We don't need a support from ActiveSupport for this simple configuration storage

kaminari-core/lib/kaminari/config.rb

@@ -1,28 +1,40 @@
 # frozen_string_literal: true
-require 'active_support/configurable'
 
 module Kaminari
   # Configures global settings for Kaminari
   #   Kaminari.configure do |config|
   #     config.default_per_page = 10
   #   end
-  include ActiveSupport::Configurable
+  class << self
+    def configure
+      yield config
+    end
 
-  config.instance_eval do
-    self.default_per_page = 25
-    self.max_per_page = nil
-    self.window = 4
-    self.outer_window = 0
-    self.left = 0
-    self.right = 0
-    self.page_method_name = :page
-    self.param_name = :page
-    self.max_pages = nil
-    self.params_on_first_page = false
+    def config
+      @_config ||= Config.new
+    end
+  end
+
+  class Config
+    attr_accessor :default_per_page, :max_per_page, :window, :outer_window, :left, :right, :page_method_name, :max_pages, :params_on_first_page
+    attr_writer :param_name
+
+    def initialize
+      @default_per_page = 25
+      @max_per_page = nil
+      @window = 4
+      @outer_window = 0
+      @left = 0
+      @right = 0
+      @page_method_name = :page
+      @param_name = :page
+      @max_pages = nil
+      @params_on_first_page = false
+    end
 
     # If param_name was given as a callable object, call it when returning
     def param_name
-      self[:param_name].respond_to?(:call) ? self[:param_name].call : self[:param_name]
+      @param_name.respond_to?(:call) ? @param_name.call : @param_name
     end
   end
 end