gh-109413: Add more type hints to `libregrtest` (#126352)

Lib/test/libregrtest/findtests.py

@@ -1,6 +1,7 @@
 import os
 import sys
 import unittest
+from collections.abc import Container
 
 from test import support
 
@@ -34,7 +35,7 @@ def findtestdir(path: StrPath | None = None) -> StrPath:
     return path or os.path.dirname(os.path.dirname(__file__)) or os.curdir
 
 
-def findtests(*, testdir: StrPath | None = None, exclude=(),
+def findtests(*, testdir: StrPath | None = None, exclude: Container[str] = (),
               split_test_dirs: set[TestName] = SPLITTESTDIRS,
               base_mod: str = "") -> TestList:
     """Return a list of all applicable test modules."""
@@ -60,8 +61,9 @@ def findtests(*, testdir: StrPath | None = None, exclude=(),
     return sorted(tests)
 
 
-def split_test_packages(tests, *, testdir: StrPath | None = None, exclude=(),
+def split_test_packages(tests, *, testdir: StrPath | None = None,
-                        split_test_dirs=SPLITTESTDIRS):
+                        exclude: Container[str] = (),
+                        split_test_dirs=SPLITTESTDIRS) -> list[TestName]:
     testdir = findtestdir(testdir)
     splitted = []
     for name in tests:
@@ -75,9 +77,9 @@ def split_test_packages(tests, *, testdir: StrPath | None = None, exclude=(),
     return splitted
 
 
-def _list_cases(suite):
+def _list_cases(suite: unittest.TestSuite) -> None:
     for test in suite:
-        if isinstance(test, unittest.loader._FailedTest):
+        if isinstance(test, unittest.loader._FailedTest):  # type: ignore[attr-defined]
             continue
         if isinstance(test, unittest.TestSuite):
             _list_cases(test)
@@ -87,7 +89,7 @@ def _list_cases(suite):
 
 def list_cases(tests: TestTuple, *,
                match_tests: TestFilter | None = None,
-               test_dir: StrPath | None = None):
+               test_dir: StrPath | None = None) -> None:
     support.verbose = False
     set_match_tests(match_tests)
 

Lib/test/libregrtest/main.py

@@ -6,6 +6,7 @@ import sys
 import sysconfig
 import time
 import trace
+from typing import NoReturn
 
 from test.support import os_helper, MS_WINDOWS, flush_std_streams
 
@@ -154,7 +155,7 @@ class Regrtest:
         self.next_single_test: TestName | None = None
         self.next_single_filename: StrPath | None = None
 
-    def log(self, line=''):
+    def log(self, line: str = '') -> None:
         self.logger.log(line)
 
     def find_tests(self, tests: TestList | None = None) -> tuple[TestTuple, TestList | None]:
@@ -230,11 +231,11 @@ class Regrtest:
         return (tuple(selected), tests)
 
     @staticmethod
-    def list_tests(tests: TestTuple):
+    def list_tests(tests: TestTuple) -> None:
         for name in tests:
             print(name)
 
-    def _rerun_failed_tests(self, runtests: RunTests):
+    def _rerun_failed_tests(self, runtests: RunTests) -> RunTests:
         # Configure the runner to re-run tests
         if self.num_workers == 0 and not self.single_process:
             # Always run tests in fresh processes to have more deterministic
@@ -266,7 +267,7 @@ class Regrtest:
             self.run_tests_sequentially(runtests)
         return runtests
 
-    def rerun_failed_tests(self, runtests: RunTests):
+    def rerun_failed_tests(self, runtests: RunTests) -> None:
         if self.python_cmd:
             # Temp patch for https://github.com/python/cpython/issues/94052
             self.log(
@@ -335,7 +336,7 @@ class Regrtest:
             if not self._run_bisect(runtests, name, progress):
                 return
 
-    def display_result(self, runtests):
+    def display_result(self, runtests: RunTests) -> None:
         # If running the test suite for PGO then no one cares about results.
         if runtests.pgo:
             return
@@ -365,7 +366,7 @@ class Regrtest:
 
         return result
 
-    def run_tests_sequentially(self, runtests) -> None:
+    def run_tests_sequentially(self, runtests: RunTests) -> None:
         if self.coverage:
             tracer = trace.Trace(trace=False, count=True)
         else:
@@ -422,7 +423,7 @@ class Regrtest:
         if previous_test:
             print(previous_test)
 
-    def get_state(self):
+    def get_state(self) -> str:
         state = self.results.get_state(self.fail_env_changed)
         if self.first_state:
             state = f'{self.first_state} then {state}'
@@ -452,7 +453,7 @@ class Regrtest:
         if self.junit_filename:
             self.results.write_junit(self.junit_filename)
 
-    def display_summary(self):
+    def display_summary(self) -> None:
         duration = time.perf_counter() - self.logger.start_time
         filtered = bool(self.match_tests)
 
@@ -466,7 +467,7 @@ class Regrtest:
         state = self.get_state()
         print(f"Result: {state}")
 
-    def create_run_tests(self, tests: TestTuple):
+    def create_run_tests(self, tests: TestTuple) -> RunTests:
         return RunTests(
             tests,
             fail_fast=self.fail_fast,
@@ -674,9 +675,9 @@ class Regrtest:
                           f"Command: {cmd_text}")
             # continue executing main()
 
-    def _add_python_opts(self):
+    def _add_python_opts(self) -> None:
-        python_opts = []
+        python_opts: list[str] = []
-        regrtest_opts = []
+        regrtest_opts: list[str] = []
 
         environ, keep_environ = self._add_cross_compile_opts(regrtest_opts)
         if self.ci_mode:
@@ -709,7 +710,7 @@ class Regrtest:
 
         self.tmp_dir = get_temp_dir(self.tmp_dir)
 
-    def main(self, tests: TestList | None = None):
+    def main(self, tests: TestList | None = None) -> NoReturn:
         if self.want_add_python_opts:
             self._add_python_opts()
 
@@ -738,7 +739,7 @@ class Regrtest:
         sys.exit(exitcode)
 
 
-def main(tests=None, _add_python_opts=False, **kwargs):
+def main(tests=None, _add_python_opts=False, **kwargs) -> NoReturn:
     """Run the Python suite."""
     ns = _parse_args(sys.argv[1:], **kwargs)
     Regrtest(ns, _add_python_opts=_add_python_opts).main(tests=tests)

Lib/test/libregrtest/pgo.py

@@ -50,7 +50,7 @@ PGO_TESTS = [
     'test_xml_etree_c',
 ]
 
-def setup_pgo_tests(cmdline_args, pgo_extended: bool):
+def setup_pgo_tests(cmdline_args, pgo_extended: bool) -> None:
     if not cmdline_args and not pgo_extended:
         # run default set of tests for PGO training
         cmdline_args[:] = PGO_TESTS[:]

Lib/test/libregrtest/refleak.py

@@ -262,7 +262,7 @@ def dash_R_cleanup(fs, ps, pic, zdc, abcs):
     sys._clear_internal_caches()
 
 
-def warm_caches():
+def warm_caches() -> None:
     # char cache
     s = bytes(range(256))
     for i in range(256):

Lib/test/libregrtest/result.py

@@ -149,6 +149,7 @@ class TestResult:
             case State.DID_NOT_RUN:
                 return f"{self.test_name} ran no tests"
             case State.TIMEOUT:
+                assert self.duration is not None, "self.duration is None"
                 return f"{self.test_name} timed out ({format_duration(self.duration)})"
             case _:
                 raise ValueError("unknown result state: {state!r}")

Lib/test/libregrtest/results.py

@@ -71,7 +71,7 @@ class TestResults:
 
         return ', '.join(state)
 
-    def get_exitcode(self, fail_env_changed, fail_rerun):
+    def get_exitcode(self, fail_env_changed: bool, fail_rerun: bool) -> int:
         exitcode = 0
         if self.bad:
             exitcode = EXITCODE_BAD_TEST
@@ -87,7 +87,7 @@ class TestResults:
             exitcode = EXITCODE_BAD_TEST
         return exitcode
 
-    def accumulate_result(self, result: TestResult, runtests: RunTests):
+    def accumulate_result(self, result: TestResult, runtests: RunTests) -> None:
         test_name = result.test_name
         rerun = runtests.rerun
         fail_env_changed = runtests.fail_env_changed
@@ -135,7 +135,7 @@ class TestResults:
         counts = {loc: 1 for loc in self.covered_lines}
         return trace.CoverageResults(counts=counts)
 
-    def need_rerun(self):
+    def need_rerun(self) -> bool:
         return bool(self.rerun_results)
 
     def prepare_rerun(self, *, clear: bool = True) -> tuple[TestTuple, FilterDict]:
@@ -158,7 +158,7 @@ class TestResults:
 
         return (tuple(tests), match_tests_dict)
 
-    def add_junit(self, xml_data: list[str]):
+    def add_junit(self, xml_data: list[str]) -> None:
         import xml.etree.ElementTree as ET
         for e in xml_data:
             try:
@@ -167,7 +167,7 @@ class TestResults:
                 print(xml_data, file=sys.__stderr__)
                 raise
 
-    def write_junit(self, filename: StrPath):
+    def write_junit(self, filename: StrPath) -> None:
         if not self.testsuite_xml:
             # Don't create empty XML file
             return
@@ -192,7 +192,7 @@ class TestResults:
             for s in ET.tostringlist(root):
                 f.write(s)
 
-    def display_result(self, tests: TestTuple, quiet: bool, print_slowest: bool):
+    def display_result(self, tests: TestTuple, quiet: bool, print_slowest: bool) -> None:
         if print_slowest:
             self.test_times.sort(reverse=True)
             print()
@@ -234,7 +234,7 @@ class TestResults:
             print()
             print("Test suite interrupted by signal SIGINT.")
 
-    def display_summary(self, first_runtests: RunTests, filtered: bool):
+    def display_summary(self, first_runtests: RunTests, filtered: bool) -> None:
         # Total tests
         stats = self.stats
         text = f'run={stats.tests_run:,}'

Lib/test/libregrtest/runtests.py

@@ -5,12 +5,12 @@ import os
 import shlex
 import subprocess
 import sys
-from typing import Any
+from typing import Any, Iterator
 
 from test import support
 
 from .utils import (
-    StrPath, StrJSON, TestTuple, TestFilter, FilterTuple, FilterDict)
+    StrPath, StrJSON, TestTuple, TestName, TestFilter, FilterTuple, FilterDict)
 
 
 class JsonFileType:
@@ -41,8 +41,8 @@ class JsonFile:
                 popen_kwargs['startupinfo'] = startupinfo
 
     @contextlib.contextmanager
-    def inherit_subprocess(self):
+    def inherit_subprocess(self) -> Iterator[None]:
-        if self.file_type == JsonFileType.WINDOWS_HANDLE:
+        if sys.platform == 'win32' and self.file_type == JsonFileType.WINDOWS_HANDLE:
             os.set_handle_inheritable(self.file, True)
             try:
                 yield
@@ -106,25 +106,25 @@ class RunTests:
         state.update(override)
         return RunTests(**state)
 
-    def create_worker_runtests(self, **override):
+    def create_worker_runtests(self, **override) -> WorkerRunTests:
         state = dataclasses.asdict(self)
         state.update(override)
         return WorkerRunTests(**state)
 
-    def get_match_tests(self, test_name) -> FilterTuple | None:
+    def get_match_tests(self, test_name: TestName) -> FilterTuple | None:
         if self.match_tests_dict is not None:
             return self.match_tests_dict.get(test_name, None)
         else:
             return None
 
-    def get_jobs(self):
+    def get_jobs(self) -> int | None:
         # Number of run_single_test() calls needed to run all tests.
         # None means that there is not bound limit (--forever option).
         if self.forever:
             return None
         return len(self.tests)
 
-    def iter_tests(self):
+    def iter_tests(self) -> Iterator[TestName]:
         if self.forever:
             while True:
                 yield from self.tests

Lib/test/libregrtest/setup.py

@@ -25,9 +25,10 @@ def setup_test_dir(testdir: str | None) -> None:
         sys.path.insert(0, os.path.abspath(testdir))
 
 
-def setup_process():
+def setup_process() -> None:
     fix_umask()
 
+    assert sys.__stderr__ is not None, "sys.__stderr__ is None"
     try:
         stderr_fd = sys.__stderr__.fileno()
     except (ValueError, AttributeError):
@@ -35,7 +36,7 @@ def setup_process():
         # and ValueError on a closed stream.
         #
         # Catch AttributeError for stderr being None.
-        stderr_fd = None
+        pass
     else:
         # Display the Python traceback on fatal errors (e.g. segfault)
         faulthandler.enable(all_threads=True, file=stderr_fd)
@@ -68,7 +69,7 @@ def setup_process():
             for index, path in enumerate(module.__path__):
                 module.__path__[index] = os.path.abspath(path)
         if getattr(module, '__file__', None):
-            module.__file__ = os.path.abspath(module.__file__)
+            module.__file__ = os.path.abspath(module.__file__)  # type: ignore[type-var]
 
     if hasattr(sys, 'addaudithook'):
         # Add an auditing hook for all tests to ensure PySys_Audit is tested
@@ -87,7 +88,7 @@ def setup_process():
         os.environ.setdefault(UNICODE_GUARD_ENV, FS_NONASCII)
 
 
-def setup_tests(runtests: RunTests):
+def setup_tests(runtests: RunTests) -> None:
     support.verbose = runtests.verbose
     support.failfast = runtests.fail_fast
     support.PGO = runtests.pgo

Lib/test/libregrtest/tsan.py

@@ -28,6 +28,6 @@ TSAN_TESTS = [
 ]
 
 
-def setup_tsan_tests(cmdline_args):
+def setup_tsan_tests(cmdline_args) -> None:
     if not cmdline_args:
         cmdline_args[:] = TSAN_TESTS[:]

Lib/test/libregrtest/utils.py

@@ -58,7 +58,7 @@ FilterTuple = tuple[TestName, ...]
 FilterDict = dict[TestName, FilterTuple]
 
 
-def format_duration(seconds):
+def format_duration(seconds: float) -> str:
     ms = math.ceil(seconds * 1e3)
     seconds, ms = divmod(ms, 1000)
     minutes, seconds = divmod(seconds, 60)
@@ -92,7 +92,7 @@ def strip_py_suffix(names: list[str] | None) -> None:
             names[idx] = basename
 
 
-def plural(n, singular, plural=None):
+def plural(n: int, singular: str, plural: str | None = None) -> str:
     if n == 1:
         return singular
     elif plural is not None:
@@ -101,7 +101,7 @@ def plural(n, singular, plural=None):
         return singular + 's'
 
 
-def count(n, word):
+def count(n: int, word: str) -> str:
     if n == 1:
         return f"{n} {word}"
     else:
@@ -123,14 +123,14 @@ def printlist(x, width=70, indent=4, file=None):
           file=file)
 
 
-def print_warning(msg):
+def print_warning(msg: str) -> None:
     support.print_warning(msg)
 
 
-orig_unraisablehook = None
+orig_unraisablehook: Callable[..., None] | None = None
 
 
-def regrtest_unraisable_hook(unraisable):
+def regrtest_unraisable_hook(unraisable) -> None:
     global orig_unraisablehook
     support.environment_altered = True
     support.print_warning("Unraisable exception")
@@ -138,22 +138,23 @@ def regrtest_unraisable_hook(unraisable):
     try:
         support.flush_std_streams()
         sys.stderr = support.print_warning.orig_stderr
+        assert orig_unraisablehook is not None, "orig_unraisablehook not set"
         orig_unraisablehook(unraisable)
         sys.stderr.flush()
     finally:
         sys.stderr = old_stderr
 
 
-def setup_unraisable_hook():
+def setup_unraisable_hook() -> None:
     global orig_unraisablehook
     orig_unraisablehook = sys.unraisablehook
     sys.unraisablehook = regrtest_unraisable_hook
 
 
-orig_threading_excepthook = None
+orig_threading_excepthook: Callable[..., None] | None = None
 
 
-def regrtest_threading_excepthook(args):
+def regrtest_threading_excepthook(args) -> None:
     global orig_threading_excepthook
     support.environment_altered = True
     support.print_warning(f"Uncaught thread exception: {args.exc_type.__name__}")
@@ -161,13 +162,14 @@ def regrtest_threading_excepthook(args):
     try:
         support.flush_std_streams()
         sys.stderr = support.print_warning.orig_stderr
+        assert orig_threading_excepthook is not None, "orig_threading_excepthook not set"
         orig_threading_excepthook(args)
         sys.stderr.flush()
     finally:
         sys.stderr = old_stderr
 
 
-def setup_threading_excepthook():
+def setup_threading_excepthook() -> None:
     global orig_threading_excepthook
     import threading
     orig_threading_excepthook = threading.excepthook
@@ -476,7 +478,7 @@ def get_temp_dir(tmp_dir: StrPath | None = None) -> StrPath:
     return os.path.abspath(tmp_dir)
 
 
-def fix_umask():
+def fix_umask() -> None:
     if support.is_emscripten:
         # Emscripten has default umask 0o777, which breaks some tests.
         # see https://github.com/emscripten-core/emscripten/issues/17269
@@ -572,7 +574,8 @@ _TEST_LIFECYCLE_HOOKS = frozenset((
     'setUpModule', 'tearDownModule',
 ))
 
-def normalize_test_name(test_full_name, *, is_error=False):
+def normalize_test_name(test_full_name: str, *,
+                        is_error: bool = False) -> str | None:
     short_name = test_full_name.split(" ")[0]
     if is_error and short_name in _TEST_LIFECYCLE_HOOKS:
         if test_full_name.startswith(('setUpModule (', 'tearDownModule (')):
@@ -593,7 +596,7 @@ def normalize_test_name(test_full_name, *, is_error=False):
     return short_name
 
 
-def adjust_rlimit_nofile():
+def adjust_rlimit_nofile() -> None:
     """
     On macOS the default fd limit (RLIMIT_NOFILE) is sometimes too low (256)
     for our test suite to succeed. Raise it to something more reasonable. 1024
@@ -619,17 +622,17 @@ def adjust_rlimit_nofile():
                           f"{new_fd_limit}: {err}.")
 
 
-def get_host_runner():
+def get_host_runner() -> str:
     if (hostrunner := os.environ.get("_PYTHON_HOSTRUNNER")) is None:
         hostrunner = sysconfig.get_config_var("HOSTRUNNER")
     return hostrunner
 
 
-def is_cross_compiled():
+def is_cross_compiled() -> bool:
     return ('_PYTHON_HOST_PLATFORM' in os.environ)
 
 
-def format_resources(use_resources: Iterable[str]):
+def format_resources(use_resources: Iterable[str]) -> str:
     use_resources = set(use_resources)
     all_resources = set(ALL_RESOURCES)
 
@@ -654,7 +657,7 @@ def format_resources(use_resources: Iterable[str]):
 
 
 def display_header(use_resources: tuple[str, ...],
-                   python_cmd: tuple[str, ...] | None):
+                   python_cmd: tuple[str, ...] | None) -> None:
     # Print basic platform information
     print("==", platform.python_implementation(), *sys.version.split())
     print("==", platform.platform(aliased=True),
@@ -732,7 +735,7 @@ def display_header(use_resources: tuple[str, ...],
     print(flush=True)
 
 
-def cleanup_temp_dir(tmp_dir: StrPath):
+def cleanup_temp_dir(tmp_dir: StrPath) -> None:
     import glob
 
     path = os.path.join(glob.escape(tmp_dir), TMP_PREFIX + '*')
@@ -763,5 +766,5 @@ def _sanitize_xml_replace(regs):
     return ''.join(f'\\x{ord(ch):02x}' if ch <= '\xff' else ascii(ch)[1:-1]
                    for ch in text)
 
-def sanitize_xml(text):
+def sanitize_xml(text: str) -> str:
     return ILLEGAL_XML_CHARS_RE.sub(_sanitize_xml_replace, text)

Lib/test/libregrtest/worker.py

@@ -104,7 +104,7 @@ def worker_process(worker_json: StrJSON) -> NoReturn:
     sys.exit(0)
 
 
-def main():
+def main() -> NoReturn:
     if len(sys.argv) != 2:
         print("usage: python -m test.libregrtest.worker JSON")
         sys.exit(1)

Tools/requirements-dev.txt

@@ -1,6 +1,6 @@
 # Requirements file for external linters and checks we run on
 # Tools/clinic, Tools/cases_generator/, and Tools/peg_generator/ in CI
-mypy==1.12
+mypy==1.13
 
 # needed for peg_generator:
 types-psutil==6.0.0.20240901