Enable plugins automatically during registration

Previously the --select was only ever populated to E,F,W,C and so
plugins would not be reported when not off-by-default. This adds a
tiny shim so that we enable plugins that are not off-by-default and
:x
:x

1 files changed, 11 insertions, 0 deletions

diff --git a/src/flake8/plugins/manager.py b/src/flake8/plugins/manager.py
index d08d542..697b35f 100644
--- a/src/flake8/plugins/manager.py
+++ b/src/flake8/plugins/manager.py
@@ -161,6 +161,7 @@ class Plugin(object):
     def enable(self, optmanager):
         """Remove plugin name from the default ignore list."""
         optmanager.remove_from_default_ignore([self.name])
+        optmanager.extend_default_select([self.name])
 
     def disable(self, optmanager):
         """Add the plugin name to the default ignore list."""
@@ -418,6 +419,16 @@ class Checkers(PluginTypeManager):
             if argument_name == plugin.parameters[0]:
                 yield plugin
 
+    def register_options(self, optmanager):
+        """Register all of the checkers' options to the OptionManager."""
+        super(Checkers, self).register_options(optmanager)
+
+        def conditionally_enable(plugin):
+            if plugin.group() is None and not plugin.off_by_default:
+                plugin.enable(optmanager)
+
+        list(self.manager.map(conditionally_enable))
+
     @property
     def ast_plugins(self):
         """List of plugins that expect the AST tree."""