| # Licensed under the LGPL: https://www.gnu.org/licenses/old-licenses/lgpl-2.1.en.html |
| # For details: https://github.com/pylint-dev/astroid/blob/main/LICENSE |
| # Copyright (c) https://github.com/pylint-dev/astroid/blob/main/CONTRIBUTORS.txt |
| |
| """ |
| Astroid hook for the attrs library |
| |
| Without this hook pylint reports unsupported-assignment-operation |
| for attrs classes |
| """ |
| from astroid.manager import AstroidManager |
| from astroid.nodes.node_classes import AnnAssign, Assign, AssignName, Call, Unknown |
| from astroid.nodes.scoped_nodes import ClassDef |
| from astroid.util import safe_infer |
| |
| ATTRIB_NAMES = frozenset( |
| ( |
| "attr.Factory", |
| "attr.ib", |
| "attrib", |
| "attr.attrib", |
| "attr.field", |
| "attrs.field", |
| "field", |
| ) |
| ) |
| ATTRS_NAMES = frozenset( |
| ( |
| "attr.s", |
| "attrs", |
| "attr.attrs", |
| "attr.attributes", |
| "attr.define", |
| "attr.mutable", |
| "attr.frozen", |
| "attrs.define", |
| "attrs.mutable", |
| "attrs.frozen", |
| ) |
| ) |
| |
| |
| def is_decorated_with_attrs(node, decorator_names=ATTRS_NAMES) -> bool: |
| """Return whether a decorated node has an attr decorator applied.""" |
| if not node.decorators: |
| return False |
| for decorator_attribute in node.decorators.nodes: |
| if isinstance(decorator_attribute, Call): # decorator with arguments |
| decorator_attribute = decorator_attribute.func |
| if decorator_attribute.as_string() in decorator_names: |
| return True |
| |
| inferred = safe_infer(decorator_attribute) |
| if inferred and inferred.root().name == "attr._next_gen": |
| return True |
| return False |
| |
| |
| def attr_attributes_transform(node: ClassDef) -> None: |
| """Given that the ClassNode has an attr decorator, |
| rewrite class attributes as instance attributes |
| """ |
| # Astroid can't infer this attribute properly |
| # Prevents https://github.com/pylint-dev/pylint/issues/1884 |
| node.locals["__attrs_attrs__"] = [Unknown(parent=node)] |
| |
| for cdef_body_node in node.body: |
| if not isinstance(cdef_body_node, (Assign, AnnAssign)): |
| continue |
| if isinstance(cdef_body_node.value, Call): |
| if cdef_body_node.value.func.as_string() not in ATTRIB_NAMES: |
| continue |
| else: |
| continue |
| targets = ( |
| cdef_body_node.targets |
| if hasattr(cdef_body_node, "targets") |
| else [cdef_body_node.target] |
| ) |
| for target in targets: |
| rhs_node = Unknown( |
| lineno=cdef_body_node.lineno, |
| col_offset=cdef_body_node.col_offset, |
| parent=cdef_body_node, |
| ) |
| if isinstance(target, AssignName): |
| # Could be a subscript if the code analysed is |
| # i = Optional[str] = "" |
| # See https://github.com/pylint-dev/pylint/issues/4439 |
| node.locals[target.name] = [rhs_node] |
| node.instance_attrs[target.name] = [rhs_node] |
| |
| |
| def register(manager: AstroidManager) -> None: |
| manager.register_transform( |
| ClassDef, attr_attributes_transform, is_decorated_with_attrs |
| ) |