# Licensed under the GPL: https://www.gnu.org/licenses/old-licenses/gpl-2.0.html # For details: https://github.com/PyCQA/pylint/blob/main/LICENSE # Copyright (c) https://github.com/PyCQA/pylint/blob/main/CONTRIBUTORS.txt from __future__ import annotations from typing import TYPE_CHECKING from astroid import nodes from pylint.checkers import BaseChecker from pylint.constants import DUNDER_METHODS, DUNDER_PROPERTIES, EXTRA_DUNDER_METHODS from pylint.interfaces import HIGH if TYPE_CHECKING: from pylint.lint import PyLinter class DunderChecker(BaseChecker): """Checks related to dunder methods.""" name = "dunder" priority = -1 msgs = { "W3201": ( "Bad or misspelled dunder method name %s.", "bad-dunder-name", "Used when a dunder method is misspelled or defined with a name " "not within the predefined list of dunder names.", ), } options = ( ( "good-dunder-names", { "default": [], "type": "csv", "metavar": "<comma-separated names>", "help": "Good dunder names which should always be accepted.", }, ), ) def open(self) -> None: self._dunder_methods = ( EXTRA_DUNDER_METHODS + DUNDER_PROPERTIES + self.linter.config.good_dunder_names ) for since_vers, dunder_methods in DUNDER_METHODS.items(): if since_vers <= self.linter.config.py_version: self._dunder_methods.extend(list(dunder_methods.keys())) def visit_functiondef(self, node: nodes.FunctionDef) -> None: """Check if known dunder method is misspelled or dunder name is not one of the pre-defined names. """ # ignore module-level functions if not node.is_method(): return # Detect something that could be a bad dunder method if ( node.name.startswith("_") and node.name.endswith("_") and node.name not in self._dunder_methods ): self.add_message( "bad-dunder-name", node=node, args=(node.name), confidence=HIGH, ) def register(linter: PyLinter) -> None: linter.register_checker(DunderChecker(linter))