Removed duplicate requiring minitest/mock as it is already required in method_call_assertions

actionmailer/test/message_delivery_test.rb

@@ -1,6 +1,5 @@
 require 'abstract_unit'
 require 'active_job'
-require 'minitest/mock'
 require 'mailers/delayed_mailer'
 
 class MessageDeliveryTest < ActiveSupport::TestCase

actionpack/test/controller/parameters/always_permitted_parameters_test.rb

@@ -1,6 +1,5 @@
 require 'abstract_unit'
 require 'action_controller/metal/strong_parameters'
-require 'minitest/mock'
 
 class AlwaysPermittedParametersTest < ActiveSupport::TestCase
   def setup

activemodel/test/cases/helper.rb

@@ -13,8 +13,6 @@ I18n.enforce_available_locales = false
 require 'active_support/testing/autorun'
 require 'active_support/testing/method_call_assertions'
 
-require 'minitest/mock'
-
 # Skips the current run on Rubinius using Minitest::Assertions#skip
 def rubinius_skip(message = '')
   skip message if RUBY_ENGINE == 'rbx'

activesupport/test/abstract_unit.rb

@@ -38,8 +38,6 @@ def jruby_skip(message = '')
   skip message if defined?(JRUBY_VERSION)
 end
 
-require 'minitest/mock'
-
 class ActiveSupport::TestCase
   include ActiveSupport::Testing::MethodCallAssertions
 end

railties/test/generators/named_base_test.rb

@@ -1,6 +1,5 @@
 require 'generators/generators_test_helper'
 require 'rails/generators/rails/scaffold_controller/scaffold_controller_generator'
-require 'minitest/mock'
 
 class NamedBaseTest < Rails::Generators::TestCase
   include GeneratorsTestHelper