[core] Log parameter that were not used after each draw

Whenever a new bar is being drawn, log out all parameters that were not
used at all. This might indicate a bug in the module, or might point to
a spelling error in the parameter name.

fixes #494

bumblebee/output.py

@@ -5,10 +5,13 @@
 import sys
 import json
 import uuid
+import logging
 
 import bumblebee.store
 import bumblebee.util
 
+log = logging.getLogger(__name__)
+
 def scrollable(func):
     def wrapper(module, widget):
         text = func(module, widget)
@@ -178,6 +181,9 @@ class I3BarOutput(object):
         if self._config and self._config.reverse():
             widgets = list(reversed(widgets))
         sys.stdout.write(json.dumps(widgets))
+        if len(self._config.unused_keys()) > 0:
+            for key in self._config.unused_keys():
+                log.warning("unused parameter {} - please check the documentation of the affected module to ensure the parameter exists".format(key))
 
     def end(self):
         """Finalizes output"""

bumblebee/store.py

@@ -9,13 +9,19 @@ class Store(object):
     """Interface for storing and retrieving simple values"""
     def __init__(self):
         self._data = {}
+        self._unused = {}
 
     def set(self, key, value):
         """Set 'key' to 'value', overwriting 'key' if it exists already"""
         self._data[key] = value
+        self._unused[key] = value
+
+    def unused_keys(self):
+        return self._unused.keys()
 
     def get(self, key, default=None):
         """Return the current value of 'key', or 'default' if 'key' is not set"""
+        self._unused.pop(key, None)
         return self._data.get(key, default)
 
 # vim: tabstop=8 expandtab shiftwidth=4 softtabstop=4