Add ActiveModelSerializers.logger with default null device

test/logger_test.rb

@@ -0,0 +1,19 @@
+require 'test_helper'
+
+class ActiveModelSerializers::LoggerTest < Minitest::Test
+
+  def test_logger_is_set_to_action_controller_logger_when_initializer_runs
+    assert_equal ActiveModelSerializers.logger, ActionController::Base.logger
+  end
+
+  def test_logger_can_be_set
+    original_logger = ActiveModelSerializers.logger
+    logger = Logger.new(STDOUT)
+
+    ActiveModelSerializers.logger = logger
+
+    assert_equal ActiveModelSerializers.logger, logger
+  ensure
+    ActiveModelSerializers.logger = original_logger
+  end
+end