.mark.parametrize("eq", [True, False])
def test_order_mirrors_eq_by_default(self, eq):
"""
If order is None, it mirrors eq.
"""
assert (eq, eq) == _determine_attrs_eq_order(None, eq, None, True)
def test_order_without_eq(self):
"""
eq=False, order=True raises a meaningful ValueError.
"""
with pytest.raises(
ValueError, match="`order` can only be True if `eq` is True too."
):
_determine_attrs_eq_order(None, False, True, True)
@given(cmp=booleans(), eq=optional_bool, order=optional_bool)
def test_mix(self, cmp, eq, order):
"""
If cmp is not None, eq and order must be None and vice versa.
"""
assume(eq is not None or order is not None)
with pytest.raises(
ValueError, match="Don't mix `cmp` with `eq' and `order`."
):
_determine_attrs_eq_order(cmp, eq, order, True)
class TestDetermineAttribEqOrder:
def test_default(self):
"""
If all are set to None, set both eq and order to the passed default.
"""
assert (42, None, 42, None) == _determine_attrib_eq_order(
None, None, None, 42
)
def test_eq_callable_order_boolean(self):
"""
eq=callable or order=callable need to transformed into eq/eq_key
or order/order_key.
"""
assert (True, str.lower, False, None) == _determine_attrib_eq_order(
None, str.lower, False, True
)
def test_eq_callable_order_callable(self):
"""
eq=callable or order=callable need to transformed into eq/eq_key
or order/order_key.
"""
assert (True, str.lower, True, abs) == _determine_attrib_eq_order(
None, str.lower, abs, True
)
def test_eq_boolean_order_callable(self):
"""
eq=callable or order=callable need to transformed into eq/eq_key
or order/order_key.
"""
assert (True, None, True, str.lower) == _determine_attrib_eq_order(
None, True, str.lower, True
)
@pytest.mark.parametrize("eq", [True, False])
def test_order_mirrors_eq_by_default(self, eq):
"""
If order is None, it mirrors eq.
"""
assert (eq, None, eq, None) == _determine_attrib_eq_order(
None, eq, None, True
)
def test_order_without_eq(self):
"""
eq=False, order=True raises a meaningful ValueError.
"""
with pytest.raises(
ValueError, match="`order` can only be True if `eq` is True too."
):
_determine_attrib_eq_order(None, False, True, True)
@given(cmp=booleans(), eq=optional_bool, order=optional_bool)
def test_mix(self, cmp, eq, order):
"""
If cmp is not None, eq and order must be None and vice versa.
"""
assume(eq is not None or order is not None)
with pytest.raises(
ValueError, match="Don't mix `cmp` with `eq' and `order`."
):
_determine_attrib_eq_order(cmp, eq, order, True)
class TestDocs:
@pytest.mark.parametrize(
"meth_name",
[
"__init__",
"__repr__",
"__eq__",
"__ne__",
"__lt__",
"__le__",
"__gt__",
"__ge__",
],
)
def test_docs(self, meth_name):
"""
Tests the presence and correctness of the documentation
for the generated methods
"""
@attr.s
class A:
pass
if hasattr(A, "__qualname__"):
method = getattr(A, meth_name)
expected = "Method generated by attrs for class {}.".format(
A.__qualname__
)
assert expected == method.__doc__
class BareC:
pass
class BareSlottedC:
__slots__ = ()
class TestAutoDetect:
@pytest.mark.parametrize("C", (BareC, BareSlottedC))
def test_determine_detects_non_presence_correctly(self, C):
"""
On an empty class, nothing should be detected.
"""
assert True is _determine_whether_to_implement(
C, None, True, ("__init__",)
)
assert True is _determine_whether_to_implement(
C, None, True, ("__repr__",)
)
assert True is _determine_whether_to_implement(
C, None, True, ("__eq__", "__ne__")
)
assert True is _determine_whether_to_implement(
C, None, True, ("__le__", "__lt__", "__ge__", "__gt__")
)
@pytest.mark.parametrize("slots", [True, False])
@pytest.mark.parametrize("frozen", [True, False])
def test_make_all_by_default(self, slots, frozen):
"""
If nothing is there to be detected, imply init=True, repr=True,
hash=None, eq=True, order=True.
"""
@attr.s(auto_detect=True, slots=slots, frozen=frozen)
class C:
x = attr.ib()
i = C(1)
o = object()
assert i.__init__ is not o.__init__
assert i.__repr__ is not o.__repr__
assert i.__eq__ is not o.__eq__
assert i.__ne__ is not o.__ne__
assert i.__le__ is not o.__le__
assert i.__lt__ is not o.__lt__
assert i.__ge__ is not o.__ge__
assert i.__gt__ is not o.__gt__
@pytest.mark.parametrize("slots", [True, False])
@pytest.mark.parametrize("frozen", [True, False])
def test_detect_auto_init(self, slots, frozen):
"""
If auto_detect=True and an __init__ exists, don't write one.
"""
@attr.s(auto_detect=True, slots=slots, frozen=frozen)
class CI:
x = attr.ib()
def __init__(self):
object.__setattr__(self, "x", 42)
assert 42 == CI().x
@pytest.mark.parametrize("slots", [True, False])
@pytest.mark.parametrize("frozen", [True, False])
def test_detect_auto_repr(self, slots, frozen):
"""
If auto_detect=True and an __repr__ exists, don't write one.
"""
@attr.s(auto_detect=True, slots=slots, frozen=frozen)
class C:
x = attr.ib()
def __repr__(self):
return "hi"
assert "hi" == repr(C(42))
@pytest.mark.parametrize("slots", [True, False])
@pytest.mark.parametrize("frozen", [True, False])
def test_hash_uses_eq(self, slots, frozen):
"""
If eq is passed in, then __hash__ should use the eq callable
to generate the hash code.
"""
@attr.s(slots=slots, frozen=frozen, hash=True)
class C:
x = attr.ib(eq=str)
@attr.s(slots=slots, frozen=frozen, hash=True)
class D:
x = attr.ib()
# These hashes should be the same because 1 is turned into
# string before hashing.
assert hash(C("1")) == hash(C(1))
assert hash(D("1")) != hash(D(1))
@pytest.mark.parametrize("slots", [True, False])
@pytest.mark.parametrize("frozen", [True, False])
def test_detect_auto_hash(self, slots, frozen):
"""
If auto_detect=True and an __hash__ exists, don't write one.
"""
@attr.s(auto_detect=True, slots=slots, frozen=frozen)
class C:
x = attr.ib()
def __hash__(self):
return 0xC0FFEE
assert 0xC0FFEE == hash(C(42))
@pytest.mark.parametrize("slots", [True, False])
@pytest.mark.parametrize("frozen", [True, False])
def test_detect_auto_eq(self, slots, frozen):
"""
If auto_detect=True and an __eq__ or an __ne__, exist, don't write one.
"""
@attr.s(auto_detect=True, slots=slots, frozen=frozen)
class C:
x = attr.ib()
def __eq__(self, o):
raise ValueError("worked")
with pytest.raises(ValueError, match="worked"):
C(1) == C(1)
@attr.s(auto_detect=True, slots=slots, frozen=frozen)
class D:
x = attr.ib()
def __ne__(self, o):
raise ValueError("worked")
with pytest.raises(ValueError, match="worked"):
D(1) != D(1)
@pytest.mark.parametrize("slots", [True, False])
@pytest.mark.parametrize("frozen", [True, False])
def test_detect_auto_order(self, slots, frozen):
"""
If auto_detect=True and an __ge__, __gt__, __le__, or and __lt__ exist,
don't write one.
It's surprisingly difficult to test this programmatically, so we do it
by hand.
"""
def assert_not_set(cls, ex, meth_name):
__tracebackhide__ = True
a = getattr(cls, meth_name)
if meth_name == ex:
assert a == 42
else:
assert a is getattr(object, meth_name)
def assert_none_set(cls, ex):
__tracebackhide__ = True
for m in ("le", "lt", "ge", "gt"):
assert_not_set(cls, ex, "__" + m + "__")
@attr.s(auto_detect=True, slots=slots, frozen=frozen)
class LE:
__le__ = 42
@attr.s(auto_detect=True, slots=slots, frozen=frozen)
class LT:
__lt__ = 42
@attr.s(auto_detect=True, slots=slots, frozen=frozen)
class GE:
__ge__ = 42
@attr.s(auto_detect=True, slots=slots, frozen=frozen)
class GT:
__gt__ = 42
assert_none_set(LE, "__le__")
assert_none_set(LT, "__lt__")
assert_none_set(GE, "__ge__")
assert_none_set(GT, "__gt__")
@pytest.mark.parametrize("slots", [True, False])
@pytest.mark.parametrize("frozen", [True, False])
def test_override_init(self, slots, frozen):
"""
If init=True is passed, ignore __init__.
"""
@attr.s(init=True, auto_detect=True, slots=slots, frozen=frozen)
class C:
x = attr.ib()
def __init__(self):
pytest.fail("should not be called")
assert C(1) == C(1)
@pytest.mark.parametrize("slots", [True, False])
@pytest.mark.parametrize("frozen", [True, False])
def test_override_repr(self, slots, frozen):
"""
If repr=True is passed, ignore __repr__.
"""
@attr.s(repr=True, auto_detect=True, slots=slots, frozen=frozen)
class C:
x = attr.ib()
def __repr__(self):
pytest.fail("should not be called")
assert "C(x=1)" == repr(C(1))
@pytest.mark.parametrize("slots", [True, False])
@pytest.mark.parametrize("frozen", [True, False])
def test_override_hash(self, slots, frozen):
"""
If hash=True is passed, ignore __hash__.
"""
@attr.s(hash=True, auto_detect=True, slots=slots, frozen=frozen)
class C:
x = attr.ib()
def __hash__(self):
pytest.fail("should not be called")
assert hash(C(1))
@pytest.mark.parametrize("slots", [True, False])
@pytest.mark.parametrize("frozen", [True, False])
def test_override_eq(self, slots, frozen):
"""
If eq=True is passed, ignore __eq__ and __ne__.
"""
@attr.s(eq=True, auto_detect=True, slots=slots, frozen=frozen)
class C:
x = attr.ib()
def __eq__(self, o):
pytest.fail("should not be called")
def __ne__(self, o):
pytest.fail("should not be called")
assert C(1) == C(1)
@pytest.mark.parametrize("slots", [True, False])
@pytest.mark.parametrize("frozen", [True, False])
@pytest.mark.parametrize(
"eq,order,cmp",
[
(True, None, None),
(True, True, None),
(None, True, None),
(None, None, True),
],
)
def test_override_order(self, slots, frozen, eq, order, cmp):
"""
If order=True is passed, ignore __le__, __lt__, __gt__, __ge__.
eq=True and cmp=True both imply order=True so test it too.
"""
def meth(self, o):
pytest.fail("should not be called")
@attr.s(
cmp=cmp,
order=order,
eq=eq,
auto_detect=True,
slots=slots,
frozen=frozen,
)
class C:
x = attr.ib()
__le__ = __lt__ = __gt__ = __ge__ = meth
assert C(1) < C(2)
assert C(1) <= C(2)
assert C(2) > C(1)
assert C(2) >= C(1)
@pytest.mark.parametrize("slots", [True, False])
@pytest.mark.parametrize("first", [True, False])
def test_total_ordering(self, slots, first):
"""
functools.total_ordering works as expected if an order method and an eq
method are detected.
Ensure the order doesn't matter.
"""
class C:
x = attr.ib()
own_eq_called = attr.ib(default=False)
own_le_called = attr.ib(default=False)
def __eq__(self, o):
self.own_eq_called = True
return self.x == o.x
def __le__(self, o):
self.own_le_called = True
return self.x <= o.x
if first:
C = functools.total_ordering(
attr.s(auto_detect=True, slots=slots)(C)
)
else:
C = attr.s(auto_detect=True, slots=slots)(
functools.total_ordering(C)
)
c1, c2 = C(1), C(2)
assert c1 < c2
assert c1.own_le_called
c1, c2 = C(1), C(2)
assert c2 > c1
assert c2.own_le_called
c1, c2 = C(1), C(2)
assert c2 != c1
assert c1 == c1
assert c1.own_eq_called
@pytest.mark.parametrize("slots", [True, False])
def test_detects_setstate_getstate(self, slots):
"""
__getstate__ and __setstate__ are not overwritten if either is present.
"""
@attr.s(slots=slots, auto_detect=True)
class C:
def __getstate__(self):
return ("hi",)
assert None is getattr(C(), "__setstate__", None)
@attr.s(slots=slots, auto_detect=True)
class C:
called = attr.ib(False)
def __setstate__(self, state):
self.called = True
i = C()
assert False is i.called
i.__setstate__(())
assert True is i.called
assert None is getattr(C(), "__getstate__", None)
@pytest.mark.skipif(PY310, reason="Pre-3.10 only.")
def test_match_args_pre_310(self):
"""
__match_args__ is not created on Python versions older than 3.10.
"""
@attr.s
class C:
a = attr.ib()
assert None is getattr(C, "__match_args__", None)
@pytest.mark.skipif(not PY310, reason="Structural pattern matching is 3.10+")
class TestMatchArgs:
"""
Tests for match_args and __match_args__ generation.
"""
def test_match_args(self):
"""
__match_args__ is created by default on Python 3.10.
"""
@attr.define
class C:
a = attr.field()
assert ("a",) == C.__match_args__
def test_explicit_match_args(self):
"""
A custom __match_args__ set is not overwritten.
"""
ma = ()
@attr.define
class C:
a = attr.field()
__match_args__ = ma
assert C(42).__match_args__ is ma
@pytest.mark.parametrize("match_args", [True, False])
def test_match_args_attr_set(self, match_args):
"""
__match_args__ is set depending on match_args.
"""
@attr.define(match_args=match_args)
class C:
a = attr.field()
if match_args:
assert hasattr(C, "__match_args__")
else:
assert not hasattr(C, "__match_args__")
def test_match_args_kw_only(self):
"""
kw_only classes don't generate __match_args__.
kw_only fields are not included in __match_args__.
"""
@attr.define
class C:
a = attr.field(kw_only=True)
b = attr.field()
assert C.__match_args__ == ("b",)
@attr.define(kw_only=True)
class C:
a = attr.field()
b = attr.field()
assert C.__match_args__ == ()
def test_match_args_argument(self):
"""
match_args being False with inheritance.
"""
@attr.define(match_args=False)
class X:
a = attr.field()
assert "__match_args__" not in X.__dict__
@attr.define(match_args=False)
class Y:
a = attr.field()
__match_args__ = ("b",)
assert Y.__match_args__ == ("b",)
@attr.define(match_args=False)
class Z(Y):
z = attr.field()
assert Z.__match_args__ == ("b",)
@attr.define
class A:
a = attr.field()
z = attr.field()
@attr.define(match_args=False)
class B(A):
b = attr.field()
assert B.__match_args__ == ("a", "z")
def test_make_class(self):
"""
match_args generation with make_class.
"""
C1 = make_class("C1", ["a", "b"])
assert ("a", "b") == C1.__match_args__
C1 = make_class("C1", ["a", "b"], match_args=False)
assert not hasattr(C1, "__match_args__")
C1 = make_class("C1", ["a", "b"], kw_only=True)
assert () == C1.__match_args__
C1 = make_class("C1", {"a": attr.ib(kw_only=True), "b": attr.ib()})
assert ("b",) == C1.__match_args__