Switch from 'toml' package to tomli/tomllib

Python 3.11 comes with built-in support for TOML. It's an almost direct
import of the tomli package. As the 'toml' library is unmaintained, and
tomli has the same interface as what's in the standard library, this
switches the TOML support to a supported library with a minimum of fuss.

Tomllib requires files to be opened in 'rb' mode, so the relevant tests
had to be updated accordingly.

setup.py

@@ -29,7 +29,7 @@ def get_abs_path(pathname):
     install_requires=[
         "flake8 >= 2.0.0",
         "setuptools >= 10.0.0",
-        "toml >= 0.7.0",
+        "tomli>=1.2.1; python_version < '3.11'",
     ],
     setup_requires=["pytest-runner"],
     tests_require=["mock", "pytest"],

src/flake8_requirements/checker.py

@@ -9,16 +9,20 @@
 from logging import getLogger
 
 import flake8
-import toml
 from pkg_resources import parse_requirements
 from pkg_resources import yield_lines
 
+if sys.version_info >= (3, 11):
+    import tomllib
+else:
+    import tomli as tomllib
+
 from .modules import KNOWN_3RD_PARTIES
 from .modules import STDLIB_PY2
 from .modules import STDLIB_PY3
 
 # NOTE: Changing this number will alter package version as well.
-__version__ = "1.7.5"
+__version__ = "1.7.6"
 __license__ = "MIT"
 
 LOG = getLogger('flake8.plugin.requirements')
@@ -545,10 +549,11 @@ def resolve_requirement(cls, requirement, max_depth=0, path=None):
     @memoize
     def get_pyproject_toml(cls):
         """Try to load PEP 518 configuration file."""
+        pyproject_config_path = os.path.join(cls.root_dir, "pyproject.toml")
         try:
-            with open(os.path.join(cls.root_dir, "pyproject.toml")) as f:
-                return toml.loads(f.read())
-        except (IOError, toml.TomlDecodeError) as e:
+            with open(pyproject_config_path, mode="rb") as f:
+                return tomllib.load(f)
+        except (IOError, tomllib.TOMLDecodeError) as e:
             LOG.debug("Couldn't load project setup: %s", e)
             return {}
 

test/test_pep621.py

@@ -21,7 +21,7 @@ class Flake8Options:
 
 class Pep621TestCase(unittest.TestCase):
 
-    content = """
+    content = b"""
     [project]
     name="test"
     dependencies=["tools==1.0"]
@@ -58,7 +58,7 @@ def test_get_pyproject_toml_pep621(self):
             self.assertDictEqual(pep621, expected)
 
     def test_get_pyproject_toml_invalid(self):
-        content = self.content + "invalid"
+        content = self.content + b"invalid"
         with mock.patch(builtins_open, mock.mock_open(read_data=content)):
             self.assertDictEqual(Flake8Checker.get_pyproject_toml_pep621(), {})
 

test/test_poetry.py

@@ -18,13 +18,13 @@ def setUp(self):
         memoize.mem = {}
 
     def test_get_pyproject_toml_poetry(self):
-        content = "[tool.poetry]\nname='x'\n[tool.poetry.tag]\nx=0\n"
+        content = b"[tool.poetry]\nname='x'\n[tool.poetry.tag]\nx=0\n"
         with mock.patch(builtins_open, mock.mock_open(read_data=content)):
             poetry = Flake8Checker.get_pyproject_toml_poetry()
             self.assertDictEqual(poetry, {'name': "x", 'tag': {'x': 0}})
 
     def test_1st_party(self):
-        content = "[tool.poetry]\nname='book'\n"
+        content = b"[tool.poetry]\nname='book'\n"
 
         with mock.patch(builtins_open, mock.mock_open()) as m:
             m.side_effect = (
@@ -38,8 +38,8 @@ def test_1st_party(self):
             self.assertEqual(mods, ModuleSet({"book": {}}))
 
     def test_3rd_party(self):
-        content = "[tool.poetry.dependencies]\ntools='1.0'\n"
-        content += "[tool.poetry.dev-dependencies]\ndev-tools='1.0'\n"
+        content = b"[tool.poetry.dependencies]\ntools='1.0'\n"
+        content += b"[tool.poetry.dev-dependencies]\ndev-tools='1.0'\n"
 
         with mock.patch(builtins_open, mock.mock_open()) as m:
             m.side_effect = (
@@ -53,8 +53,8 @@ def test_3rd_party(self):
             self.assertEqual(mods, ModuleSet({"tools": {}, "dev_tools": {}}))
 
     def test_3rd_party_groups(self):
-        content = "[tool.poetry.dependencies]\ntools='1.0'\n"
-        content += "[tool.poetry.group.dev.dependencies]\ndev-tools='1.0'\n"
+        content = b"[tool.poetry.dependencies]\ntools='1.0'\n"
+        content += b"[tool.poetry.group.dev.dependencies]\ndev-tools='1.0'\n"
 
         with mock.patch(builtins_open, mock.mock_open()) as m:
             m.side_effect = (