Small refactor and fix for RuboCop

app/models/gpg_signature.rb

@@ -22,14 +22,11 @@ class GpgSignature < ActiveRecord::Base
   validates :gpg_key_primary_keyid, presence: true
 
   def self.with_key_and_subkeys(gpg_key)
-    return none unless gpg_key
-
-    t = arel_table
-    subkey_ids = gpg_key&.subkeys&.pluck(:id)
+    subkey_ids = gpg_key.subkeys.pluck(:id)
 
     where(
-      t[:gpg_key_id].eq(gpg_key&.id).or(
-        t[:gpg_key_subkey_id].in(subkey_ids)
+      arel_table[:gpg_key_id].eq(gpg_key.id).or(
+        arel_table[:gpg_key_subkey_id].in(subkey_ids)
       )
     )
   end

db/post_migrate/20171005130944_schedule_create_gpg_key_subkeys_from_gpg_keys.rb

@@ -8,11 +8,13 @@ class ScheduleCreateGpgKeySubkeysFromGpgKeys < ActiveRecord::Migration
 
   class GpgKey < ActiveRecord::Base
     self.table_name = 'gpg_keys'
+
+    include EachBatch
   end
 
   def up
-    GpgKey.select(:id).in_batches do |relation|
-      jobs = relation.pluck(:id).map do |id|
+    GpgKey.select(:id).each_batch do |gpg_keys|
+      jobs = gpg_keys.pluck(:id).map do |id|
         ['CreateGpgKeySubkeysFromGpgKeys', [id]]
       end