Improve logging management for plugins: fixes

Delete the remaining usages of BeetsPlugin.listen().

Since BeetsPlugin.listeners are wrapped by a loglevel-setting function,
we cannot easily check their unicity anymore.
BeetsPlugin._raw_listeners set holds the raw listeners.

Legacy plugins that did not handle enough arguments in their listenings
functions may break: dedicated code is now deleted for it would not work
with the decorated listeners.

Tests got fixed. Some modifications were done empirically: if it passes
then it's okay.

beets/plugins.py

@@ -18,7 +18,6 @@ from __future__ import (division, absolute_import, print_function,
                         unicode_literals)
 
 import traceback
-import inspect
 import re
 from collections import defaultdict
 from functools import wraps
@@ -180,17 +179,21 @@ class BeetsPlugin(object):
         mediafile.MediaFile.add_field(name, descriptor)
         library.Item._media_fields.add(name)
 
+    _raw_listeners = None
     listeners = None
 
     def register_listener(self, event, func):
         """Add a function as a listener for the specified event.
         """
-        func = self._set_log_level(logging.WARNING, func)
+        wrapped_func = self._set_log_level(logging.WARNING, func)
 
-        if self.listeners is None:
-            self.listeners = defaultdict(list)
-        if func not in self.listeners[event]:
-            self.listeners[event].append(func)
+        cls = self.__class__
+        if cls.listeners is None or cls._raw_listeners is None:
+            cls._raw_listeners = defaultdict(list)
+            cls.listeners = defaultdict(list)
+        if func not in cls._raw_listeners[event]:
+            cls._raw_listeners[event].append(func)
+            cls.listeners[event].append(wrapped_func)
 
     template_funcs = None
     template_fields = None
@@ -440,9 +443,7 @@ def send(event, **arguments):
     results = []
     for handler in event_handlers()[event]:
         # Don't break legacy plugins if we want to pass more arguments
-        argspec = inspect.getargspec(handler).args
-        args = dict((k, v) for k, v in arguments.items() if k in argspec)
-        result = handler(**args)
+        result = handler(**arguments)
         if result is not None:
             results.append(result)
     return results

beetsplug/chroma.py

@@ -136,6 +136,7 @@ class AcoustidPlugin(plugins.BeetsPlugin):
 
         if self.config['auto']:
             self.register_listener('import_task_start', self.fingerprint_task)
+        self.register_listener('import_task_apply', apply_acoustid_metadata)
 
     def fingerprint_task(self, task, session):
         return fingerprint_task(self._log, task, session)
@@ -211,7 +212,6 @@ def fingerprint_task(log, task, session):
         acoustid_match(log, item.path)
 
 
-@AcoustidPlugin.listen('import_task_apply')
 def apply_acoustid_metadata(task, session):
     """Apply Acoustid metadata (fingerprint and ID) to the task's items.
     """

beetsplug/fromfilename.py

@@ -140,10 +140,11 @@ def apply_matches(d):
 # Plugin structure and hook into import process.
 
 class FromFilenamePlugin(plugins.BeetsPlugin):
-    pass
+    def __init__(self):
+        super(FromFilenamePlugin, self).__init__()
+        self.register_listener('import_task_start', filename_task)
 
 
-@FromFilenamePlugin.listen('import_task_start')
 def filename_task(task, session):
     """Examine each item in the task to see if we can extract a title
     from the filename. Try to match all filenames to a number of

beetsplug/permissions.py

@@ -37,9 +37,10 @@ class Permissions(BeetsPlugin):
             u'file': 644
         })
 
+        self.register_listener('item_imported', permissions)
+        self.register_listener('album_imported', permissions)
+
 
-@Permissions.listen('item_imported')
-@Permissions.listen('album_imported')
 def permissions(lib, item=None, album=None):
     """Running the permission fixer.
     """

test/test_plugins.py

@@ -35,6 +35,7 @@ class TestHelper(helper.TestHelper):
     def setup_plugin_loader(self):
         # FIXME the mocking code is horrific, but this is the lowest and
         # earliest level of the plugin mechanism we can hook into.
+        self.load_plugins()
         self._plugin_loader_patch = patch('beets.plugins.load_plugins')
         self._plugin_classes = set()
         load_plugins = self._plugin_loader_patch.start()
@@ -95,7 +96,7 @@ class ItemWriteTest(unittest.TestCase, TestHelper):
 
         class EventListenerPlugin(plugins.BeetsPlugin):
             pass
-        self.event_listener_plugin = EventListenerPlugin
+        self.event_listener_plugin = EventListenerPlugin()
         self.register_plugin(EventListenerPlugin)
 
     def tearDown(self):
@@ -298,19 +299,15 @@ class ListenersTest(unittest.TestCase, TestHelper):
                 pass
 
         d = DummyPlugin()
-        self.assertEqual(DummyPlugin.listeners['cli_exit'], [d.dummy])
+        self.assertEqual(DummyPlugin._raw_listeners['cli_exit'], [d.dummy])
 
         d2 = DummyPlugin()
-        DummyPlugin.register_listener('cli_exit', d.dummy)
-        self.assertEqual(DummyPlugin.listeners['cli_exit'],
+        self.assertEqual(DummyPlugin._raw_listeners['cli_exit'],
                          [d.dummy, d2.dummy])
 
-        @DummyPlugin.listen('cli_exit')
-        def dummy(lib):
-            pass
-
-        self.assertEqual(DummyPlugin.listeners['cli_exit'],
-                         [d.dummy, d2.dummy, dummy])
+        d.register_listener('cli_exit', d2.dummy)
+        self.assertEqual(DummyPlugin._raw_listeners['cli_exit'],
+                         [d.dummy, d2.dummy])
 
 
 def suite():