diff --git a/activerecord/lib/active_record/integration.rb b/activerecord/lib/active_record/integration.rb
index 441237da1eb..32362fa86f7 100644
--- a/activerecord/lib/active_record/integration.rb
+++ b/activerecord/lib/active_record/integration.rb
@@ -110,7 +110,6 @@ module ActiveRecord
       end
     end
 
-
     module ClassMethods
       # Defines your model's +to_param+ method to generate "pretty" URLs
       # using +method_name+, which can be any attribute or method that
diff --git a/activerecord/lib/active_record/tasks/database_tasks.rb b/activerecord/lib/active_record/tasks/database_tasks.rb
index c53dee43d70..ba686fc5627 100644
--- a/activerecord/lib/active_record/tasks/database_tasks.rb
+++ b/activerecord/lib/active_record/tasks/database_tasks.rb
@@ -71,9 +71,9 @@ module ActiveRecord
         @tasks[pattern] = task
       end
 
-      register_task(/mysql/,        'ActiveRecord::Tasks::MySQLDatabaseTasks')
-      register_task(/postgresql/,   'ActiveRecord::Tasks::PostgreSQLDatabaseTasks')
-      register_task(/sqlite/,       'ActiveRecord::Tasks::SQLiteDatabaseTasks')
+      register_task(/mysql/,        "ActiveRecord::Tasks::MySQLDatabaseTasks")
+      register_task(/postgresql/,   "ActiveRecord::Tasks::PostgreSQLDatabaseTasks")
+      register_task(/sqlite/,       "ActiveRecord::Tasks::SQLiteDatabaseTasks")
 
       def db_dir
         @db_dir ||= Rails.application.config.paths["db"].first
diff --git a/activerecord/test/cases/associations/callbacks_test.rb b/activerecord/test/cases/associations/callbacks_test.rb
index 7721bd5cd99..f9d1e445950 100644
--- a/activerecord/test/cases/associations/callbacks_test.rb
+++ b/activerecord/test/cases/associations/callbacks_test.rb
@@ -128,7 +128,7 @@ class AssociationCallbacksTest < ActiveRecord::TestCase
     assert ar.developers_log.empty?
     alice = Developer.new(name: "alice")
     ar.developers_with_callbacks << alice
-    assert_equal"after_adding#{alice.id}", ar.developers_log.last
+    assert_equal "after_adding#{alice.id}", ar.developers_log.last
 
     bob = ar.developers_with_callbacks.create(name: "bob")
     assert_equal "after_adding#{bob.id}", ar.developers_log.last
diff --git a/activesupport/lib/active_support/cache.rb b/activesupport/lib/active_support/cache.rb
index 44f80dd379a..a1093a2e231 100644
--- a/activesupport/lib/active_support/cache.rb
+++ b/activesupport/lib/active_support/cache.rb
@@ -536,7 +536,6 @@ module ActiveSupport
           end
         end
 
-
         # Prefixes a key with the namespace. Namespace and key will be delimited
         # with a colon.
         def normalize_key(key, options)
@@ -587,7 +586,6 @@ module ActiveSupport
           ActiveSupport::Notifications.instrument("cache_#{operation}.active_support", payload) { yield(payload) }
         end
 
-
         def log
           return unless logger && logger.debug? && !silence?
           logger.debug(yield)