diff --git a/direct/src/directnotify/DirectNotify.py b/direct/src/directnotify/DirectNotify.py
index d2e2ba4a3e..f7c7e6c964 100644
--- a/direct/src/directnotify/DirectNotify.py
+++ b/direct/src/directnotify/DirectNotify.py
@@ -2,6 +2,10 @@
 DirectNotify module: this module contains the DirectNotify class
 """
 
+from __future__ import annotations
+
+from panda3d.core import StreamWriter
+
 from . import Notifier
 from . import Logger
 
@@ -12,39 +16,39 @@ class DirectNotify:
     mulitple notify categories via a dictionary of Notifiers.
     """
 
-    def __init__(self):
+    def __init__(self) -> None:
         """
         DirectNotify class keeps a dictionary of Notfiers
         """
-        self.__categories = {}
+        self.__categories: dict[str, Notifier.Notifier] = {}
         # create a default log file
         self.logger = Logger.Logger()
 
         # This will get filled in later by ShowBase.py with a
         # C++-level StreamWriter object for writing to standard
         # output.
-        self.streamWriter = None
+        self.streamWriter: StreamWriter | None = None
 
-    def __str__(self):
+    def __str__(self) -> str:
         """
         Print handling routine
         """
         return "DirectNotify categories: %s" % (self.__categories)
 
     #getters and setters
-    def getCategories(self):
+    def getCategories(self) -> list[str]:
         """
         Return list of category dictionary keys
         """
         return list(self.__categories.keys())
 
-    def getCategory(self, categoryName):
+    def getCategory(self, categoryName: str) -> Notifier.Notifier | None:
         """getCategory(self, string)
         Return the category with given name if present, None otherwise
         """
         return self.__categories.get(categoryName, None)
 
-    def newCategory(self, categoryName, logger=None):
+    def newCategory(self, categoryName: str, logger: Logger.Logger | None = None) -> Notifier.Notifier:
         """newCategory(self, string)
         Make a new notify category named categoryName. Return new category
         if no such category exists, else return existing category
@@ -52,9 +56,11 @@ class DirectNotify:
         if categoryName not in self.__categories:
             self.__categories[categoryName] = Notifier.Notifier(categoryName, logger)
             self.setDconfigLevel(categoryName)
-        return self.getCategory(categoryName)
+        notifier = self.getCategory(categoryName)
+        assert notifier is not None
+        return notifier
 
-    def setDconfigLevel(self, categoryName):
+    def setDconfigLevel(self, categoryName: str) -> None:
         """
         Check to see if this category has a dconfig variable
         to set the notify severity and then set that level. You cannot
@@ -77,40 +83,42 @@ class DirectNotify:
             level = 'error'
 
         category = self.getCategory(categoryName)
+        assert category is not None, f'failed to find category: {categoryName!r}'
         # Note - this print statement is making it difficult to
         # achieve "no output unless there's an error" operation - Josh
         # print ("Setting DirectNotify category: " + categoryName +
         #        " to severity: " + level)
         if level == "error":
-            category.setWarning(0)
-            category.setInfo(0)
-            category.setDebug(0)
+            category.setWarning(False)
+            category.setInfo(False)
+            category.setDebug(False)
         elif level == "warning":
-            category.setWarning(1)
-            category.setInfo(0)
-            category.setDebug(0)
+            category.setWarning(True)
+            category.setInfo(False)
+            category.setDebug(False)
         elif level == "info":
-            category.setWarning(1)
-            category.setInfo(1)
-            category.setDebug(0)
+            category.setWarning(True)
+            category.setInfo(True)
+            category.setDebug(False)
         elif level == "debug":
-            category.setWarning(1)
-            category.setInfo(1)
-            category.setDebug(1)
+            category.setWarning(True)
+            category.setInfo(True)
+            category.setDebug(True)
         else:
             print("DirectNotify: unknown notify level: " + str(level)
                    + " for category: " + str(categoryName))
 
-    def setDconfigLevels(self):
+    def setDconfigLevels(self) -> None:
         for categoryName in self.getCategories():
             self.setDconfigLevel(categoryName)
 
-    def setVerbose(self):
+    def setVerbose(self) -> None:
         for categoryName in self.getCategories():
             category = self.getCategory(categoryName)
-            category.setWarning(1)
-            category.setInfo(1)
-            category.setDebug(1)
+            assert category is not None
+            category.setWarning(True)
+            category.setInfo(True)
+            category.setDebug(True)
 
     def popupControls(self, tl = None):
         # Don't use a regular import, to prevent ModuleFinder from picking
@@ -119,5 +127,5 @@ class DirectNotify:
         NotifyPanel = importlib.import_module('direct.tkpanels.NotifyPanel')
         NotifyPanel.NotifyPanel(self, tl)
 
-    def giveNotify(self,cls):
+    def giveNotify(self, cls) -> None:
         cls.notify = self.newCategory(cls.__name__)
diff --git a/direct/src/directnotify/Logger.py b/direct/src/directnotify/Logger.py
index 0c5aeaab04..21418592ec 100644
--- a/direct/src/directnotify/Logger.py
+++ b/direct/src/directnotify/Logger.py
@@ -1,27 +1,30 @@
 """Logger module: contains the logger class which creates and writes
    data to log files on disk"""
 
+from __future__ import annotations
+
+import io
 import time
 import math
 
 
 class Logger:
-    def __init__(self, fileName="log"):
+    def __init__(self, fileName: str = "log") -> None:
         """
         Logger constructor
         """
-        self.__timeStamp = 1
+        self.__timeStamp = True
         self.__startTime = 0.0
-        self.__logFile = None
+        self.__logFile: io.TextIOWrapper | None = None
         self.__logFileName = fileName
 
-    def setTimeStamp(self, enable):
+    def setTimeStamp(self, enable: bool) -> None:
         """
         Toggle time stamp printing with log entries on and off
         """
         self.__timeStamp = enable
 
-    def getTimeStamp(self):
+    def getTimeStamp(self) -> bool:
         """
         Return whether or not we are printing time stamps with log entries
         """
@@ -29,24 +32,25 @@ class Logger:
 
     # logging control
 
-    def resetStartTime(self):
+    def resetStartTime(self) -> None:
         """
         Reset the start time of the log file for time stamps
         """
         self.__startTime = time.time()
 
-    def log(self, entryString):
+    def log(self, entryString: str) -> None:
         """log(self, string)
         Print the given string to the log file"""
         if self.__logFile is None:
             self.__openLogFile()
+        assert self.__logFile is not None
         if self.__timeStamp:
             self.__logFile.write(self.__getTimeStamp())
         self.__logFile.write(entryString + '\n')
 
     # logging functions
 
-    def __openLogFile(self):
+    def __openLogFile(self) -> None:
         """
         Open a file for logging error/warning messages
         """
@@ -56,14 +60,14 @@ class Logger:
         logFileName = self.__logFileName + "." + st
         self.__logFile = open(logFileName, "w")
 
-    def __closeLogFile(self):
+    def __closeLogFile(self) -> None:
         """
         Close the error/warning output file
         """
         if self.__logFile is not None:
             self.__logFile.close()
 
-    def __getTimeStamp(self):
+    def __getTimeStamp(self) -> str:
         """
         Return the offset between current time and log file startTime
         """
diff --git a/direct/src/directnotify/Notifier.py b/direct/src/directnotify/Notifier.py
index 8a49ab5564..bf3f14779a 100644
--- a/direct/src/directnotify/Notifier.py
+++ b/direct/src/directnotify/Notifier.py
@@ -2,11 +2,16 @@
 Notifier module: contains methods for handling information output
 for the programmer/user
 """
+
+from __future__ import annotations
+
+from .Logger import Logger
 from .LoggerGlobal import defaultLogger
 from direct.showbase import PythonUtil
 from panda3d.core import ConfigVariableBool, NotifyCategory, StreamWriter, Notify
 import time
 import sys
+from typing import NoReturn
 
 
 class NotifierException(Exception):
@@ -20,13 +25,13 @@ class Notifier:
     # messages instead of writing them to the console.  This is
     # particularly useful for integrating the Python notify system
     # with the C++ notify system.
-    streamWriter = None
+    streamWriter: StreamWriter | None = None
     if ConfigVariableBool('notify-integrate', True):
         streamWriter = StreamWriter(Notify.out(), False)
 
     showTime = ConfigVariableBool('notify-timestamp', False)
 
-    def __init__(self, name, logger=None):
+    def __init__(self, name: str, logger: Logger | None = None) -> None:
         """
         Parameters:
             name (str): a string name given to this Notifier instance.
@@ -42,12 +47,12 @@ class Notifier:
             self.__logger = logger
 
         # Global default levels are initialized here
-        self.__info = 1
-        self.__warning = 1
-        self.__debug = 0
-        self.__logging = 0
+        self.__info = True
+        self.__warning = True
+        self.__debug = False
+        self.__logging = False
 
-    def setServerDelta(self, delta, timezone):
+    def setServerDelta(self, delta: float, timezone: int) -> None:
         """
         Call this method on any Notify object to globally change the
         timestamp printed for each line of all Notify objects.
@@ -65,7 +70,7 @@ class Notifier:
 
         self.info("Notify clock adjusted by %s (and timezone adjusted by %s hours) to synchronize with server." % (PythonUtil.formatElapsedSeconds(delta), (time.timezone - timezone) / 3600))
 
-    def getTime(self):
+    def getTime(self) -> str:
         """
         Return the time as a string suitable for printing at the
         head of any notify message
@@ -74,14 +79,14 @@ class Notifier:
         # the task is out of focus on win32.  time.clock doesn't have this problem.
         return time.strftime(":%m-%d-%Y %H:%M:%S ", time.localtime(time.time() + self.serverDelta))
 
-    def getOnlyTime(self):
+    def getOnlyTime(self) -> str:
         """
         Return the time as a string.
         The Only in the name is referring to not showing the date.
         """
         return time.strftime("%H:%M:%S", time.localtime(time.time() + self.serverDelta))
 
-    def __str__(self):
+    def __str__(self) -> str:
         """
         Print handling routine
         """
@@ -89,26 +94,26 @@ class Notifier:
                (self.__name, self.__info, self.__warning, self.__debug, self.__logging)
 
     # Severity funcs
-    def setSeverity(self, severity):
+    def setSeverity(self, severity: int) -> None:
         from panda3d.core import NSDebug, NSInfo, NSWarning, NSError
         if severity >= NSError:
-            self.setWarning(0)
-            self.setInfo(0)
-            self.setDebug(0)
+            self.setWarning(False)
+            self.setInfo(False)
+            self.setDebug(False)
         elif severity == NSWarning:
-            self.setWarning(1)
-            self.setInfo(0)
-            self.setDebug(0)
+            self.setWarning(True)
+            self.setInfo(False)
+            self.setDebug(False)
         elif severity == NSInfo:
-            self.setWarning(1)
-            self.setInfo(1)
-            self.setDebug(0)
+            self.setWarning(True)
+            self.setInfo(True)
+            self.setDebug(False)
         elif severity <= NSDebug:
-            self.setWarning(1)
-            self.setInfo(1)
-            self.setDebug(1)
+            self.setWarning(True)
+            self.setInfo(True)
+            self.setDebug(True)
 
-    def getSeverity(self):
+    def getSeverity(self) -> int:
         from panda3d.core import NSDebug, NSInfo, NSWarning, NSError
         if self.getDebug():
             return NSDebug
@@ -120,7 +125,7 @@ class Notifier:
             return NSError
 
     # error funcs
-    def error(self, errorString, exception=NotifierException):
+    def error(self, errorString: object, exception: type[Exception] = NotifierException) -> NoReturn:
         """
         Raise an exception with given string and optional type:
         Exception: error
@@ -134,7 +139,7 @@ class Notifier:
         raise exception(errorString)
 
     # warning funcs
-    def warning(self, warningString):
+    def warning(self, warningString: object) -> int:
         """
         Issue the warning message if warn flag is on
         """
@@ -148,20 +153,20 @@ class Notifier:
             self.__print(string)
         return 1 # to allow assert myNotify.warning("blah")
 
-    def setWarning(self, enable):
+    def setWarning(self, enable: bool) -> None:
         """
         Enable/Disable the printing of warning messages
         """
         self.__warning = enable
 
-    def getWarning(self):
+    def getWarning(self) -> bool:
         """
         Return whether the printing of warning messages is on or off
         """
         return self.__warning
 
     # debug funcs
-    def debug(self, debugString):
+    def debug(self, debugString: object) -> int:
         """
         Issue the debug message if debug flag is on
         """
@@ -175,20 +180,20 @@ class Notifier:
             self.__print(string)
         return 1 # to allow assert myNotify.debug("blah")
 
-    def setDebug(self, enable):
+    def setDebug(self, enable: bool) -> None:
         """
         Enable/Disable the printing of debug messages
         """
         self.__debug = enable
 
-    def getDebug(self):
+    def getDebug(self) -> bool:
         """
         Return whether the printing of debug messages is on or off
         """
         return self.__debug
 
     # info funcs
-    def info(self, infoString):
+    def info(self, infoString: object) -> int:
         """
         Print the given informational string, if info flag is on
         """
@@ -202,39 +207,39 @@ class Notifier:
             self.__print(string)
         return 1 # to allow assert myNotify.info("blah")
 
-    def getInfo(self):
+    def getInfo(self) -> bool:
         """
         Return whether the printing of info messages is on or off
         """
         return self.__info
 
-    def setInfo(self, enable):
+    def setInfo(self, enable: bool) -> None:
         """
         Enable/Disable informational message  printing
         """
         self.__info = enable
 
     # log funcs
-    def __log(self, logEntry):
+    def __log(self, logEntry: str) -> None:
         """
         Determine whether to send informational message to the logger
         """
         if self.__logging:
             self.__logger.log(logEntry)
 
-    def getLogging(self):
+    def getLogging(self) -> bool:
         """
         Return 1 if logging enabled, 0 otherwise
         """
         return self.__logging
 
-    def setLogging(self, enable):
+    def setLogging(self, enable: bool) -> None:
         """
         Set the logging flag to int (1=on, 0=off)
         """
         self.__logging = enable
 
-    def __print(self, string):
+    def __print(self, string: str) -> None:
         """
         Prints the string to output followed by a newline.
         """
@@ -285,7 +290,7 @@ class Notifier:
             self.__print(string)
         return 1 # to allow assert self.notify.debugStateCall(self)
 
-    def debugCall(self, debugString=''):
+    def debugCall(self, debugString: object = '') -> int:
         """
         If this notify is in debug mode, print the time of the
         call followed by the notifier category and
diff --git a/direct/src/directnotify/RotatingLog.py b/direct/src/directnotify/RotatingLog.py
index 1502ad8994..f73ab4315b 100755
--- a/direct/src/directnotify/RotatingLog.py
+++ b/direct/src/directnotify/RotatingLog.py
@@ -1,5 +1,8 @@
+from __future__ import annotations
+
 import os
 import time
+from typing import Iterable
 
 
 class RotatingLog:
@@ -8,7 +11,12 @@ class RotatingLog:
     to a new file if the prior file is too large or after a time interval.
     """
 
-    def __init__(self, path="./log_file", hourInterval=24, megabyteLimit=1024):
+    def __init__(
+        self,
+        path: str = "./log_file",
+        hourInterval: int | None = 24,
+        megabyteLimit: int | None = 1024,
+    ) -> None:
         """
         Args:
             path: a full or partial path with file name.
@@ -28,33 +36,33 @@ class RotatingLog:
         if megabyteLimit is not None:
             self.sizeLimit = megabyteLimit*1024*1024
 
-    def __del__(self):
+    def __del__(self) -> None:
         self.close()
 
-    def close(self):
+    def close(self) -> None:
         if hasattr(self, "file"):
             self.file.flush()
             self.file.close()
             self.closed = self.file.closed
             del self.file
         else:
-            self.closed = 1
+            self.closed = True
 
-    def shouldRotate(self):
+    def shouldRotate(self) -> bool:
         """
         Returns a bool about whether a new log file should
         be created and written to (while at the same time
         stopping output to the old log file and closing it).
         """
         if not hasattr(self, "file"):
-            return 1
+            return True
         if self.timeLimit is not None and time.time() > self.timeLimit:
-            return 1
+            return True
         if self.sizeLimit is not None and self.file.tell() > self.sizeLimit:
-            return 1
-        return 0
+            return True
+        return False
 
-    def filePath(self):
+    def filePath(self) -> str:
         dateString = time.strftime("%Y_%m_%d_%H", time.localtime())
         for i in range(26):
             limit = self.sizeLimit
@@ -65,7 +73,7 @@ class RotatingLog:
         # Maybe we should clear the self.sizeLimit here... maybe.
         return path
 
-    def rotate(self):
+    def rotate(self) -> None:
         """
         Rotate the log now.  You normally shouldn't need to call this.
         See write().
@@ -88,12 +96,13 @@ class RotatingLog:
             #self.newlines = self.file.newlines # Python 2.3, maybe
 
             if self.timeLimit is not None and time.time() > self.timeLimit:
+                assert self.timeInterval is not None
                 self.timeLimit=time.time()+self.timeInterval
         else:
             # We'll keep writing to the old file, if available.
             print("RotatingLog error: Unable to open new log file \"%s\"." % (path,))
 
-    def write(self, data):
+    def write(self, data: str) -> int | None:
         """
         Write the data to either the current log or a new one,
         depending on the return of shouldRotate() and whether
@@ -105,14 +114,15 @@ class RotatingLog:
             r = self.file.write(data)
             self.file.flush()
             return r
+        return None
 
-    def flush(self):
+    def flush(self) -> None:
         return self.file.flush()
 
-    def fileno(self):
+    def fileno(self) -> int:
         return self.file.fileno()
 
-    def isatty(self):
+    def isatty(self) -> bool:
         return self.file.isatty()
 
     def __next__(self):
@@ -131,14 +141,14 @@ class RotatingLog:
     def xreadlines(self):
         return self.file.xreadlines()
 
-    def seek(self, offset, whence=0):
+    def seek(self, offset: int, whence: int = 0) -> int:
         return self.file.seek(offset, whence)
 
-    def tell(self):
+    def tell(self) -> int:
         return self.file.tell()
 
-    def truncate(self, size):
+    def truncate(self, size: int | None) -> int:
         return self.file.truncate(size)
 
-    def writelines(self, sequence):
+    def writelines(self, sequence: Iterable[str]) -> None:
         return self.file.writelines(sequence)
diff --git a/direct/src/distributed/DistributedCartesianGrid.py b/direct/src/distributed/DistributedCartesianGrid.py
index 88c0af7ce9..39e8b212dd 100755
--- a/direct/src/distributed/DistributedCartesianGrid.py
+++ b/direct/src/distributed/DistributedCartesianGrid.py
@@ -23,7 +23,7 @@ GRID_Z_OFFSET = 0.0
 
 class DistributedCartesianGrid(DistributedNode, CartesianGridBase):
     notify = directNotify.newCategory("DistributedCartesianGrid")
-    notify.setDebug(0)
+    notify.setDebug(False)
 
     VisualizeGrid = ConfigVariableBool("visualize-cartesian-grid", False)
 
diff --git a/tests/directnotify/test_DirectNotify.py b/tests/directnotify/test_DirectNotify.py
new file mode 100644
index 0000000000..c98aeb2646
--- /dev/null
+++ b/tests/directnotify/test_DirectNotify.py
@@ -0,0 +1,57 @@
+import pytest
+from panda3d import core
+from direct.directnotify import DirectNotify, Logger, Notifier
+
+CATEGORY_NAME = 'test'
+
+
+@pytest.fixture
+def notify():
+    notify = DirectNotify.DirectNotify()
+    notify.newCategory(CATEGORY_NAME)
+    return notify
+
+
+def test_categories():
+    notify = DirectNotify.DirectNotify()
+    assert len(notify.getCategories()) == 0
+    assert notify.getCategory(CATEGORY_NAME) is None
+    notifier = notify.newCategory(CATEGORY_NAME, logger=Logger.Logger())
+    assert isinstance(notifier, Notifier.Notifier)
+    assert notify.getCategories() == [CATEGORY_NAME]
+
+
+def test_setDconfigLevels(notify):
+    config = core.ConfigVariableString('notify-level-' + CATEGORY_NAME, '')
+    notifier = notify.getCategory(CATEGORY_NAME)
+    config.value = 'error'
+    notify.setDconfigLevels()
+    assert notifier.getSeverity() == core.NS_error
+    config.value = 'warning'
+    notify.setDconfigLevels()
+    assert notifier.getSeverity() == core.NS_warning
+    config.value = 'info'
+    notify.setDconfigLevels()
+    assert notifier.getSeverity() == core.NS_info
+    config.value = 'debug'
+    notify.setDconfigLevels()
+    assert notifier.getSeverity() == core.NS_debug
+
+
+def test_setVerbose(notify):
+    notifier = notify.getCategory(CATEGORY_NAME)
+    notifier.setWarning(False)
+    notifier.setInfo(False)
+    notifier.setDebug(False)
+    notify.setVerbose()
+    assert notifier.getWarning()
+    assert notifier.getInfo()
+    assert notifier.getDebug()
+
+
+def test_giveNotify(notify):
+    class HasNotify:
+        notify = None
+
+    notify.giveNotify(HasNotify)
+    assert isinstance(HasNotify.notify, Notifier.Notifier)
diff --git a/tests/directnotify/test_Logger.py b/tests/directnotify/test_Logger.py
new file mode 100644
index 0000000000..1f0aa76f94
--- /dev/null
+++ b/tests/directnotify/test_Logger.py
@@ -0,0 +1,21 @@
+import re
+from direct.directnotify import Logger
+
+LOG_TEXT = 'Arbitrary log text'
+
+
+def test_logging(tmp_path):
+    log_filename = str(tmp_path / 'log')
+    logger = Logger.Logger(log_filename)
+
+    assert logger.getTimeStamp()
+    logger.log(LOG_TEXT)
+    logger.setTimeStamp(False)
+    assert not logger.getTimeStamp()
+    logger.log(LOG_TEXT)
+    logger._Logger__closeLogFile()
+
+    log_file, = tmp_path.iterdir()
+    log_text = log_file.read_text()
+    pattern = rf'\d\d:\d\d:\d\d:\d\d: {LOG_TEXT}\n{LOG_TEXT}\n'
+    assert re.match(pattern, log_text)
diff --git a/tests/directnotify/test_Notifier.py b/tests/directnotify/test_Notifier.py
new file mode 100644
index 0000000000..66acc4c5ce
--- /dev/null
+++ b/tests/directnotify/test_Notifier.py
@@ -0,0 +1,87 @@
+import io
+import re
+import time
+import pytest
+from panda3d import core
+from direct.directnotify import Logger, Notifier
+
+NOTIFIER_NAME = 'Test notifier'
+DEBUG_LOG = 'Debug log'
+INFO_LOG = 'Info log'
+WARNING_LOG = 'Warning log'
+ERROR_LOG = 'Error log'
+
+
+@pytest.fixture
+def log_io():
+    return io.StringIO()
+
+
+@pytest.fixture
+def notifier(log_io):
+    logger = Logger.Logger()
+    logger.setTimeStamp(False)
+    logger._Logger__logFile = log_io
+    notifier = Notifier.Notifier(NOTIFIER_NAME, logger)
+    notifier.setLogging(True)
+    return notifier
+
+
+def test_setServerDelta():
+    notifier = Notifier.Notifier(NOTIFIER_NAME)
+    notifier.setServerDelta(4.2, time.timezone)
+    assert Notifier.Notifier.serverDelta == 4
+    Notifier.Notifier.serverDelta = 0
+
+
+def test_logging(notifier, log_io):
+    notifier.setLogging(False)
+    assert not notifier.getLogging()
+    notifier.info(INFO_LOG)
+    assert log_io.getvalue() == ''
+
+    notifier.setLogging(True)
+    assert notifier.getLogging()
+    notifier.info(INFO_LOG)
+    assert log_io.getvalue() == f':{NOTIFIER_NAME}: {INFO_LOG}\n'
+
+
+@pytest.mark.parametrize('severity', (core.NS_debug, core.NS_info, core.NS_warning, core.NS_error))
+def test_severity(severity, notifier, log_io):
+    notifier.setSeverity(severity)
+    assert notifier.getSeverity() == severity
+
+    with pytest.raises(Notifier.NotifierException):
+        notifier.error(ERROR_LOG)
+    warning_return = notifier.warning(WARNING_LOG)
+    info_return = notifier.info(INFO_LOG)
+    debug_return = notifier.debug(DEBUG_LOG)
+    assert warning_return and info_return and debug_return
+
+    expected_logs = [
+        f'{Notifier.NotifierException}: {NOTIFIER_NAME}(error): {ERROR_LOG}',
+        f':{NOTIFIER_NAME}(warning): {WARNING_LOG}',
+        f':{NOTIFIER_NAME}: {INFO_LOG}',
+        f':{NOTIFIER_NAME}(debug): {DEBUG_LOG}',
+    ]
+    del expected_logs[6-severity:]
+    assert log_io.getvalue() == '\n'.join(expected_logs) + '\n'
+
+
+def test_custom_exception(notifier):
+    class CustomException(Exception):
+        pass
+
+    with pytest.raises(CustomException):
+        notifier.error(ERROR_LOG, CustomException)
+
+
+def test_debugCall(notifier, log_io):
+    notifier.setDebug(False)
+    return_value = notifier.debugCall(DEBUG_LOG)
+    assert return_value
+    assert log_io.getvalue() == ''
+    notifier.setDebug(True)
+    notifier.debugCall(DEBUG_LOG)
+    pattern = rf':\d\d:\d\d:\d\d:{NOTIFIER_NAME} "{DEBUG_LOG}" test_debugCall\(.*\)\n'
+    assert re.match(pattern, log_io.getvalue())
diff --git a/tests/directnotify/test_RotatingLog.py b/tests/directnotify/test_RotatingLog.py
new file mode 100644
index 0000000000..5ca66503c5
--- /dev/null
+++ b/tests/directnotify/test_RotatingLog.py
@@ -0,0 +1,45 @@
+import pytest
+from direct.directnotify import RotatingLog
+
+LOG_TEXT = 'Arbitrary log text'
+
+
+@pytest.fixture
+def log_dir(tmp_path):
+    log_dir = tmp_path / 'logs'
+    log_dir.mkdir()
+    return log_dir
+
+
+@pytest.fixture
+def rotating_log(log_dir):
+    log_filename = str(log_dir / 'log')
+    rotating_log = RotatingLog.RotatingLog(log_filename)
+    yield rotating_log
+    rotating_log.close()
+
+
+def test_rotation(rotating_log, log_dir):
+    rotating_log.sizeLimit = -1
+    rotating_log.write('1')
+    rotating_log.write('2')
+    written = [f.read_text() for f in log_dir.iterdir()]
+    assert written == ['1', '2'] or written == ['2', '1']
+
+
+def test_wrapper_methods(rotating_log, log_dir):
+    rotating_log.write('')
+    log_file, = log_dir.iterdir()
+
+    assert rotating_log.fileno() == rotating_log.file.fileno()
+    assert rotating_log.isatty() == rotating_log.file.isatty()
+
+    rotating_log.writelines([LOG_TEXT] * 10)
+    assert not log_file.read_text()
+    rotating_log.flush()
+    assert log_file.read_text() == LOG_TEXT * 10
+
+    assert rotating_log.tell() == len(LOG_TEXT) * 10
+    rotating_log.seek(len(LOG_TEXT))
+    rotating_log.truncate(None)
+    assert log_file.read_text() == LOG_TEXT