67 lines
1.3 KiB
Python
67 lines
1.3 KiB
Python
# SPDX-License-Identifier: MIT
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"""
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Tests for `__init_subclass__` related functionality.
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"""
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import attr
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def test_init_subclass_vanilla(slots):
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"""
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`super().__init_subclass__` can be used if the subclass is not an attrs
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class both with dict and slotted classes.
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"""
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@attr.s(slots=slots)
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class Base:
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def __init_subclass__(cls, param, **kw):
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super().__init_subclass__(**kw)
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cls.param = param
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class Vanilla(Base, param="foo"):
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pass
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assert "foo" == Vanilla().param
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def test_init_subclass_attrs():
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"""
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`__init_subclass__` works with attrs classes as long as slots=False.
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"""
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@attr.s(slots=False)
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class Base:
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def __init_subclass__(cls, param, **kw):
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super().__init_subclass__(**kw)
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cls.param = param
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@attr.s
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class Attrs(Base, param="foo"):
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pass
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assert "foo" == Attrs().param
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def test_init_subclass_slots_workaround():
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"""
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`__init_subclass__` works with modern APIs if care is taken around classes
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existing twice.
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"""
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subs = {}
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@attr.define
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class Base:
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def __init_subclass__(cls):
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subs[cls.__qualname__] = cls
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@attr.define
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class Sub1(Base):
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x: int
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@attr.define
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class Sub2(Base):
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y: int
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assert (Sub1, Sub2) == tuple(subs.values())
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