""" Tests for `attr._make`. """ from __future__ import absolute_import, division, print_function import copy import gc import inspect import itertools import sys from operator import attrgetter import pytest from hypothesis import given from hypothesis.strategies import booleans, integers, lists, sampled_from, text import attr from attr import _config from attr._compat import PY2, ordered_dict from attr._make import ( Attribute, Factory, _AndValidator, _Attributes, _ClassBuilder, _CountingAttr, _transform_attrs, and_, fields, fields_dict, make_class, validate, ) from attr.exceptions import ( DefaultAlreadySetError, NotAnAttrsClassError, PythonTooOldError, ) from .strategies import ( gen_attr_names, list_of_attrs, 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(object): """ Tests for `attr`. """ def test_returns_Attr(self): """ Returns an instance of _CountingAttr. """ a = attr.ib() assert isinstance(a, _CountingAttr) def test_validators_lists_to_wrapped_tuples(self): """ If a list is passed as validator, it's just converted to a tuple. """ def v1(_, __): pass def v2(_, __): pass a = attr.ib(validator=[v1, v2]) assert _AndValidator((v1, v2)) == a._validator def test_validator_decorator_single(self): """ If _CountingAttr.validator is used as a decorator and there is no decorator set, the decorated method is used as the validator. """ a = attr.ib() @a.validator def v(): pass assert v == a._validator @pytest.mark.parametrize( "wrap", [lambda v: v, lambda v: [v], lambda v: and_(v)] ) def test_validator_decorator(self, wrap): """ If _CountingAttr.validator is used as a decorator and there is already a decorator set, the decorators are composed using `and_`. """ def v(_, __): pass a = attr.ib(validator=wrap(v)) @a.validator def v2(self, _, __): pass assert _AndValidator((v, v2)) == a._validator def test_default_decorator_already_set(self): """ Raise DefaultAlreadySetError if the decorator is used after a default has been set. """ a = attr.ib(default=42) with pytest.raises(DefaultAlreadySetError): @a.default def f(self): pass def test_default_decorator_sets(self): """ Decorator wraps the method in a Factory with pass_self=True and sets the default. """ a = attr.ib() @a.default def f(self): pass assert Factory(f, True) == a._default def make_tc(): class TransformC(object): z = attr.ib() y = attr.ib() x = attr.ib() a = 42 return TransformC class TestTransformAttrs(object): """ Tests for `_transform_attrs`. """ def test_no_modifications(self): """ Does not attach __attrs_attrs__ to the class. """ C = make_tc() _transform_attrs(C, None, False, False) assert None is getattr(C, "__attrs_attrs__", None) def test_normal(self): """ Transforms every `_CountingAttr` and leaves others (a) be. """ C = make_tc() attrs, _, _ = _transform_attrs(C, None, False, False) assert ["z", "y", "x"] == [a.name for a in attrs] def test_empty(self): """ No attributes works as expected. """ @attr.s class C(object): pass assert _Attributes(((), [], {})) == _transform_attrs( C, None, False, False ) 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) 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(object): x = attr.ib(default=None) y = attr.ib() with pytest.raises(ValueError) as e: _transform_attrs(C, None, False, False) assert ( "No mandatory attributes allowed after an attribute with a " "default value or factory. Attribute in question: Attribute" "(name='y', default=NOTHING, validator=None, repr=True, " "cmp=True, hash=None, init=True, metadata=mappingproxy({}), " "type=None, converter=None, kw_only=False)", ) == 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 preceed mandatory attributes. Updates in the subclass *don't* affect the base class attributes. """ @attr.s class B(object): 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) 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(object): z = attr.ib() class C(Base): y = attr.ib() attrs, base_attrs, _ = _transform_attrs( C, {"x": attr.ib()}, False, False ) 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(object): 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(object): pass assert "C(a=1, b=2)" == repr(C()) def test_multiple_inheritance(self): """ Order of attributes doesn't get mixed up by multiple inheritance. See #285 """ @attr.s class A(object): 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()) class TestAttributes(object): """ Tests for the `attrs`/`attr.s` class decorator. """ @pytest.mark.skipif(not PY2, reason="No old-style classes in Py3") def test_catches_old_style(self): """ Raises TypeError on old-style classes. """ with pytest.raises(TypeError) as e: @attr.s class C: pass assert ("attrs only works with new-style classes.",) == e.value.args def test_sets_attrs(self): """ Sets the `__attrs_attrs__` class attribute with a list of `Attribute`s. """ @attr.s class C(object): x = attr.ib() assert "x" == C.__attrs_attrs__[0].name assert all(isinstance(a, Attribute) for a in C.__attrs_attrs__) def test_empty(self): """ No attributes, no problems. """ @attr.s class C3(object): pass assert "C3()" == repr(C3()) assert C3() == C3() @given(attr=attrs_st, attr_name=sampled_from(Attribute.__slots__)) def test_immutable(self, attr, attr_name): """ Attribute instances are immutable. """ with pytest.raises(AttributeError): setattr(attr, attr_name, 1) @pytest.mark.parametrize( "method_name", ["__repr__", "__eq__", "__hash__", "__init__"] ) def test_adds_all_by_default(self, method_name): """ If no further arguments are supplied, all add_XXX functions except add_hash are applied. __hash__ is set to None. """ # Set the method name to a sentinel and check whether it has been # overwritten afterwards. sentinel = object() class C(object): x = attr.ib() setattr(C, method_name, sentinel) C = attr.s(C) meth = getattr(C, method_name) assert sentinel != meth if method_name == "__hash__": assert meth is None @pytest.mark.parametrize( "arg_name, method_name", [ ("repr", "__repr__"), ("cmp", "__eq__"), ("hash", "__hash__"), ("init", "__init__"), ], ) def test_respects_add_arguments(self, arg_name, method_name): """ If a certain `add_XXX` is `False`, `__XXX__` is not added to the class. """ # Set the method name to a sentinel and check whether it has been # overwritten afterwards. sentinel = object() am_args = {"repr": True, "cmp": True, "hash": True, "init": True} am_args[arg_name] = False class C(object): x = attr.ib() setattr(C, method_name, sentinel) C = attr.s(**am_args)(C) assert sentinel == getattr(C, method_name) @pytest.mark.skipif(PY2, reason="__qualname__ is PY3-only.") @given(slots_outer=booleans(), slots_inner=booleans()) def test_repr_qualname(self, slots_outer, slots_inner): """ On Python 3, the name in repr is the __qualname__. """ @attr.s(slots=slots_outer) class C(object): @attr.s(slots=slots_inner) class D(object): pass assert "C.D()" == repr(C.D()) assert "GC.D()" == repr(GC.D()) @given(slots_outer=booleans(), slots_inner=booleans()) def test_repr_fake_qualname(self, slots_outer, slots_inner): """ Setting repr_ns overrides a potentially guessed namespace. """ @attr.s(slots=slots_outer) class C(object): @attr.s(repr_ns="C", slots=slots_inner) class D(object): pass assert "C.D()" == repr(C.D()) @pytest.mark.skipif(PY2, reason="__qualname__ is PY3-only.") @given(slots_outer=booleans(), slots_inner=booleans()) def test_name_not_overridden(self, slots_outer, slots_inner): """ On Python 3, __name__ is different from __qualname__. """ @attr.s(slots=slots_outer) class C(object): @attr.s(slots=slots_inner) class D(object): pass assert C.D.__name__ == "D" assert C.D.__qualname__ == C.__qualname__ + ".D" @given(with_validation=booleans()) def test_post_init(self, with_validation, monkeypatch): """ Verify that __attrs_post_init__ gets called if defined. """ monkeypatch.setattr(_config, "_run_validators", with_validation) @attr.s class C(object): x = attr.ib() y = attr.ib() def __attrs_post_init__(self2): self2.z = self2.x + self2.y c = C(x=10, y=20) assert 30 == getattr(c, "z", None) def test_types(self): """ Sets the `Attribute.type` attr from type argument. """ @attr.s class C(object): x = attr.ib(type=int) y = attr.ib(type=str) z = attr.ib() assert int is fields(C).x.type assert str is fields(C).y.type assert None is fields(C).z.type @pytest.mark.parametrize("slots", [True, False]) def test_clean_class(self, slots): """ Attribute definitions do not appear on the class body after @attr.s. """ @attr.s(slots=slots) class C(object): x = attr.ib() x = getattr(C, "x", None) assert not isinstance(x, _CountingAttr) def test_factory_sugar(self): """ Passing factory=f is syntactic sugar for passing default=Factory(f). """ @attr.s class C(object): 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(object): 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(object): x = attr.ib(factory=Factory(list)) @pytest.mark.skipif(PY2, reason="keyword-only arguments are PY3-only.") class TestKeywordOnlyAttributes(object): """ Tests for keyword-only attributes. """ def test_adds_keyword_only_arguments(self): """ Attributes can be added as keyword-only. """ @attr.s class C(object): 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(object): 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(object): 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_conflicting_keyword_only_attributes(self): """ Raises `ValueError` if keyword-only attributes are followed by regular (non keyword-only) attributes. """ class C(object): x = attr.ib(kw_only=True) y = attr.ib() with pytest.raises(ValueError) as e: _transform_attrs(C, None, False, False) assert ( "Non keyword-only attributes are not allowed after a " "keyword-only attribute (unless they are init=False). " "Attribute in question: Attribute" "(name='y', default=NOTHING, validator=None, repr=True, " "cmp=True, hash=None, init=True, metadata=mappingproxy({}), " "type=None, converter=None, kw_only=False)", ) == e.value.args 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(object): 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(object): 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" @pytest.mark.skipif(not PY2, reason="PY2-specific keyword-only error behavior") class TestKeywordOnlyAttributesOnPy2(object): """ Tests for keyword-only attribute behavior on py2. """ def test_syntax_error(self): """ Keyword-only attributes raise Syntax error on ``__init__`` generation. """ with pytest.raises(PythonTooOldError): @attr.s(kw_only=True) class ClassLevel(object): a = attr.ib() with pytest.raises(PythonTooOldError): @attr.s() class AttrLevel(object): a = attr.ib(kw_only=True) def test_no_init(self): """ Keyworld-only is a no-op, not any error, if ``init=false``. """ @attr.s(kw_only=True, init=False) class ClassLevel(object): a = attr.ib() @attr.s(init=False) class AttrLevel(object): a = attr.ib(kw_only=True) @attr.s class GC(object): @attr.s class D(object): pass class TestMakeClass(object): """ Tests for `make_class`. """ @pytest.mark.parametrize("ls", [list, tuple]) def test_simple(self, ls): """ Passing a list of strings creates attributes with default args. """ C1 = make_class("C1", ls(["a", "b"])) @attr.s class C2(object): a = attr.ib() b = attr.ib() assert C1.__attrs_attrs__ == C2.__attrs_attrs__ def test_dict(self): """ Passing a dict of name: _CountingAttr creates an equivalent class. """ C1 = make_class( "C1", {"a": attr.ib(default=42), "b": attr.ib(default=None)} ) @attr.s class C2(object): a = attr.ib(default=42) b = attr.ib(default=None) assert C1.__attrs_attrs__ == C2.__attrs_attrs__ def test_attr_args(self): """ attributes_arguments are passed to attributes """ C = make_class("C", ["x"], repr=False) assert repr(C(1)).startswith(" 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(object): """ Tests for `_ClassBuilder`. """ def test_repr_str(self): """ Trying to add a `__str__` without having a `__repr__` raises a ValueError. """ with pytest.raises(ValueError) as ei: make_class("C", {}, repr=False, str=True) assert ( "__str__ can only be generated if a __repr__ exists.", ) == ei.value.args def test_repr(self): """ repr of builder itself makes sense. """ class C(object): pass b = _ClassBuilder( C, None, True, True, False, False, False, False, False ) assert "<_ClassBuilder(cls=C)>" == repr(b) def test_returns_self(self): """ All methods return the builder for chaining. """ class C(object): x = attr.ib() b = _ClassBuilder( C, None, True, True, False, False, False, False, False ) cls = ( b.add_cmp() .add_hash() .add_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(object): def organic(self): pass meth = getattr(C, meth_name) assert meth_name == meth.__name__ assert C.organic.__module__ == meth.__module__ if not PY2: organic_prefix = C.organic.__qualname__.rsplit(".", 1)[0] assert organic_prefix + "." + meth_name == meth.__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(object): pass b = _ClassBuilder( C, these=None, slots=False, frozen=False, weakref_slot=True, auto_attribs=False, is_exc=False, kw_only=False, cache_hash=False, ) 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(object): __weakref__ = attr.ib( init=False, hash=False, repr=False, cmp=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(object): 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__() class TestMakeCmp: """ Tests for _make_cmp(). """ @pytest.mark.parametrize( "op", ["__%s__" % (op,) for op in ("lt", "le", "gt", "ge")] ) def test_subclasses_deprecated(self, recwarn, op): """ Calling comparison methods on subclasses raises a deprecation warning; calling them on identical classes does not.. """ @attr.s class A(object): a = attr.ib() @attr.s class B(A): pass getattr(A(42), op)(A(42)) getattr(B(42), op)(B(42)) assert [] == recwarn.list getattr(A(42), op)(B(42)) w = recwarn.pop() assert [] == recwarn.list assert isinstance(w.message, DeprecationWarning) assert ( "Comparision of subclasses using %s is deprecated and will be " "removed in 2019." % (op,) ) == w.message.args[0]