niceSOFT/python3-attrs: Python Classes Without Boilerplate

tests/test_make.py
2 500 строк64 KB
Hynek Schlawack
Purge stale Python 2/3 mentions
18 дек 2022, 12:54
18 дек 2022, 12:5459a445e
# 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
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, alias=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=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):
        """
        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):
        """
        __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

    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)

    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", 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 (
            f"{object!r} is not an attrs-decorated class."
        ) == 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 (
            f"{object!r} is not an attrs-decorated class."
        ) == 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, 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",
            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 ln: sorted(ln, 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, 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 TestInitAlias:
    """
    Tests for Attribute alias handling.
    """

    def test_default_and_specify(self):
        """
        alias is present on the Attributes returned from attr.fields.

        If left unspecified, it defaults to standard private-attribute
        handling.  If specified, it passes through the explicit alias.
        """

        # alias is None by default on _CountingAttr
        default_counting = attr.ib()
        assert default_counting.alias is None

        override_counting = attr.ib(alias="specified")
        assert override_counting.alias == "specified"

        @attr.s
        class Cases:
            public_default = attr.ib()
            _private_default = attr.ib()
            __dunder_default__ = attr.ib()

            public_override = attr.ib(alias="public")
            _private_override = attr.ib(alias="_private")
            __dunder_override__ = attr.ib(alias="__dunder__")

        cases = attr.fields_dict(Cases)

        # Default applies private-name mangling logic
        assert cases["public_default"].name == "public_default"
        assert cases["public_default"].alias == "public_default"

        assert cases["_private_default"].name == "_private_default"
        assert cases["_private_default"].alias == "private_default"

        assert cases["__dunder_default__"].name == "__dunder_default__"
        assert cases["__dunder_default__"].alias == "dunder_default__"

        # Override is passed through
        assert cases["public_override"].name == "public_override"
        assert cases["public_override"].alias == "public"

        assert cases["_private_override"].name == "_private_override"
        assert cases["_private_override"].alias == "_private"

        assert cases["__dunder_override__"].name == "__dunder_override__"
        assert cases["__dunder_override__"].alias == "__dunder__"

        # And aliases are applied to the __init__ signature
        example = Cases(
            public_default=1,
            private_default=2,
            dunder_default__=3,
            public=4,
            _private=5,
            __dunder__=6,
        )

        assert example.public_default == 1
        assert example._private_default == 2
        assert example.__dunder_default__ == 3
        assert example.public_override == 4
        assert example._private_override == 5
        assert example.__dunder_override__ == 6

    def test_evolve(self):
        """
        attr.evolve uses Attribute.alias to determine parameter names.
        """

        @attr.s
        class EvolveCase:
            _override = attr.ib(alias="_override")
            __mangled = attr.ib()
            __dunder__ = attr.ib()

        org = EvolveCase(1, 2, 3)

        # Previous behavior of evolve as broken for double-underscore
        # passthrough, and would raise here due to mis-mapping the __dunder__
        # alias
        assert attr.evolve(org) == org

        # evolve uses the alias to match __init__ signature
        assert attr.evolve(
            org,
            _override=0,
        ) == EvolveCase(0, 2, 3)

        # and properly passes through dunders and mangles
        assert attr.evolve(
            org,
            EvolveCase__mangled=4,
            dunder__=5,
        ) == EvolveCase(1, 4, 5)


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.
        """

        @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 = f"Method generated by attrs for class {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__")
        )

    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__

    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

    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))

    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))

    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))

    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)

    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__")

    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)

    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))

    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))

    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(
        "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("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

    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 getattr(object, "__setstate__", 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 getattr(object, "__getstate__", 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__