**************************
 What's New in Pylint 2.5
**************************

:Release: 2.5
:Date: TBC


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


New checkers
============

* A new check ``f-string-without-interpolation`` was added.

  This check is emitted whenever **pylint** detects the use of an
  f-string without having any interpolated values in it, which means
  that the f-string can be a normal string.

* Multiple checks for invalid return types of protocol functions were added:

   * ``invalid-bool-returned``: ``__bool__`` did not return a bool
   * ``invalid-index-returned``: ``__index__`` did not return an integer
   * ``invalid-repr-returned)``: ``__repr__`` did not return a string
   * ``invalid-str-returned)``: ``__str__`` did not return a string
   * ``invalid-bytes-returned)``: ``__bytes__`` did not return a string
   * ``invalid-hash-returned)``: ``__hash__`` did not return an integer
   * ``invalid-length-hint-returned)``: ``__length_hint__`` did not return a non-negative integer
   * ``invalid-format-returned)``: ``__format__`` did not return a string
   * ``invalid-getnewargs-returned)``: ``__getnewargs__`` did not return a tuple
   * ``invalid-getnewargs-ex-returned)``: ``__getnewargs_ex__`` did not return a tuple of the form (tuple, dict)


Other Changes
=============

* Don't emit ``line-too-long`` for multilines when a
  `pylint:disable=line-too-long` comment stands at their end.

  For example the following code will not trigger any ``line-too-long`` message::

    def example():
      """
      This is a very very very long line within a docstring that should trigger a pylint C0301 error line-too-long

      Even spread on multiple lines, the disable command is still effective on very very very, maybe too much long docstring
      """#pylint: disable=line-too-long
    pass

* Configuration can be read from a setup.cfg or pyproject.toml file
  in the current directory.
  A setup.cfg must prepend pylintrc section names with ``pylint.``,
  for example ``[pylint.MESSAGES CONTROL]``.
  A pyproject.toml file must prepend section names with ``tool.pylint.``,
  for example ``[tool.pylint.'MESSAGES CONTROL']``.
  These files can also be passed in on the command line.

* Add new good-names-rgx and bad-names-rgx to enable white-/blacklisting of regular expressions

To enable better handling of whitelisting/blacklisting names, we added two new config options: good-names-rgxs: a comma-
separated list of regexes, that if a name matches will be exempt of naming-checking. bad-names-rgxs: a comma-
separated list of regexes, that if a name matches will be always marked as a blacklisted name.

* Mutable ``collections.*`` are now flagged as dangerous defaults.

* Add new --fail-under flag for setting the threshold for the score to fail overall tests. If the score is over the fail-under threshold, pylint will complete SystemExit with value 0 to indicate no errors.