Add missing docstrings.

qutebrowser/test/utils/test_debug.py

@@ -156,6 +156,7 @@ class TestLogTime(unittest.TestCase):
     """Test log_time."""
 
     def test_log_time(self):
+        """Test if log_time logs properly."""
         logger = logging.getLogger('qt-tests')
         with self.assertLogs(logger, logging.DEBUG) as logged:
             with debug.log_time(logger, action='foobar'):

qutebrowser/utils/debug.py

@@ -254,6 +254,12 @@ def format_call(func, args=None, kwargs=None, full=True):
 
 @contextlib.contextmanager
 def log_time(logger, action='operation'):
+    """Log the time the operation in the with-block takes.
+
+    Args:
+        logger: The logging.Logger to use for logging.
+        action: A description of what's being done.
+    """
     started = datetime.datetime.now()
     yield
     finished = datetime.datetime.now()