Use tomllib/tomli for reading .toml configs (#608)

Use the built-in `tomllib` module in Python 3.11 and the modern `tomli`
package in older Python versions to read .toml configs instead of
the unmaintained and broken `toml` package.

Fixes #599
Fixes #600

Co-authored-by: Sambhav Kothari <sambhavs.email@gmail.com>

docs/release_notes.rst

@@ -5,6 +5,13 @@ Release Notes
 `Semantic Versioning <http://semver.org/>`_ specification.
 
 
+Current Development Version
+---------------------------
+
+Bug Fixes
+
+* Use tomllib/tomli to correctly read .toml files (#599, #600).
+
 6.2.0 - January 2nd, 2023
 ---------------------------
 

pyproject.toml

@@ -21,11 +21,11 @@ classifiers = [
 [tool.poetry.dependencies]
 python = ">=3.6"
 snowballstemmer = ">=2.2.0"
-toml = {version = ">=0.10.2", optional = true}
+tomli = {version = ">=1.2.3", optional = true, python = "<3.11"}
 importlib-metadata = {version = ">=2.0.0,<5.0.0", python = "<3.8"}
 
 [tool.poetry.extras]
-toml = ["toml"]
+toml = ["tomli"]
 
 [tool.poetry.scripts]
 pydocstyle = "pydocstyle.cli:main"

requirements/runtime.txt

@@ -1,3 +1,3 @@
 snowballstemmer>=1.2.1
-toml>=0.10.2
+tomli>=1.2.3; python_version < "3.11"
 importlib-metadata<5.0.0,>=2.0.0; python_version < "3.8"

requirements/tests.txt

@@ -2,5 +2,4 @@ pytest==6.2.5
 mypy==0.930
 black==22.3
 isort==5.4.2
-types-toml
 types-setuptools

src/pydocstyle/config.py

@@ -4,6 +4,7 @@
 import itertools
 import operator
 import os
+import sys
 from collections import namedtuple
 from collections.abc import Set
 from configparser import NoOptionError, NoSectionError, RawConfigParser
@@ -14,10 +15,13 @@
 from .utils import log
 from .violations import ErrorRegistry, conventions
 
-try:
-    import toml
-except ImportError:  # pragma: no cover
-    toml = None  # type: ignore
+if sys.version_info >= (3, 11):
+    import tomllib
+else:
+    try:
+        import tomli as tomllib
+    except ImportError:  # pragma: no cover
+        tomllib = None  # type: ignore
 
 
 def check_initialized(method):
@@ -60,15 +64,15 @@ def read(self, filenames, encoding=None):
         read_ok = []
         for filename in filenames:
             try:
-                with open(filename, encoding=encoding) as fp:
-                    if not toml:
+                with open(filename, "rb") as fp:
+                    if not tomllib:
                         log.warning(
                             "The %s configuration file was ignored, "
-                            "because the `toml` package is not installed.",
+                            "because the `tomli` package is not installed.",
                             filename,
                         )
                         continue
-                    self._config.update(toml.load(fp))
+                    self._config.update(tomllib.load(fp))
             except OSError:
                 continue
             if isinstance(filename, os.PathLike):