dotbot/controller: check the debug level under any structlog logger

structlog's stdlib BoundLogger only gained is_enabled_for in 26.1, so on
the declared floor every received frame raised and was dropped; its
native filtering logger has no isEnabledFor, and before 25.1 no check at
all. debug_enabled accepts all three.

AI-assisted: Claude Opus 5.5

Author: geonnave

dotbot/controller.py

@@ -9,7 +9,6 @@
 
 import asyncio
 import dataclasses
-import logging
 import math
 import os
 import random
@@ -58,7 +57,7 @@
     CSVLog,
     camera_log_path,
 )
-from dotbot.logger import LOGGER
+from dotbot.logger import LOGGER, debug_enabled
 from dotbot.models import (
     DotBotBodyModel,
     DotBotCalibrationSessionModel,
@@ -689,7 +688,7 @@ def handle_received_frame(
             )
             return
         payload = frame.packet.payload
-        debug = self.logger.is_enabled_for(logging.DEBUG)
+        debug = debug_enabled(self.logger)
         dotbot = self.dotbots.get(source)
         if dotbot is None and payload_type not in ADVERTISEMENT_PAYLOAD_TYPES:
             self.logger.debug("Ignoring non advertised dotbot", source=source)

dotbot/logger.py

@@ -95,4 +95,17 @@ def setup_logging(filename, level, handlers):
     logging.config.dictConfig(stdlib_config)
 
 
+def debug_enabled(logger) -> bool:
+    """Whether `logger` emits DEBUG events.
+
+    structlog's stdlib logger spells the check `isEnabledFor`, its native
+    filtering logger `is_enabled_for` (from 25.1), and before that the native
+    logger has neither, in which case this answers True.
+    """
+    is_enabled = getattr(logger, "isEnabledFor", None) or getattr(
+        logger, "is_enabled_for", None
+    )
+    return is_enabled is None or is_enabled(logging.DEBUG)
+
+
 LOGGER = structlog.get_logger("pydotbot")

dotbot/tests/test_controller.py

@@ -922,6 +922,52 @@ async def test_an_advertisement_without_a_heading_clears_the_last_one(controller
     assert dotbot.pose.heading_source == "none"
 
 
+class _StdlibLogger:
+    """structlog's stdlib BoundLogger before 26.1: `isEnabledFor` only."""
+
+    def __init__(self):
+        self.events = []
+
+    def isEnabledFor(self, level):  # pylint:disable=invalid-name
+        return True
+
+    def debug(self, event, **kw):
+        self.events.append(event)
+
+    info = warning = debug
+
+
+class _NativeLogger(_StdlibLogger):
+    """structlog's native filtering logger from 25.1: `is_enabled_for` only."""
+
+    isEnabledFor = None
+
+    def is_enabled_for(self, level):
+        return True
+
+
+class _OldNativeLogger(_StdlibLogger):
+    """structlog's native filtering logger before 25.1: no level check."""
+
+    isEnabledFor = None
+
+
+@pytest.mark.parametrize(
+    "logger_class", [_StdlibLogger, _NativeLogger, _OldNativeLogger]
+)
+@pytest.mark.asyncio
+async def test_a_frame_is_handled_whatever_the_structlog_logger(
+    controller, logger_class
+):
+    """Guards the structlog floor: the level check exists under every logger."""
+    controller.logger = logger_class()
+    controller.handle_received_frame(
+        _advertised(BOT, direction=90, pos_x=1000, pos_y=2000)
+    )
+    assert addr_to_hex(BOT) in controller.dotbots
+    assert "Advertisement Data" in controller.logger.events
+
+
 @pytest.mark.asyncio
 async def test_the_advertisement_debug_log_reports_y(controller):
     with capture_logs() as logs: