doc/whatsnew/2/2.15/index.rst

***************************
 What's New in Pylint 2.15
***************************

.. toctree::
   :maxdepth: 2

:Release: 2.15
:Date: 2022-08-26

Summary -- Release highlights
=============================

In pylint 2.15.0, we added a new check ``missing-timeout`` to warn of
default timeout values that could cause a program to be hanging indefinitely.

We improved ``pylint``'s handling of namespace packages. More packages should
be linted without resorting to using the ``--recursive=y`` option.

We still welcome any community effort to help review, integrate, and add good/bad examples to the doc for
<https://github.com/PyCQA/pylint/issues/5953>`_. This should be doable without any ``pylint`` or ``astroid``
knowledge, so this is the perfect entrypoint if you want to contribute to ``pylint`` or open source without
any experience with our code!

Internally, we changed the way we generate the release notes, thanks to DudeNr33.
There will be no more conflict resolution to do in the changelog, and every contributor rejoice.

Marc Byrne became a maintainer, welcome to the team !

.. towncrier release notes start

What's new in Pylint 2.15.7?
----------------------------
Release date: 2022-11-27


False Positives Fixed
---------------------

- Fix ``deprecated-method`` false positive when alias for method is similar to
  name of deprecated method.

  Closes #5886 (`#5886 <https://github.com/PyCQA/pylint/issues/5886>`_)

- Fix a false positive for ``used-before-assignment`` for imports guarded by
  ``typing.TYPE_CHECKING`` later used in variable annotations.

  Closes #7609 (`#7609 <https://github.com/PyCQA/pylint/issues/7609>`_)



Other Bug Fixes
---------------

- Pylint will now filter duplicates given to it before linting. The output
  should
  be the same whether a file is given/discovered multiple times or not.

  Closes #6242, #4053 (`#6242 <https://github.com/PyCQA/pylint/issues/6242>`_)

- Fixes a crash in ``stop-iteration-return`` when the ``next`` builtin is
  called without arguments.

  Closes #7828 (`#7828 <https://github.com/PyCQA/pylint/issues/7828>`_)


What's new in Pylint 2.15.6?
----------------------------
Release date: 2022-11-19


False Positives Fixed
---------------------

- Fix false positive for ``unhashable-member`` when subclassing ``dict`` and
  using the subclass as a dictionary key.

  Closes #7501 (`#7501 <https://github.com/PyCQA/pylint/issues/7501>`_)

- ``unnecessary-list-index-lookup`` will not be wrongly emitted if
  ``enumerate`` is called with ``start``.

  Closes #7682 (`#7682 <https://github.com/PyCQA/pylint/issues/7682>`_)

- Don't warn about ``stop-iteration-return`` when using ``next()`` over
  ``itertools.cycle``.

  Closes #7765 (`#7765 <https://github.com/PyCQA/pylint/issues/7765>`_)



Other Bug Fixes
---------------

- Messages sent to reporter are now copied so a reporter cannot modify the
  message sent to other reporters.

  Closes #7214 (`#7214 <https://github.com/PyCQA/pylint/issues/7214>`_)

- Fixes edge case of custom method named ``next`` raised an astroid error.

  Closes #7610 (`#7610 <https://github.com/PyCQA/pylint/issues/7610>`_)

- Fix crash that happened when parsing files with unexpected encoding starting
  with 'utf' like ``utf13``.

  Closes #7661 (`#7661 <https://github.com/PyCQA/pylint/issues/7661>`_)

- Fix a crash when a child class with an ``__init__`` method inherits from a
  parent class with an ``__init__`` class attribute.

  Closes #7742 (`#7742 <https://github.com/PyCQA/pylint/issues/7742>`_)


What's new in Pylint 2.15.5?
----------------------------
Release date: 2022-10-21


False Positives Fixed
---------------------

- Fix a false positive for ``simplify-boolean-expression`` when multiple values
  are inferred for a constant.

  Closes #7626 (`#7626 <https://github.com/PyCQA/pylint/issues/7626>`_)



Other Bug Fixes
---------------

- Remove ``__index__`` dunder method call from ``unnecessary-dunder-call``
  check.

  Closes #6795 (`#6795 <https://github.com/PyCQA/pylint/issues/6795>`_)

- Fixed a multi-processing crash that prevents using any more than 1 thread on
  MacOS.

  The returned module objects and errors that were cached by the linter plugin
  loader
  cannot be reliably pickled. This means that ``dill`` would throw an error
  when
  attempting to serialise the linter object for multi-processing use.

  Closes #7635. (`#7635 <https://github.com/PyCQA/pylint/issues/7635>`_)



Other Changes
-------------

- Add a keyword-only ``compare_constants`` argument to ``safe_infer``.

  Refs #7626 (`#7626 <https://github.com/PyCQA/pylint/issues/7626>`_)

- Sort ``--generated-rcfile`` output.

  Refs #7655 (`#7655 <https://github.com/PyCQA/pylint/issues/7655>`_)


What's new in Pylint 2.15.4?
----------------------------
Release date: 2022-10-10


False Positives Fixed
---------------------

- Fix the message for ``unnecessary-dunder-call`` for ``__aiter__`` and
  ``__aneext__``. Also
  only emit the warning when ``py-version`` >= 3.10.

  Closes #7529 (`#7529 <https://github.com/PyCQA/pylint/issues/7529>`_)



Other Bug Fixes
---------------

- Fix bug in detecting ``unused-variable`` when iterating on variable.

  Closes #3044 (`#3044 <https://github.com/PyCQA/pylint/issues/3044>`_)

- Fixed handling of ``--`` as separator between positional arguments and flags.
  This was not actually fixed in 2.14.5.

  Closes #7003, Refs #7096 (`#7003
  <https://github.com/PyCQA/pylint/issues/7003>`_)

- Report ``no-self-argument`` rather than ``no-method-argument`` for methods
  with variadic arguments.

  Closes #7507 (`#7507 <https://github.com/PyCQA/pylint/issues/7507>`_)

- Fixed an issue where ``syntax-error`` couldn't be raised on files with
  invalid encodings.

  Closes #7522 (`#7522 <https://github.com/PyCQA/pylint/issues/7522>`_)

- Fix false positive for ``redefined-outer-name`` when aliasing ``typing``
  e.g. as ``t`` and guarding imports under ``t.TYPE_CHECKING``.

  Closes #7524 (`#7524 <https://github.com/PyCQA/pylint/issues/7524>`_)

- Fixed a crash of the ``modified_iterating`` checker when iterating on a set
  defined as a class attribute.

  Closes #7528 (`#7528 <https://github.com/PyCQA/pylint/issues/7528>`_)

- Fix bug in scanning of names inside arguments to `typing.Literal`.
  See https://peps.python.org/pep-0586/#literals-enums-and-forward-references
  for details.

  Refs #3299 (`#3299 <https://github.com/PyCQA/pylint/issues/3299>`_)


Other Changes
-------------

- Add method name to the error messages of ``no-method-argument`` and
  ``no-self-argument``.

  Closes #7507 (`#7507 <https://github.com/PyCQA/pylint/issues/7507>`_)


What's new in Pylint 2.15.3?
----------------------------
Release date: 2022-09-19


- Fixed a crash in the ``unhashable-member`` checker when using a ``lambda`` as a dict key.

  Closes #7453 (`#7453 <https://github.com/PyCQA/pylint/issues/7453>`_)
- Fix a crash in the ``modified-iterating-dict`` checker involving instance attributes.

  Closes #7461 (`#7461 <https://github.com/PyCQA/pylint/issues/7461>`_)
- ``invalid-class-object`` does not crash anymore when ``__class__`` is assigned alongside another variable.

  Closes #7467 (`#7467 <https://github.com/PyCQA/pylint/issues/7467>`_)
- Fix false positive for ``global-variable-not-assigned`` when a global variable is re-assigned via an ``ImportFrom`` node.

  Closes #4809 (`#4809 <https://github.com/PyCQA/pylint/issues/4809>`_)
- Fix false positive for ``undefined-loop-variable`` in ``for-else`` loops that use a function
  having a return type annotation of ``NoReturn`` or ``Never``.

  Closes #7311 (`#7311 <https://github.com/PyCQA/pylint/issues/7311>`_)
- ``--help-msg`` now accepts a comma-separated list of message IDs again.

  Closes #7471 (`#7471 <https://github.com/PyCQA/pylint/issues/7471>`_)

What's new in Pylint 2.15.2?
----------------------------
Release date: 2022-09-07

- Fixed a case where custom plugins specified by command line could silently fail.

  Specifically, if a plugin relies on the ``init-hook`` option changing ``sys.path`` before
  it can be imported, this will now emit a ``bad-plugin-value`` message. Before this
  change, it would silently fail to register the plugin for use, but would load
  any configuration, which could have unintended effects.

  Fixes part of #7264. (`#7264 <https://github.com/PyCQA/pylint/issues/7264>`_)
- Fix ``used-before-assignment`` for functions/classes defined in type checking guard.

  Closes #7368 (`#7368 <https://github.com/PyCQA/pylint/issues/7368>`_)
- Update ``modified_iterating`` checker to fix a crash with ``for`` loops on empty list.

  Closes #7380 (`#7380 <https://github.com/PyCQA/pylint/issues/7380>`_)
- The ``docparams`` extension now considers typing in Numpy style docstrings
  as "documentation" for the ``missing-param-doc`` message.

  Refs #7398 (`#7398 <https://github.com/PyCQA/pylint/issues/7398>`_)
- Fix false positive for ``unused-variable`` and ``unused-import`` when a name is only used in a string literal type annotation.

  Closes #3299 (`#3299 <https://github.com/PyCQA/pylint/issues/3299>`_)
- Fix false positive for ``too-many-function-args`` when a function call is assigned to a class attribute inside the class where the function is defined.

  Closes #6592 (`#6592 <https://github.com/PyCQA/pylint/issues/6592>`_)
- Fix ``used-before-assignment`` for functions/classes defined in type checking guard.

  Closes #7368 (`#7368 <https://github.com/PyCQA/pylint/issues/7368>`_)
- Fix ignored files being linted when passed on stdin.

  Closes #4354 (`#4354 <https://github.com/PyCQA/pylint/issues/4354>`_)
- ``missing-return-doc``, ``missing-raises-doc`` and ``missing-yields-doc`` now respect
  the ``no-docstring-rgx`` option.

  Closes #4743 (`#4743 <https://github.com/PyCQA/pylint/issues/4743>`_)
- Don't crash on ``OSError`` in config file discovery.

  Closes #7169 (`#7169 <https://github.com/PyCQA/pylint/issues/7169>`_)
- ``disable-next`` is now correctly scoped to only the succeeding line.

  Closes #7401 (`#7401 <https://github.com/PyCQA/pylint/issues/7401>`_)
- Update ``modified_iterating`` checker to fix a crash with ``for`` loops on empty list.

  Closes #7380 (`#7380 <https://github.com/PyCQA/pylint/issues/7380>`_)

What's new in Pylint 2.15.1?
----------------------------
Release date: 2022-09-06

This is a "github only release", it was mistakenly released as ``2.16.0-dev`` on pypi. Replaced by ``2.15.2``.

What's new in Pylint 2.15.0?
----------------------------

New Checks
----------

- Added new checker ``missing-timeout`` to warn of default timeout values that could cause
  a program to be hanging indefinitely.

  Refs #6780 (`#6780 <https://github.com/PyCQA/pylint/issues/6780>`_)


False Positives Fixed
---------------------

- Don't report ``super-init-not-called`` for abstract ``__init__`` methods.

  Closes #3975 (`#3975 <https://github.com/PyCQA/pylint/issues/3975>`_)
- Don't report ``unsupported-binary-operation`` on Python <= 3.9 when using the ``|`` operator
  with types, if one has a metaclass that overloads ``__or__`` or ``__ror__`` as appropriate.

  Closes #4951 (`#4951 <https://github.com/PyCQA/pylint/issues/4951>`_)
- Don't report ``no-value-for-parameter`` for dataclasses fields annotated with ``KW_ONLY``.

  Closes #5767 (`#5767 <https://github.com/PyCQA/pylint/issues/5767>`_)
- Fixed inference of ``Enums`` when they are imported under an alias.

  Closes #5776 (`#5776 <https://github.com/PyCQA/pylint/issues/5776>`_)
- Prevent false positives when accessing ``PurePath.parents`` by index (not slice) on Python 3.10+.

  Closes #5832 (`#5832 <https://github.com/PyCQA/pylint/issues/5832>`_)
- ``unnecessary-list-index-lookup`` is now more conservative to avoid potential false positives.

  Closes #6896 (`#6896 <https://github.com/PyCQA/pylint/issues/6896>`_)
- Fix double emitting ``trailing-whitespace`` for multi-line docstrings.

  Closes #6936 (`#6936 <https://github.com/PyCQA/pylint/issues/6936>`_)
- ``import-error`` now correctly checks for ``contextlib.suppress`` guards on import statements.

  Closes #7270 (`#7270 <https://github.com/PyCQA/pylint/issues/7270>`_)
- Fix false positive for `no-self-argument`/`no-method-argument` when a staticmethod is applied to a function but uses a different name.

  Closes #7300 (`#7300 <https://github.com/PyCQA/pylint/issues/7300>`_)
- Fix `undefined-loop-variable` with `break` and `continue` statements in `else` blocks.

  Refs #7311 (`#7311 <https://github.com/PyCQA/pylint/issues/7311>`_)
- Improve default TypeVar name regex. Disallow names prefixed with ``T``.
  E.g. use ``AnyStrT`` instead of ``TAnyStr``.

  Refs #7322 (`#7322 <https://github.com/PyCQA/pylint/issues/7322>`_`)


False Negatives Fixed
---------------------

- Emit ``used-before-assignment`` when relying on a name that is reimported later in a function.

  Closes #4624 (`#4624 <https://github.com/PyCQA/pylint/issues/4624>`_)
- Emit ``used-before-assignment`` for self-referencing named expressions (``:=``) lacking
  prior assignments.

  Closes #5653 (`#5653 <https://github.com/PyCQA/pylint/issues/5653>`_)
- Emit ``used-before-assignment`` for self-referencing assignments under if conditions.

  Closes #6643 (`#6643 <https://github.com/PyCQA/pylint/issues/6643>`_)
- Emit ``modified-iterating-list`` and analogous messages for dicts and sets when iterating
  literals, or when using the ``del`` keyword.

  Closes #6648 (`#6648 <https://github.com/PyCQA/pylint/issues/6648>`_)
- Emit ``used-before-assignment`` when calling nested functions before assignment.

  Closes #6812 (`#6812 <https://github.com/PyCQA/pylint/issues/6812>`_)
- Emit ``nonlocal-without-binding`` when a nonlocal name has been assigned at a later point in the same scope.

  Closes #6883 (`#6883 <https://github.com/PyCQA/pylint/issues/6883>`_)
- Emit ``using-constant-test`` when testing the truth value of a variable or call result
  holding a generator.

  Closes #6909 (`#6909 <https://github.com/PyCQA/pylint/issues/6909>`_)
- Rename ``unhashable-dict-key`` to ``unhashable-member`` and emit when creating sets and dicts,
  not just when accessing dicts.

  Closes #7034, Closes #7055 (`#7034 <https://github.com/PyCQA/pylint/issues/7034>`_)


Other Bug Fixes
---------------

- Fix a failure to lint packages with ``__init__.py`` contained in directories lacking ``__init__.py``.

  Closes #1667 (`#1667 <https://github.com/PyCQA/pylint/issues/1667>`_)
- Fixed a syntax-error crash that was not handled properly when the declared encoding of a file
  was ``utf-9``.

  Closes #3860 (`#3860 <https://github.com/PyCQA/pylint/issues/3860>`_)
- Fix a crash in the ``not-callable`` check when there is ambiguity whether an instance is being incorrectly provided to ``__new__()``.

  Closes #7109 (`#7109 <https://github.com/PyCQA/pylint/issues/7109>`_)
- Fix crash when regex option raises a `re.error` exception.

  Closes #7202 (`#7202 <https://github.com/PyCQA/pylint/issues/7202>`_)
- Fix `undefined-loop-variable` from walrus in comprehension test.

  Closes #7222 (`#7222 <https://github.com/PyCQA/pylint/issues/7222>`_)
- Check for `<cwd>` before removing first item from `sys.path` in `modify_sys_path`.

  Closes #7231 (`#7231 <https://github.com/PyCQA/pylint/issues/7231>`_)
- Fix sys.path pollution in parallel mode.

  Closes #7246 (`#7246 <https://github.com/PyCQA/pylint/issues/7246>`_)
- Prevent `useless-parent-delegation` for delegating to a builtin
  written in C (e.g. `Exception.__init__`) with non-self arguments.

  Closes #7319 (`#7319 <https://github.com/PyCQA/pylint/issues/7319>`_)


Other Changes
-------------

- ``bad-exception-context`` has been renamed to ``bad-exception-cause`` as it is about the cause and not the context.

  Closes #3694 (`#3694 <https://github.com/PyCQA/pylint/issues/3694>`_)
- The message for ``literal-comparison`` is now more explicit about the problem and the
  solution.

  Closes #5237 (`#5237 <https://github.com/PyCQA/pylint/issues/5237>`_)
- ``useless-super-delegation`` has been renamed to ``useless-parent-delegation`` in order to be more generic.

  Closes #6953 (`#6953 <https://github.com/PyCQA/pylint/issues/6953>`_)
- Pylint now uses ``towncrier`` for changelog generation.

  Refs #6974 (`#6974 <https://github.com/PyCQA/pylint/issues/6974>`_)
- Update ``astroid`` to 2.12.

  Refs #7153 (`#7153 <https://github.com/PyCQA/pylint/issues/7153>`_)
- Fix crash when a type-annotated `__slots__` with no value is declared.

  Closes #7280 (`#7280 <https://github.com/PyCQA/pylint/issues/7280>`_)


Internal Changes
----------------

- Fixed an issue where it was impossible to update functional tests output when the existing
  output was impossible to parse. Instead of raising an error we raise a warning message and
  let the functional test fail with a default value.

  Refs #6891 (`#6891 <https://github.com/PyCQA/pylint/issues/6891>`_)
- ``pylint.testutils.primer`` is now a private API.

  Refs #6905 (`#6905 <https://github.com/PyCQA/pylint/issues/6905>`_)
- We changed the way we handle the changelog internally by using towncrier.
  If you're a contributor you won't have to fix merge conflicts in the
  changelog anymore.

  Closes #6974 (`#6974 <https://github.com/PyCQA/pylint/issues/6974>`_)
- Pylint is now using Scorecards to implement security recommendations from the
  `OpenSSF <https://openssf.org/>`_. This is done in order to secure our supply chains using a combination
  of automated tooling and best practices, most of which were already implemented before.

  Refs #7267 (`#7267 <https://github.com/PyCQA/pylint/issues/7267>`_)