Add failing test for partial date with leap day

lucc · lucc · commit 54455e29b68b · 2026-02-18T08:14:40.000+01:00
Python uses 1900 as the default year if a partial date is parsed with datetime.datetime.strptime. This fails for February 29th because 1900 is not a leap year. This is discussed in #335 and upstream in python/cpython#116179.
diff --git a/test/test_helpers_typing.py b/test/test_helpers_typing.py
@@ -149,3 +149,11 @@ def test_yyyy_mm_ddThh_mm_ssz_format(self):
         string = "1900-01-02T06:42:17-06:00"
         result = string_to_date(string)
         self.assertEqual(result, self.zone)
+
+    @unittest.expectedFailure
+    def test_partial_date_with_february_29(self):
+        # FIXME: this fails because 1900 is not a leap year, see
+        # https://github.com/python/cpython/pull/116179 for more info.
+        string = "--02-29"
+        result = string_to_date(string)
+        self.assertEqual(result, datetime.datetime(year=1900, month=2, day=29))
