Capture log messages during tests

The log messages help finding problems with failed tests.

radicale/tests/__init__.py

@@ -19,15 +19,25 @@ Tests for Radicale.
 
 """
 
+import logging
 import os
 import sys
 from io import BytesIO
 
 sys.path.insert(0, os.path.dirname(os.path.dirname(__file__)))
 
+logger = logging.getLogger("radicale_test")
+if not logger.hasHandlers():
+    handler = logging.StreamHandler(sys.stderr)
+    handler.setFormatter(logging.Formatter("%(levelname)s: %(message)s"))
+    logger.addHandler(handler)
+logger.setLevel(logging.DEBUG)
+
 
 class BaseTest:
     """Base class for tests."""
+    logger = logger
+
     def request(self, method, path, data=None, **args):
         """Send a request."""
         self.application._status = None