gh-160936: Check cache state before and after in the new logging tests

Author: Ar-maan05

Lib/test/test_logging.py

@@ -6401,21 +6401,32 @@ def test_pickling(self):
     def test_caching_unregistered_logger(self):
         # A logger that is not in loggerDict must not keep a stale cache.
         logger = logging.Logger("unregistered")
+        self.assertEqual(logger._cache, {})
         logger.setLevel(logging.DEBUG)
+        self.assertEqual(logger._cache, {})
         self.assertTrue(logger.isEnabledFor(logging.DEBUG))
+        self.assertEqual(logger._cache, {logging.DEBUG: True})
         logger.setLevel(logging.ERROR)
         self.assertEqual(logger._cache, {})
         self.assertFalse(logger.isEnabledFor(logging.DEBUG))
+        self.assertEqual(logger._cache, {logging.DEBUG: False})
 
     def test_clear_cache_empties_cached_loggers(self):
         manager = logging.root.manager
         registered = logging.getLogger("cached.registered")
         unregistered = logging.Logger("cached.unregistered")
+        # Start from a known state: other tests may have cached results.
+        manager._clear_cache()
+        self.assertEqual(len(manager._cached_loggers), 0)
         for logger in (registered, unregistered):
             logger.isEnabledFor(logging.DEBUG)
             self.assertIn(logger, manager._cached_loggers)
+        self.assertEqual(len(manager._cached_loggers), 2)
         registered.setLevel(logging.INFO)
         self.assertEqual(len(manager._cached_loggers), 0)
+        # A later cache miss starts tracking the logger again.
+        registered.isEnabledFor(logging.DEBUG)
+        self.assertEqual(list(manager._cached_loggers), [registered])
 
     def test_caching(self):
         root = self.root_logger