[Core] Do not remove components from component registry on shutdown

By removing the components after they shut down, KeyErrors are raised when
trying to acccess the component. Unit tests now clear the component registry
on tear down.

deluge/component.py

@@ -385,13 +385,8 @@ class ComponentRegistry(object):
         :rtype: twisted.internet.defer.Deferred
 
         """
-        def on_success(result, key):
-            del _ComponentRegistry.components[key]
-            return succeed(result)
-
         def on_stopped(result):
-            return DeferredList(map(lambda t: t[1]._component_shutdown().addCallback(on_success, t[0]),
-                                    self.components.items()))
+            return DeferredList(map(lambda c: c._component_shutdown(), self.components.values()))
 
         return self.stop(self.components.keys()).addCallback(on_stopped)
 

deluge/tests/basetest.py

@@ -25,9 +25,9 @@ class BaseTestCase(unittest.TestCase):
         d = maybeDeferred(self.tear_down)
 
         def on_teared_down(result):
-            if len(component._ComponentRegistry.components) != 0:
-                warnings.warn("The component._ComponentRegistry.components is not empty after the test finished!: %s" %
-                              component._ComponentRegistry.components)
+            component._ComponentRegistry.components.clear()
+            component._ComponentRegistry.dependents.clear()
+
         return d.addCallback(on_teared_down)
 
     def set_up(self):

deluge/tests/test_core.py

@@ -69,7 +69,8 @@ class TopLevelResource(Resource):
 
 
 class CoreTestCase(BaseTestCase):
-    def setUp(self):  # NOQA
+
+    def set_up(self):
         common.set_tmp_config_dir()
         self.rpcserver = RPCServer(listen=False)
         self.core = Core()
@@ -94,7 +95,7 @@ class CoreTestCase(BaseTestCase):
             raise error
         return result
 
-    def tearDown(self):  # NOQA
+    def tear_down(self):
 
         def on_shutdown(result):
             del self.rpcserver