astroid/tests/unittest_brain_dataclasses.py

686 lines
17 KiB
Python

import pytest
import astroid
from astroid import bases, nodes
from astroid.const import PY37_PLUS
from astroid.exceptions import InferenceError
from astroid.util import Uninferable
if not PY37_PLUS:
pytest.skip("Dataclasses were added in 3.7", allow_module_level=True)
parametrize_module = pytest.mark.parametrize(
("module",), (["dataclasses"], ["pydantic.dataclasses"], ["marshmallow_dataclass"])
)
@parametrize_module
def test_inference_attribute_no_default(module: str):
"""Test inference of dataclass attribute with no default.
Note that the argument to the constructor is ignored by the inference.
"""
klass, instance = astroid.extract_node(
f"""
from {module} import dataclass
@dataclass
class A:
name: str
A.name #@
A('hi').name #@
"""
)
with pytest.raises(InferenceError):
klass.inferred()
inferred = instance.inferred()
assert len(inferred) == 1
assert isinstance(inferred[0], bases.Instance)
assert inferred[0].name == "str"
@parametrize_module
def test_inference_non_field_default(module: str):
"""Test inference of dataclass attribute with a non-field default."""
klass, instance = astroid.extract_node(
f"""
from {module} import dataclass
@dataclass
class A:
name: str = 'hi'
A.name #@
A().name #@
"""
)
inferred = klass.inferred()
assert len(inferred) == 1
assert isinstance(inferred[0], nodes.Const)
assert inferred[0].value == "hi"
inferred = instance.inferred()
assert len(inferred) == 2
assert isinstance(inferred[0], nodes.Const)
assert inferred[0].value == "hi"
assert isinstance(inferred[1], bases.Instance)
assert inferred[1].name == "str"
@parametrize_module
def test_inference_field_default(module: str):
"""Test inference of dataclass attribute with a field call default
(default keyword argument given)."""
klass, instance = astroid.extract_node(
f"""
from {module} import dataclass
from dataclasses import field
@dataclass
class A:
name: str = field(default='hi')
A.name #@
A().name #@
"""
)
inferred = klass.inferred()
assert len(inferred) == 1
assert isinstance(inferred[0], nodes.Const)
assert inferred[0].value == "hi"
inferred = instance.inferred()
assert len(inferred) == 2
assert isinstance(inferred[0], nodes.Const)
assert inferred[0].value == "hi"
assert isinstance(inferred[1], bases.Instance)
assert inferred[1].name == "str"
@parametrize_module
def test_inference_field_default_factory(module: str):
"""Test inference of dataclass attribute with a field call default
(default_factory keyword argument given)."""
klass, instance = astroid.extract_node(
f"""
from {module} import dataclass
from dataclasses import field
@dataclass
class A:
name: list = field(default_factory=list)
A.name #@
A().name #@
"""
)
inferred = klass.inferred()
assert len(inferred) == 1
assert isinstance(inferred[0], nodes.List)
assert inferred[0].elts == []
inferred = instance.inferred()
assert len(inferred) == 2
assert isinstance(inferred[0], nodes.List)
assert inferred[0].elts == []
assert isinstance(inferred[1], bases.Instance)
assert inferred[1].name == "list"
@parametrize_module
def test_inference_method(module: str):
"""Test inference of dataclass attribute within a method,
with a default_factory field.
Based on https://github.com/PyCQA/pylint/issues/2600
"""
node = astroid.extract_node(
f"""
from typing import Dict
from {module} import dataclass
from dataclasses import field
@dataclass
class TestClass:
foo: str
bar: str
baz_dict: Dict[str, str] = field(default_factory=dict)
def some_func(self) -> None:
f = self.baz_dict.items #@
for key, value in f():
print(key)
print(value)
"""
)
inferred = next(node.value.infer())
assert isinstance(inferred, bases.BoundMethod)
@parametrize_module
def test_inference_no_annotation(module: str):
"""Test that class variables without type annotations are not
turned into instance attributes.
"""
class_def, klass, instance = astroid.extract_node(
f"""
from {module} import dataclass
@dataclass
class A:
name = 'hi'
A #@
A.name #@
A().name #@
"""
)
inferred = next(class_def.infer())
assert isinstance(inferred, nodes.ClassDef)
assert inferred.instance_attrs == {}
# Both the class and instance can still access the attribute
for node in (klass, instance):
assert isinstance(node, nodes.NodeNG)
inferred = node.inferred()
assert len(inferred) == 1
assert isinstance(inferred[0], nodes.Const)
assert inferred[0].value == "hi"
@parametrize_module
def test_inference_class_var(module: str):
"""Test that class variables with a ClassVar type annotations are not
turned into instance attributes.
"""
class_def, klass, instance = astroid.extract_node(
f"""
from {module} import dataclass
from typing import ClassVar
@dataclass
class A:
name: ClassVar[str] = 'hi'
A #@
A.name #@
A().name #@
"""
)
inferred = next(class_def.infer())
assert isinstance(inferred, nodes.ClassDef)
assert inferred.instance_attrs == {}
# Both the class and instance can still access the attribute
for node in (klass, instance):
assert isinstance(node, nodes.NodeNG)
inferred = node.inferred()
assert len(inferred) == 1
assert isinstance(inferred[0], nodes.Const)
assert inferred[0].value == "hi"
@parametrize_module
def test_inference_init_var(module: str):
"""Test that class variables with InitVar type annotations are not
turned into instance attributes.
"""
class_def, klass, instance = astroid.extract_node(
f"""
from {module} import dataclass
from dataclasses import InitVar
@dataclass
class A:
name: InitVar[str] = 'hi'
A #@
A.name #@
A().name #@
"""
)
inferred = next(class_def.infer())
assert isinstance(inferred, nodes.ClassDef)
assert inferred.instance_attrs == {}
# Both the class and instance can still access the attribute
for node in (klass, instance):
assert isinstance(node, nodes.NodeNG)
inferred = node.inferred()
assert len(inferred) == 1
assert isinstance(inferred[0], nodes.Const)
assert inferred[0].value == "hi"
@parametrize_module
def test_inference_generic_collection_attribute(module: str):
"""Test that an attribute with a generic collection type from the
typing module is inferred correctly.
"""
attr_nodes = astroid.extract_node(
f"""
from {module} import dataclass
from dataclasses import field
import typing
@dataclass
class A:
dict_prop: typing.Dict[str, str]
frozenset_prop: typing.FrozenSet[str]
list_prop: typing.List[str]
set_prop: typing.Set[str]
tuple_prop: typing.Tuple[int, str]
a = A({{}}, frozenset(), [], set(), (1, 'hi'))
a.dict_prop #@
a.frozenset_prop #@
a.list_prop #@
a.set_prop #@
a.tuple_prop #@
"""
)
names = (
"Dict",
"FrozenSet",
"List",
"Set",
"Tuple",
)
for node, name in zip(attr_nodes, names):
inferred = next(node.infer())
assert isinstance(inferred, bases.Instance)
assert inferred.name == name
@pytest.mark.parametrize(
("module", "typing_module"),
[
("dataclasses", "typing"),
("pydantic.dataclasses", "typing"),
("pydantic.dataclasses", "collections.abc"),
("marshmallow_dataclass", "typing"),
("marshmallow_dataclass", "collections.abc"),
],
)
def test_inference_callable_attribute(module: str, typing_module: str):
"""Test that an attribute with a Callable annotation is inferred as Uninferable.
See issue #1129 and PyCQA/pylint#4895
"""
instance = astroid.extract_node(
f"""
from {module} import dataclass
from {typing_module} import Any, Callable
@dataclass
class A:
enabled: Callable[[Any], bool]
A(lambda x: x == 42).enabled #@
"""
)
inferred = next(instance.infer())
assert inferred is Uninferable
@parametrize_module
def test_inference_inherited(module: str):
"""Test that an attribute is inherited from a superclass dataclass."""
klass1, instance1, klass2, instance2 = astroid.extract_node(
f"""
from {module} import dataclass
@dataclass
class A:
value: int
name: str = "hi"
@dataclass
class B(A):
new_attr: bool = True
B.value #@
B(1).value #@
B.name #@
B(1).name #@
"""
)
with pytest.raises(InferenceError): # B.value is not defined
klass1.inferred()
inferred = instance1.inferred()
assert isinstance(inferred[0], bases.Instance)
assert inferred[0].name == "int"
inferred = klass2.inferred()
assert len(inferred) == 1
assert isinstance(inferred[0], nodes.Const)
assert inferred[0].value == "hi"
inferred = instance2.inferred()
assert len(inferred) == 2
assert isinstance(inferred[0], nodes.Const)
assert inferred[0].value == "hi"
assert isinstance(inferred[1], bases.Instance)
assert inferred[1].name == "str"
def test_pydantic_field() -> None:
"""Test that pydantic.Field attributes are currently Uninferable.
(Eventually, we can extend the brain to support pydantic.Field)
"""
klass, instance = astroid.extract_node(
"""
from pydantic import Field
from pydantic.dataclasses import dataclass
@dataclass
class A:
name: str = Field("hi")
A.name #@
A().name #@
"""
)
inferred = klass.inferred()
assert len(inferred) == 1
assert inferred[0] is Uninferable
inferred = instance.inferred()
assert len(inferred) == 2
assert inferred[0] is Uninferable
assert isinstance(inferred[1], bases.Instance)
assert inferred[1].name == "str"
@parametrize_module
def test_init_empty(module: str):
"""Test init for a dataclass with no attributes"""
node = astroid.extract_node(
f"""
from {module} import dataclass
@dataclass
class A:
pass
A.__init__ #@
"""
)
init = next(node.infer())
assert [a.name for a in init.args.args] == ["self"]
@parametrize_module
def test_init_no_defaults(module: str):
"""Test init for a dataclass with attributes and no defaults"""
node = astroid.extract_node(
f"""
from {module} import dataclass
from typing import List
@dataclass
class A:
x: int
y: str
z: List[bool]
A.__init__ #@
"""
)
init = next(node.infer())
assert [a.name for a in init.args.args] == ["self", "x", "y", "z"]
assert [a.as_string() if a else None for a in init.args.annotations] == [
None,
"int",
"str",
"List[bool]",
]
@parametrize_module
def test_init_defaults(module: str):
"""Test init for a dataclass with attributes and some defaults"""
node = astroid.extract_node(
f"""
from {module} import dataclass
from dataclasses import field
from typing import List
@dataclass
class A:
w: int
x: int = 10
y: str = field(default="hi")
z: List[bool] = field(default_factory=list)
A.__init__ #@
"""
)
init = next(node.infer())
assert [a.name for a in init.args.args] == ["self", "w", "x", "y", "z"]
assert [a.as_string() if a else None for a in init.args.annotations] == [
None,
"int",
"int",
"str",
"List[bool]",
]
assert [a.as_string() if a else None for a in init.args.defaults] == [
"10",
"'hi'",
"_HAS_DEFAULT_FACTORY",
]
@parametrize_module
def test_init_initvar(module: str):
"""Test init for a dataclass with attributes and an InitVar"""
node = astroid.extract_node(
f"""
from {module} import dataclass
from dataclasses import InitVar
from typing import List
@dataclass
class A:
x: int
y: str
init_var: InitVar[int]
z: List[bool]
A.__init__ #@
"""
)
init = next(node.infer())
assert [a.name for a in init.args.args] == ["self", "x", "y", "init_var", "z"]
assert [a.as_string() if a else None for a in init.args.annotations] == [
None,
"int",
"str",
"int",
"List[bool]",
]
@parametrize_module
def test_init_decorator_init_false(module: str):
"""Test that no init is generated when init=False is passed to
dataclass decorator.
"""
node = astroid.extract_node(
f"""
from {module} import dataclass
from typing import List
@dataclass(init=False)
class A:
x: int
y: str
z: List[bool]
A.__init__ #@
"""
)
init = next(node.infer())
assert init._proxied.parent.name == "object"
@parametrize_module
def test_init_field_init_false(module: str):
"""Test init for a dataclass with attributes with a field value where init=False
(these attributes should not be included in the initializer).
"""
node = astroid.extract_node(
f"""
from {module} import dataclass
from dataclasses import field
from typing import List
@dataclass
class A:
x: int
y: str
z: List[bool] = field(init=False)
A.__init__ #@
"""
)
init = next(node.infer())
assert [a.name for a in init.args.args] == ["self", "x", "y"]
assert [a.as_string() if a else None for a in init.args.annotations] == [
None,
"int",
"str",
]
@parametrize_module
def test_init_override(module: str):
"""Test init for a dataclass overrides a superclass initializer.
Based on https://github.com/PyCQA/pylint/issues/3201
"""
node = astroid.extract_node(
f"""
from {module} import dataclass
from typing import List
class A:
arg0: str = None
def __init__(self, arg0):
raise NotImplementedError
@dataclass
class B(A):
arg1: int = None
arg2: str = None
B.__init__ #@
"""
)
init = next(node.infer())
assert [a.name for a in init.args.args] == ["self", "arg1", "arg2"]
assert [a.as_string() if a else None for a in init.args.annotations] == [
None,
"int",
"str",
]
@parametrize_module
def test_init_attributes_from_superclasses(module: str):
"""Test init for a dataclass that inherits and overrides attributes from superclasses.
Based on https://github.com/PyCQA/pylint/issues/3201
"""
node = astroid.extract_node(
f"""
from {module} import dataclass
from typing import List
@dataclass
class A:
arg0: float
arg2: str
@dataclass
class B(A):
arg1: int
arg2: list # Overrides arg2 from A
B.__init__ #@
"""
)
init = next(node.infer())
assert [a.name for a in init.args.args] == ["self", "arg0", "arg2", "arg1"]
assert [a.as_string() if a else None for a in init.args.annotations] == [
None,
"float",
"list", # not str
"int",
]
@parametrize_module
def test_invalid_init(module: str):
"""Test that astroid doesn't generate an initializer when attribute order is invalid."""
node = astroid.extract_node(
f"""
from {module} import dataclass
@dataclass
class A:
arg1: float = 0.0
arg2: str
A.__init__ #@
"""
)
init = next(node.infer())
assert init._proxied.parent.name == "object"
@parametrize_module
def test_annotated_enclosed_field_call(module: str):
"""Test inference of dataclass attribute with a field call in another function call"""
node = astroid.extract_node(
f"""
from {module} import dataclass, field
from typing import cast
@dataclass
class A:
attribute: int = cast(int, field(default_factory=dict))
"""
)
inferred = node.inferred()
assert len(inferred) == 1 and isinstance(inferred[0], nodes.ClassDef)
assert "attribute" in inferred[0].instance_attrs
@parametrize_module
def test_invalid_field_call(module: str) -> None:
"""Test inference of invalid field call doesn't crash."""
code = astroid.extract_node(
f"""
from {module} import dataclass, field
@dataclass
class A:
val: field()
"""
)
inferred = code.inferred()
assert len(inferred) == 1
assert isinstance(inferred[0], nodes.ClassDef)