Use `from __future__ import annotations`

Allows us to use more modern typing.

pyproject.toml

@@ -85,6 +85,7 @@ select = [
     "W",        # pycodestyle
     "T10",      # flake8-debugger
     "PIE",      # flake8-pie
+    "FA",       # flake8-future-annotations
     "PGH",      # pygrep-hooks
     "PLE",      # pylint error
     "PLW",      # pylint warning

src/xdist/looponfail.py

@@ -7,11 +7,12 @@ processes) otherwise changes to source code can crash
 the controlling process which should best never happen.
 """
 
+from __future__ import annotations
+
 import os
 from pathlib import Path
 import sys
 import time
-from typing import Dict
 from typing import Sequence
 
 from _pytest._io import TerminalWriter
@@ -45,7 +46,7 @@ def pytest_cmdline_main(config):
         return 2  # looponfail only can get stop with ctrl-C anyway
 
 
-def looponfail_main(config: "pytest.Config") -> None:
+def looponfail_main(config: pytest.Config) -> None:
     remotecontrol = RemoteControl(config)
     config_roots = config.getini("looponfailroots")
     if not config_roots:
@@ -238,7 +239,7 @@ class WorkerFailSession:
 class StatRecorder:
     def __init__(self, rootdirlist: Sequence[Path]) -> None:
         self.rootdirlist = rootdirlist
-        self.statcache: Dict[Path, os.stat_result] = {}
+        self.statcache: dict[Path, os.stat_result] = {}
         self.check()  # snapshot state
 
     def fil(self, p: Path) -> bool:
@@ -256,7 +257,7 @@ class StatRecorder:
 
     def check(self, removepycfiles: bool = True) -> bool:
         changed = False
-        newstat: Dict[Path, os.stat_result] = {}
+        newstat: dict[Path, os.stat_result] = {}
         for rootdir in self.rootdirlist:
             for path in visit_path(rootdir, filter=self.fil, recurse=self.rec):
                 oldstat = self.statcache.pop(path, None)

src/xdist/workermanage.py

@@ -7,11 +7,7 @@ from pathlib import Path
 import re
 import sys
 from typing import Any
-from typing import List
-from typing import Optional
 from typing import Sequence
-from typing import Set
-from typing import Tuple
 from typing import Union
 import uuid
 
@@ -63,7 +59,7 @@ class NodeManager:
             self.specs.append(spec)
         self.roots = self._getrsyncdirs()
         self.rsyncoptions = self._getrsyncoptions()
-        self._rsynced_specs: Set[Tuple[Any, Any]] = set()
+        self._rsynced_specs: set[tuple[Any, Any]] = set()
 
     def rsync_roots(self, gateway):
         """Rsync the set of roots to the node's gateway cwd."""
@@ -92,7 +88,7 @@ class NodeManager:
     def _getxspecs(self):
         return [execnet.XSpec(x) for x in parse_spec_config(self.config)]
 
-    def _getrsyncdirs(self) -> List[Path]:
+    def _getrsyncdirs(self) -> list[Path]:
         for spec in self.specs:
             if not spec.popen or spec.chdir:
                 break
@@ -177,7 +173,7 @@ class HostRSync(execnet.RSync):
         self,
         sourcedir: PathLike,
         *,
-        ignores: Optional[Sequence[PathLike]] = None,
+        ignores: Sequence[PathLike] | None = None,
         verbose: bool = True,
     ) -> None:
         if ignores is None:
@@ -204,7 +200,7 @@ class HostRSync(execnet.RSync):
             print(f"{gateway.spec}:{remotepath} <= {path}")
 
 
-def make_reltoroot(roots: Sequence[Path], args: List[str]) -> List[str]:
+def make_reltoroot(roots: Sequence[Path], args: list[str]) -> list[str]:
     # XXX introduce/use public API for splitting pytest args
     splitcode = "::"
     result = []
@@ -219,7 +215,7 @@ def make_reltoroot(roots: Sequence[Path], args: List[str]) -> List[str]:
             result.append(arg)
             continue
         for root in roots:
-            x: Optional[Path]
+            x: Path | None
             try:
                 x = fspath.relative_to(root)
             except ValueError:

testing/acceptance_test.py

@@ -1,9 +1,8 @@
+from __future__ import annotations
+
 import os
 import re
 import shutil
-from typing import Dict
-from typing import List
-from typing import Tuple
 
 import pytest
 
@@ -1528,7 +1527,7 @@ class TestLocking:
         result.assert_outcomes(passed=(48 if scope != "each" else 48 * 2))
 
 
-def parse_tests_and_workers_from_output(lines: List[str]) -> List[Tuple[str, str, str]]:
+def parse_tests_and_workers_from_output(lines: list[str]) -> list[tuple[str, str, str]]:
     result = []
     for line in lines:
         # example match: "[gw0] PASSED test_a.py::test[7]"
@@ -1550,9 +1549,9 @@ def parse_tests_and_workers_from_output(lines: List[str]) -> List[Tuple[str, str
 
 
 def get_workers_and_test_count_by_prefix(
-    prefix: str, lines: List[str], expected_status: str = "PASSED"
-) -> Dict[str, int]:
-    result: Dict[str, int] = {}
+    prefix: str, lines: list[str], expected_status: str = "PASSED"
+) -> dict[str, int]:
+    result: dict[str, int] = {}
     for worker, status, nodeid in parse_tests_and_workers_from_output(lines):
         if expected_status == status and nodeid.startswith(prefix):
             result[worker] = result.get(worker, 0) + 1

testing/conftest.py

@@ -1,5 +1,6 @@
+from __future__ import annotations
+
 import shutil
-from typing import List
 
 import execnet
 import pytest
@@ -41,7 +42,7 @@ def specssh(request) -> str:
 
 
 # configuration information for tests
-def getgspecs(config) -> List[execnet.XSpec]:
+def getgspecs(config) -> list[execnet.XSpec]:
     return [execnet.XSpec(spec) for spec in config.getvalueorskip("gspecs")]
 
 

testing/test_looponfail.py

@@ -1,9 +1,10 @@
+from __future__ import annotations
+
 import pathlib
 from pathlib import Path
 import shutil
 import tempfile
 import textwrap
-from typing import List
 import unittest.mock
 
 import pytest
@@ -75,7 +76,7 @@ class TestStatRecorder:
         # make check()'s visit() call return our just removed
         # path as if we were in a race condition
         dirname = str(tmp)
-        dirnames: List[str] = []
+        dirnames: list[str] = []
         filenames = [str(p)]
         with unittest.mock.patch(
             "os.walk", return_value=[(dirname, dirnames, filenames)], autospec=True