from __future__ import absolute_import, division, print_function import pytest import attr from attr._compat import TYPE from attr._make import Attribute, NOTHING @attr.s class C1(object): x = attr.ib(validator=attr.validators.instance_of(int)) y = attr.ib() @attr.s(slots=True) class C1Slots(object): x = attr.ib(validator=attr.validators.instance_of(int)) y = attr.ib() foo = None @attr.s class C2(object): x = attr.ib(default=foo) y = attr.ib(default=attr.Factory(list)) @attr.s(slots=True) class C2Slots(object): x = attr.ib(default=foo) y = attr.ib(default=attr.Factory(list)) @attr.s class Super(object): x = attr.ib() def meth(self): return self.x @attr.s(slots=True) class SuperSlots(object): x = attr.ib() def meth(self): return self.x @attr.s class Sub(Super): y = attr.ib() @attr.s(slots=True) class SubSlots(SuperSlots): y = attr.ib() class TestDarkMagic(object): """ Integration tests. """ @pytest.mark.parametrize("class_", [C2, C2Slots]) def test_fields(self, class_): """ `attr.fields` works. """ assert ( Attribute(name="x", default=foo, validator=None, repr=True, cmp=True, hash=True, init=True), Attribute(name="y", default=attr.Factory(list), validator=None, repr=True, cmp=True, hash=True, init=True), ) == attr.fields(class_) @pytest.mark.parametrize("class_", [C1, C1Slots]) def test_asdict(self, class_): """ `attr.asdict` works. """ assert { "x": 1, "y": 2, } == attr.asdict(class_(x=1, y=2)) @pytest.mark.parametrize("class_", [C1, C1Slots]) def test_validator(self, class_): """ `instance_of` raises `TypeError` on type mismatch. """ with pytest.raises(TypeError) as e: class_("1", 2) # Using C1 explicitly, since slot classes don't support this. assert ( "'x' must be <{type} 'int'> (got '1' that is a <{type} " "'str'>).".format(type=TYPE), C1.x, int, "1", ) == e.value.args @pytest.mark.parametrize("slots", [True, False]) def test_renaming(self, slots): """ Private members are renamed but only in `__init__`. """ @attr.s(slots=slots) class C3(object): _x = attr.ib() assert "C3(_x=1)" == repr(C3(x=1)) @pytest.mark.parametrize("slots", [True, False]) def test_programmatic(self, slots): """ `attr.make_class` works. """ PC = attr.make_class("PC", ["a", "b"], slots=slots) assert ( Attribute(name="a", default=NOTHING, validator=None, repr=True, cmp=True, hash=True, init=True), Attribute(name="b", default=NOTHING, validator=None, repr=True, cmp=True, hash=True, init=True), ) == attr.fields(PC) @pytest.mark.parametrize("class_", [Sub, SubSlots]) def test_subclassing_with_extra_attrs(self, class_): """ Sub-classing (where the subclass has extra attrs) does what you'd hope for. """ obj = object() i = class_(x=obj, y=2) assert i.x is i.meth() is obj assert i.y == 2 if class_ is Sub: assert "Sub(x={obj}, y=2)".format(obj=obj) == repr(i) else: assert "SubSlots(x={obj}, y=2)".format(obj=obj) == repr(i) @pytest.mark.parametrize("base", [Super, SuperSlots]) def test_subclass_without_extra_attrs(self, base): """ Sub-classing (where the subclass does not have extra attrs) still behaves the same as a subclss with extra attrs. """ class Sub2(base): pass obj = object() i = Sub2(x=obj) assert i.x is i.meth() is obj assert "Sub2(x={obj})".format(obj=obj) == repr(i)