gh-119050: Implement --duration option for the test suite CLI

Lib/test/libregrtest/cmdline.py

@@ -252,6 +252,9 @@ def _create_parser():
                        help='no output unless one or more tests fail')
     group.add_argument('-o', '--slowest', action='store_true', dest='print_slow',
                        help='print the slowest 10 tests')
+    group.add_argument('--duration', dest="durationpath", metavar='DURATION_FILE',
+                       help='writes information about the duration '
+                        'of the tests to a file')
     group.add_argument('--header', action='store_true',
                        help='print header with interpreter info')
 

Lib/test/libregrtest/main.py

@@ -123,6 +123,7 @@ def __init__(self, ns: Namespace, _add_python_opts: bool = False):
         self.coverage: bool = ns.trace
         self.coverage_dir: StrPath | None = ns.coverdir
         self.tmp_dir: StrPath | None = ns.tempdir
+        self.duration_filename: StrPath | None = ns.durationpath
 
         # Randomize
         self.randomize: bool = ns.randomize
@@ -445,6 +446,9 @@ def finalize_tests(self, coverage: trace.CoverageResults | None) -> None:
         if self.junit_filename:
             self.results.write_junit(self.junit_filename)
 
+        if self.duration_filename:
+            self.results.write_duration(self.duration_filename)
+
     def display_summary(self):
         duration = time.perf_counter() - self.logger.start_time
         filtered = bool(self.match_tests)
@@ -484,6 +488,7 @@ def create_run_tests(self, tests: TestTuple):
             python_cmd=self.python_cmd,
             randomize=self.randomize,
             random_seed=self.random_seed,
+            with_duration=(self.duration_filename is not None),
         )
 
     def _run_tests(self, selected: TestTuple, tests: TestList | None) -> int:
@@ -691,14 +696,22 @@ def _add_python_opts(self):
 
         self._execute_python(cmd, environ)
 
+    def normalize_path(self, filename: StrPath) -> StrPath:
+        if not os.path.isabs(filename):
+            return os.path.abspath(filename)
+        return filename
+
     def _init(self):
         # Set sys.stdout encoder error handler to backslashreplace,
         # similar to sys.stderr error handler, to avoid UnicodeEncodeError
         # when printing a traceback or any other non-encodable character.
         sys.stdout.reconfigure(errors="backslashreplace")
 
-        if self.junit_filename and not os.path.isabs(self.junit_filename):
-            self.junit_filename = os.path.abspath(self.junit_filename)
+        if self.junit_filename:
+            self.junit_filename = self.normalize_path(self.junit_filename)
+
+        if self.duration_filename:
+            self.duration_filename = self.normalize_path(self.duration_filename)
 
         strip_py_suffix(self.cmdline_args)
 

Lib/test/libregrtest/results.py

@@ -192,6 +192,12 @@ def write_junit(self, filename: StrPath):
             for s in ET.tostringlist(root):
                 f.write(s)
 
+    def write_duration(self, filename: StrPath):
+        self.test_times.sort(reverse=True)
+        with open(filename, 'w', encoding='utf8') as f:
+            for test_time, test in self.test_times:
+                f.write(f"{test}: {format_duration(test_time)}\n")
+
     def display_result(self, tests: TestTuple, quiet: bool, print_slowest: bool):
         if print_slowest:
             self.test_times.sort(reverse=True)

Lib/test/libregrtest/runtests.py

@@ -100,6 +100,7 @@ class RunTests:
     python_cmd: tuple[str, ...] | None
     randomize: bool
     random_seed: int | str
+    with_duration: bool
 
     def copy(self, **override) -> 'RunTests':
         state = dataclasses.asdict(self)

Lib/test/test_regrtest.py

@@ -482,6 +482,11 @@ def test_xml_huntrleaks(self):
         self.assertEqual(regrtest.hunt_refleak.runs, 12)
         self.assertIsNone(regrtest.junit_filename)
 
+    def test_duration(self):
+        args = ['--duration', 'output']
+        regrtest = self.create_regrtest(args)
+        self.assertIsNotNone(regrtest.duration_filename)
+
 
 @dataclasses.dataclass(slots=True)
 class Rerun:

Misc/NEWS.d/next/Tests/2024-05-14-23-14-01.gh-issue-119050.Nvdq9L.rst

@@ -0,0 +1,3 @@
+Add a ``--duration`` option to the test suite.
+This option is similar to the already existing ``--slowest``,
+but writes the duration of each test to a file specified by the user.