Drop Python 3.6

.github/workflows/ci.yml

@@ -12,7 +12,7 @@ jobs:
     strategy:
       matrix:
         os: [ubuntu-20.04, windows-2019]
-        python-version: ["3.6", "3.7", "3.8", "3.9", "3.10"]
+        python-version: ["3.7", "3.8", "3.9", "3.10"]
     steps:
       - uses: actions/checkout@v2
       - name: Set up Python ${{ matrix.python-version }}

.pre-commit-config.yaml

@@ -22,16 +22,17 @@ repos:
   - id: requirements-txt-fixer
   - id: trailing-whitespace
 
-- repo: https://github.com/asottile/pyupgrade
-  rev: v2.29.1
-  hooks:
-  - id: pyupgrade
-    args: [--py36-plus]
-
 - repo: https://github.com/PyCQA/isort
   rev: 5.10.1
   hooks:
   - id: isort
+    args: ["-a", "from __future__ import annotations"]
+
+- repo: https://github.com/asottile/pyupgrade
+  rev: v2.29.1
+  hooks:
+  - id: pyupgrade
+    args: [--py37-plus]
 
 - repo: https://github.com/asottile/setup-cfg-fmt
   rev: v1.20.0

docs/conf.py

@@ -11,6 +11,8 @@
 # All configuration values have a default; values that are commented out
 # serve to show the default.
 
+from __future__ import annotations
+
 import os
 import sys
 

nox/__init__.py

@@ -12,14 +12,14 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from typing import Optional
+from __future__ import annotations
 
 from nox._options import noxfile_options as options
 from nox._parametrize import Param as param
 from nox._parametrize import parametrize_decorator as parametrize
 from nox.registry import session_decorator as session
 from nox.sessions import Session
 
-needs_version: Optional[str] = None
+needs_version: str | None = None
 
 __all__ = ["needs_version", "parametrize", "param", "session", "options", "Session"]

nox/__main__.py

@@ -19,6 +19,8 @@
 control to :meth:``nox.workflow.execute``.
 """
 
+from __future__ import annotations
+
 import sys
 
 from nox import _options, tasks, workflow

nox/_decorators.py

@@ -12,11 +12,13 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+from __future__ import annotations
+
 import copy
 import functools
 import inspect
 import types
-from typing import Any, Callable, Dict, Iterable, List, Optional
+from typing import Any, Callable, Iterable
 
 from . import _typing
 
@@ -27,12 +29,12 @@
 class FunctionDecorator:
     def __new__(
         cls, func: Callable[..., Any], *args: Any, **kwargs: Any
-    ) -> "FunctionDecorator":
+    ) -> FunctionDecorator:
         obj = super().__new__(cls)
         return functools.wraps(func)(obj)
 
 
-def _copy_func(src: Callable, name: Optional[str] = None) -> Callable:
+def _copy_func(src: Callable, name: str | None = None) -> Callable:
     dst = types.FunctionType(
         src.__code__,
         src.__globals__,  # type: ignore[attr-defined]
@@ -51,11 +53,11 @@ def __init__(
         self,
         func: Callable,
         python: _typing.Python = None,
-        reuse_venv: Optional[bool] = None,
-        name: Optional[str] = None,
+        reuse_venv: bool | None = None,
+        name: str | None = None,
         venv_backend: Any = None,
         venv_params: Any = None,
-        should_warn: Optional[Dict[str, Any]] = None,
+        should_warn: dict[str, Any] | None = None,
     ):
         self.func = func
         self.python = python
@@ -67,7 +69,7 @@ def __init__(
     def __call__(self, *args: Any, **kwargs: Any) -> Any:
         return self.func(*args, **kwargs)
 
-    def copy(self, name: Optional[str] = None) -> "Func":
+    def copy(self, name: str | None = None) -> Func:
         return Func(
             _copy_func(self.func, name),
             self.python,
@@ -80,7 +82,7 @@ def copy(self, name: Optional[str] = None) -> "Func":
 
 
 class Call(Func):
-    def __init__(self, func: Func, param_spec: "Param") -> None:
+    def __init__(self, func: Func, param_spec: Param) -> None:
         call_spec = param_spec.call_spec
         session_signature = f"({param_spec})"
 
@@ -113,5 +115,5 @@ def __call__(self, *args: Any, **kwargs: Any) -> Any:
         return super().__call__(*args, **kwargs)
 
     @classmethod
-    def generate_calls(cls, func: Func, param_specs: "Iterable[Param]") -> "List[Call]":
+    def generate_calls(cls, func: Func, param_specs: Iterable[Param]) -> list[Call]:
         return [cls(func, param_spec) for param_spec in param_specs]

nox/_option_set.py

@@ -16,13 +16,14 @@
 can be specified from the command line and the noxfile, easily used in tests,
 and surfaced in documentation."""
 
+from __future__ import annotations
 
 import argparse
 import collections
 import functools
 from argparse import ArgumentError as ArgumentError
 from argparse import ArgumentParser, Namespace
-from typing import Any, Callable, List, Optional, Tuple, Union
+from typing import Any, Callable
 
 import argcomplete
 
@@ -77,14 +78,14 @@ def __init__(
         self,
         name: str,
         *flags: str,
-        group: Optional[OptionGroup],
-        help: Optional[str] = None,
+        group: OptionGroup | None,
+        help: str | None = None,
         noxfile: bool = False,
-        merge_func: Optional[Callable[[Namespace, Namespace], Any]] = None,
-        finalizer_func: Optional[Callable[[Any, Namespace], Any]] = None,
-        default: Union[Any, Callable[[], Any]] = None,
+        merge_func: Callable[[Namespace, Namespace], Any] | None = None,
+        finalizer_func: Callable[[Any, Namespace], Any] | None = None,
+        default: Any | Callable[[], Any] = None,
         hidden: bool = False,
-        completer: Optional[Callable[..., List[str]]] = None,
+        completer: Callable[..., list[str]] | None = None,
         **kwargs: Any,
     ) -> None:
         self.name = name
@@ -100,7 +101,7 @@ def __init__(
         self._default = default
 
     @property
-    def default(self) -> Optional[Union[bool, str]]:
+    def default(self) -> bool | str | None:
         if callable(self._default):
             return self._default()
         return self._default
@@ -154,10 +155,10 @@ def flag_pair_merge_func(
 
 def make_flag_pair(
     name: str,
-    enable_flags: Union[Tuple[str, str], Tuple[str]],
-    disable_flags: Tuple[str],
+    enable_flags: tuple[str, str] | tuple[str],
+    disable_flags: tuple[str],
     **kwargs: Any,
-) -> Tuple[Option, Option]:
+) -> tuple[Option, Option]:
     """Returns two options - one to enable a behavior and another to disable it.
 
     The positive option is considered to be available to the noxfile, as
@@ -191,10 +192,10 @@ class OptionSet:
     def __init__(self, *args: Any, **kwargs: Any) -> None:
         self.parser_args = args
         self.parser_kwargs = kwargs
-        self.options: "collections.OrderedDict[str, Option]" = collections.OrderedDict()
-        self.groups: "collections.OrderedDict[str, OptionGroup]" = (
-            collections.OrderedDict()
-        )
+        self.options: collections.OrderedDict[str, Option] = collections.OrderedDict()
+        self.groups: collections.OrderedDict[
+            str, OptionGroup
+        ] = collections.OrderedDict()
 
     def add_options(self, *args: Option) -> None:
         """Adds a sequence of Options to the OptionSet.

nox/_options.py

@@ -12,11 +12,13 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+from __future__ import annotations
+
 import argparse
 import functools
 import os
 import sys
-from typing import Any, List, Optional, Sequence, Union
+from typing import Any, Sequence
 
 from nox import _option_set
 from nox.tasks import discover_manifest, filter_manifest, load_nox_module
@@ -63,7 +65,7 @@
 
 def _sessions_and_keywords_merge_func(
     key: str, command_args: argparse.Namespace, noxfile_args: argparse.Namespace
-) -> List[str]:
+) -> list[str]:
     """Only return the Noxfile value for sessions/keywords if neither sessions
     or keywords are specified on the command-line.
 
@@ -137,7 +139,7 @@ def _envdir_merge_func(
     return command_args.envdir or noxfile_args.envdir or ".nox"
 
 
-def _sessions_default() -> Optional[List[str]]:
+def _sessions_default() -> list[str] | None:
     """Looks at the NOXSESSION env var to set the default value for sessions."""
     nox_env = os.environ.get("NOXSESSION")
     env_sessions = nox_env.split(",") if nox_env else None
@@ -186,7 +188,7 @@ def _R_finalizer(value: bool, args: argparse.Namespace) -> bool:
 
 def _posargs_finalizer(
     value: Sequence[Any], args: argparse.Namespace
-) -> Union[Sequence[Any], List[Any]]:
+) -> Sequence[Any] | list[Any]:
     """Removes the leading "--"s in the posargs array (if any) and asserts that
     remaining arguments came after a "--".
     """
@@ -212,7 +214,7 @@ def _posargs_finalizer(
 
 def _session_completer(
     prefix: str, parsed_args: argparse.Namespace, **kwargs: Any
-) -> List[str]:
+) -> list[str]:
     global_config = parsed_args
     module = load_nox_module(global_config)
     manifest = discover_manifest(module, global_config)

nox/_parametrize.py

@@ -12,9 +12,11 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+from __future__ import annotations
+
 import functools
 import itertools
-from typing import Any, Callable, Dict, Iterable, List, Optional, Sequence, Tuple, Union
+from typing import Any, Callable, Iterable, Sequence, Union
 
 
 class Param:
@@ -31,8 +33,8 @@ class Param:
     def __init__(
         self,
         *args: Any,
-        arg_names: Optional[Sequence[str]] = None,
-        id: Optional[str] = None,
+        arg_names: Sequence[str] | None = None,
+        id: str | None = None,
     ) -> None:
         self.args = tuple(args)
         self.id = id
@@ -43,7 +45,7 @@ def __init__(
         self.arg_names = tuple(arg_names)
 
     @property
-    def call_spec(self) -> Dict[str, Any]:
+    def call_spec(self) -> dict[str, Any]:
         return dict(zip(self.arg_names, self.args))
 
     def __str__(self) -> str:
@@ -56,11 +58,11 @@ def __str__(self) -> str:
 
     __repr__ = __str__
 
-    def copy(self) -> "Param":
+    def copy(self) -> Param:
         new = self.__class__(*self.args, arg_names=self.arg_names, id=self.id)
         return new
 
-    def update(self, other: "Param") -> None:
+    def update(self, other: Param) -> None:
         self.id = ", ".join([str(self), str(other)])
         self.args = self.args + other.args
         self.arg_names = self.arg_names + other.arg_names
@@ -78,7 +80,7 @@ def __eq__(self, other: object) -> bool:
         raise NotImplementedError
 
 
-def _apply_param_specs(param_specs: List[Param], f: Any) -> Any:
+def _apply_param_specs(param_specs: list[Param], f: Any) -> Any:
     previous_param_specs = getattr(f, "parametrize", None)
     new_param_specs = update_param_specs(previous_param_specs, param_specs)
     f.parametrize = new_param_specs
@@ -89,9 +91,9 @@ def _apply_param_specs(param_specs: List[Param], f: Any) -> Any:
 
 
 def parametrize_decorator(
-    arg_names: Union[str, List[str], Tuple[str]],
-    arg_values_list: Union[Iterable[ArgValue], ArgValue],
-    ids: Optional[Iterable[Optional[str]]] = None,
+    arg_names: str | list[str] | tuple[str],
+    arg_values_list: Iterable[ArgValue] | ArgValue,
+    ids: Iterable[str | None] | None = None,
 ) -> Callable[[Any], Any]:
     """Parametrize a session.
 
@@ -119,7 +121,7 @@ def parametrize_decorator(
 
     # If there's only one arg_name, arg_values_list should be a single item
     # or list. Transform it so it'll work with the combine step.
-    _arg_values_list: List[Union[Param, Iterable[Union[Any, ArgValue]]]] = []
+    _arg_values_list: list[Param | Iterable[Any | ArgValue]] = []
     if len(arg_names) == 1:
         # In this case, the arg_values_list can also just be a single item.
         # Must be mutable for the transformation steps
@@ -141,7 +143,7 @@ def parametrize_decorator(
         ids = []
 
     # Generate params for each item in the param_args_values list.
-    param_specs: List[Param] = []
+    param_specs: list[Param] = []
     for param_arg_values, param_id in itertools.zip_longest(_arg_values_list, ids):
         if isinstance(param_arg_values, Param):
             param_spec = param_arg_values
@@ -155,8 +157,8 @@ def parametrize_decorator(
 
 
 def update_param_specs(
-    param_specs: Optional[Iterable[Param]], new_specs: List[Param]
-) -> List[Param]:
+    param_specs: Iterable[Param] | None, new_specs: list[Param]
+) -> list[Param]:
     """Produces all combinations of the given sets of specs."""
     if not param_specs:
         return new_specs

nox/_typing.py

@@ -12,6 +12,8 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+from __future__ import annotations
+
 __all__ = ["TYPE_CHECKING", "ClassVar", "NoReturn", "Python"]
 
 import typing as _typing