Remove Rails <5 code/patches/hacks, bump!

lib/sidekiq/cli.rb

@@ -233,17 +233,8 @@ module Sidekiq
 
       if File.directory?(options[:require])
         require 'rails'
-        if ::Rails::VERSION::MAJOR < 4
+        if ::Rails::VERSION::MAJOR < 5
           raise "Sidekiq no longer supports this version of Rails"
-        elsif ::Rails::VERSION::MAJOR == 4
-          # Painful contortions, see 1791 for discussion
-          # No autoloading, we want to force eager load for everything.
-          require File.expand_path("#{options[:require]}/config/application.rb")
-          ::Rails::Application.initializer "sidekiq.eager_load" do
-            ::Rails.application.config.eager_load = true
-          end
-          require 'sidekiq/rails'
-          require File.expand_path("#{options[:require]}/config/environment.rb")
         else
           require 'sidekiq/rails'
           require File.expand_path("#{options[:require]}/config/environment.rb")

lib/sidekiq/extensions/action_mailer.rb

@@ -19,21 +19,9 @@ module Sidekiq
         # The email method can return nil, which causes ActionMailer to return
         # an undeliverable empty message.
         if msg
-          deliver(msg)
-        else
-          raise "#{target.name}##{method_name} returned an undeliverable mail object"
-        end
-      end
-
-      private
-
-      def deliver(msg)
-        if msg.respond_to?(:deliver_now)
-          # Rails 4.2/5.0
           msg.deliver_now
         else
-          # Rails 3.2/4.0/4.1
-          msg.deliver
+          raise "#{target.name}##{method_name} returned an undeliverable mail object"
         end
       end
     end

lib/sidekiq/middleware/server/active_record.rb

@@ -1,23 +0,0 @@
-# frozen_string_literal: true
-module Sidekiq
-  module Middleware
-    module Server
-      class ActiveRecord
-
-        def initialize
-          # With Rails 5+ we must use the Reloader **always**.
-          # The reloader handles code loading and db connection management.
-          if defined?(::Rails) && ::Rails::VERSION::MAJOR >= 5
-            raise ArgumentError, "Rails 5 no longer needs or uses the ActiveRecord middleware."
-          end
-        end
-
-        def call(*args)
-          yield
-        ensure
-          ::ActiveRecord::Base.clear_active_connections!
-        end
-      end
-    end
-  end
-end

lib/sidekiq/rails.rb

@@ -2,22 +2,6 @@
 
 module Sidekiq
   class Rails < ::Rails::Engine
-    # We need to setup this up before any application configuration which might
-    # change Sidekiq middleware.
-    #
-    # This hook happens after `Rails::Application` is inherited within
-    # config/application.rb and before config is touched, usually within the
-    # class block. Definitely before config/environments/*.rb and
-    # config/initializers/*.rb.
-    config.before_configuration do
-      if ::Rails::VERSION::MAJOR < 5 && defined?(::ActiveRecord)
-        Sidekiq.server_middleware do |chain|
-          require 'sidekiq/middleware/server/active_record'
-          chain.add Sidekiq::Middleware::Server::ActiveRecord
-        end
-      end
-    end
-
     config.after_initialize do
       # This hook happens after all initializers are run, just before returning
       # from config/environment.rb back to sidekiq/cli.rb.
@@ -27,9 +11,7 @@ module Sidekiq
       # None of this matters on the client-side, only within the Sidekiq process itself.
       #
       Sidekiq.configure_server do |_|
-        if ::Rails::VERSION::MAJOR >= 5
-          Sidekiq.options[:reloader] = Sidekiq::Rails::Reloader.new
-        end
+        Sidekiq.options[:reloader] = Sidekiq::Rails::Reloader.new
       end
     end
 
@@ -48,11 +30,5 @@ module Sidekiq
         "#<Sidekiq::Rails::Reloader @app=#{@app.class.name}>"
       end
     end
-  end if defined?(::Rails)
-end
-
-if defined?(::Rails) && ::Rails::VERSION::MAJOR < 4
-  $stderr.puts("**************************************************")
-  $stderr.puts("⛔️ WARNING: Sidekiq server is no longer supported by Rails 3.2 - please ensure your server/workers are updated")
-  $stderr.puts("**************************************************")
+  end
 end

lib/sidekiq/version.rb

@@ -1,4 +1,4 @@
 # frozen_string_literal: true
 module Sidekiq
-  VERSION = "5.2.3"
+  VERSION = "6.0.0"
 end

lib/sidekiq/web.rb

@@ -198,16 +198,3 @@ module Sidekiq
 
   Sidekiq::WebAction.class_eval "def _render\n#{ERB.new(File.read(Web::LAYOUT)).src}\nend"
 end
-
-if defined?(::ActionDispatch::Request::Session) &&
-    !::ActionDispatch::Request::Session.method_defined?(:each)
-  # mperham/sidekiq#2460
-  # Rack apps can't reuse the Rails session store without
-  # this monkeypatch, fixed in Rails 5.
-  class ActionDispatch::Request::Session
-    def each(&block)
-      hash = self.to_hash
-      hash.each(&block)
-    end
-  end
-end