# 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 """Variables checkers for Python code.""" from __future__ import annotations from typing import TYPE_CHECKING import astroid from astroid import arguments, bases, nodes from pylint.checkers import BaseChecker, utils from pylint.interfaces import INFERENCE if TYPE_CHECKING: from pylint.lint import PyLinter class MethodArgsChecker(BaseChecker): """BaseChecker for method_args. Checks for * missing-timeout * positional-only-arguments-expected """ name = "method_args" msgs = { "W3101": ( "Missing timeout argument for method '%s' can cause your program to hang indefinitely", "missing-timeout", "Used when a method needs a 'timeout' parameter in order to avoid waiting " "for a long time. If no timeout is specified explicitly the default value " "is used. For example for 'requests' the program will never time out " "(i.e. hang indefinitely).", ), "E3102": ( "`%s()` got some positional-only arguments passed as keyword arguments: %s", "positional-only-arguments-expected", "Emitted when positional-only arguments have been passed as keyword arguments. " "Remove the keywords for the affected arguments in the function call.", {"minversion": (3, 8)}, ), } options = ( ( "timeout-methods", { "default": ( "requests.api.delete", "requests.api.get", "requests.api.head", "requests.api.options", "requests.api.patch", "requests.api.post", "requests.api.put", "requests.api.request", ), "type": "csv", "metavar": "", "help": "List of qualified names (i.e., library.method) which require a timeout parameter " "e.g. 'requests.api.get,requests.api.post'", }, ), ) @utils.only_required_for_messages( "missing-timeout", "positional-only-arguments-expected" ) def visit_call(self, node: nodes.Call) -> None: self._check_missing_timeout(node) self._check_positional_only_arguments_expected(node) def _check_missing_timeout(self, node: nodes.Call) -> None: """Check if the call needs a timeout parameter based on package.func_name configured in config.timeout_methods. Package uses inferred node in order to know the package imported. """ inferred = utils.safe_infer(node.func) call_site = arguments.CallSite.from_call(node) if ( inferred and not call_site.has_invalid_keywords() and isinstance( inferred, (nodes.FunctionDef, nodes.ClassDef, bases.UnboundMethod) ) and inferred.qname() in self.linter.config.timeout_methods ): keyword_arguments = [keyword.arg for keyword in node.keywords] keyword_arguments.extend(call_site.keyword_arguments) if "timeout" not in keyword_arguments: self.add_message( "missing-timeout", node=node, args=(node.func.as_string(),), confidence=INFERENCE, ) def _check_positional_only_arguments_expected(self, node: nodes.Call) -> None: """Check if positional only arguments have been passed as keyword arguments by inspecting its method definition. """ inferred_func = utils.safe_infer(node.func) while isinstance(inferred_func, (astroid.BoundMethod, astroid.UnboundMethod)): inferred_func = inferred_func._proxied if not ( isinstance(inferred_func, (nodes.FunctionDef)) and inferred_func.args.posonlyargs ): return if inferred_func.args.kwarg: return pos_args = [a.name for a in inferred_func.args.posonlyargs] kws = [k.arg for k in node.keywords if k.arg in pos_args] if not kws: return self.add_message( "positional-only-arguments-expected", node=node, args=(node.func.as_string(), ", ".join(f"'{k}'" for k in kws)), confidence=INFERENCE, ) def register(linter: PyLinter) -> None: linter.register_checker(MethodArgsChecker(linter))