# 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.checkers.utils import only_required_for_messages
if TYPE_CHECKING:
from pylint.lint import PyLinter
class ConfusingConsecutiveElifChecker(BaseChecker):
"""Checks if "elif" is used right after an indented block that finishes with "if" or
"elif" itself.
"""
name = "confusing_elif"
msgs = {
"R5601": (
"Consecutive elif with differing indentation level, consider creating a function to separate the inner"
" elif",
"confusing-consecutive-elif",
"Used when an elif statement follows right after an indented block which itself ends with if or elif. "
"It may not be ovious if the elif statement was willingly or mistakenly unindented. "
"Extracting the indented if statement into a separate function might avoid confusion and prevent "
"errors.",
)
}
@only_required_for_messages("confusing-consecutive-elif")
def visit_if(self, node: nodes.If) -> None:
body_ends_with_if = isinstance(
node.body[-1], nodes.If
) and self._has_no_else_clause(node.body[-1])
if node.has_elif_block() and body_ends_with_if:
self.add_message("confusing-consecutive-elif", node=node.orelse[0])
@staticmethod
def _has_no_else_clause(node: nodes.If) -> bool:
orelse = node.orelse
while orelse and isinstance(orelse[0], nodes.If):
orelse = orelse[0].orelse
if not orelse or isinstance(orelse[0], nodes.If):
return True
return False
def register(linter: PyLinter) -> None:
linter.register_checker(ConfusingConsecutiveElifChecker(linter))
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