name : checker_test_case.py # 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 import contextlib import warnings from collections.abc import Generator, Iterator from typing import Any from astroid import nodes from pylint.constants import IS_PYPY, PY38_PLUS, PY39_PLUS from pylint.testutils.global_test_linter import linter from pylint.testutils.output_line import MessageTest from pylint.testutils.unittest_linter import UnittestLinter from pylint.utils import ASTWalker class CheckerTestCase: """A base testcase class for unit testing individual checker classes.""" # TODO: Figure out way to type this as type[BaseChecker] while also # setting self.checker correctly. CHECKER_CLASS: Any CONFIG: dict[str, Any] = {} def setup_method(self) -> None: self.linter = UnittestLinter() self.checker = self.CHECKER_CLASS(self.linter) for key, value in self.CONFIG.items(): setattr(self.checker.linter.config, key, value) self.checker.open() @contextlib.contextmanager def assertNoMessages(self) -> Iterator[None]: """Assert that no messages are added by the given method.""" with self.assertAddsMessages(): yield @contextlib.contextmanager def assertAddsMessages( self, *messages: MessageTest, ignore_position: bool = False ) -> Generator[None, None, None]: """Assert that exactly the given method adds the given messages. The list of messages must exactly match *all* the messages added by the method. Additionally, we check to see whether the args in each message can actually be substituted into the message string. Using the keyword argument `ignore_position`, all checks for position arguments (line, col_offset, ...) will be skipped. This can be used to just test messages for the correct node. """ yield got = self.linter.release_messages() no_msg = "No message." expected = "\n".join(repr(m) for m in messages) or no_msg got_str = "\n".join(repr(m) for m in got) or no_msg msg = ( "Expected messages did not match actual.\n" f"\nExpected:\n{expected}\n\nGot:\n{got_str}\n" ) assert len(messages) == len(got), msg for expected_msg, gotten_msg in zip(messages, got): assert expected_msg.msg_id == gotten_msg.msg_id, msg assert expected_msg.node == gotten_msg.node, msg assert expected_msg.args == gotten_msg.args, msg assert expected_msg.confidence == gotten_msg.confidence, msg if ignore_position: # Do not check for line, col_offset etc... continue assert expected_msg.line == gotten_msg.line, msg assert expected_msg.col_offset == gotten_msg.col_offset, msg if PY38_PLUS and not IS_PYPY or PY39_PLUS: # TODO: 3.0: Remove deprecated missing arguments and remove the warning if not expected_msg.end_line == gotten_msg.end_line: warnings.warn( # pragma: no cover f"The end_line attribute of {gotten_msg} does not match " f"the expected value in {expected_msg}. In pylint 3.0 correct end_line " "attributes will be required for MessageTest.", DeprecationWarning, stacklevel=2, ) if not expected_msg.end_col_offset == gotten_msg.end_col_offset: warnings.warn( # pragma: no cover f"The end_col_offset attribute of {gotten_msg} does not match " f"the expected value in {expected_msg}. In pylint 3.0 correct end_col_offset " "attributes will be required for MessageTest.", DeprecationWarning, stacklevel=2, ) def walk(self, node: nodes.NodeNG) -> None: """Recursive walk on the given node.""" walker = ASTWalker(linter) walker.add_checker(self.checker) walker.walk(node)