Rails 6 requires Ruby 2.3+

.travis.yml

@@ -75,12 +75,6 @@ matrix:
         - memcached
         - redis-server
         - rabbitmq
-    - rvm: 2.3.6
-      env: "GEM=aj:integration"
-      services:
-        - memcached
-        - redis-server
-        - rabbitmq
     - rvm: 2.4.3
       env: "GEM=aj:integration"
       services:

Gemfile

@@ -38,9 +38,6 @@ gem "rubocop", ">= 0.47", require: false
 # https://github.com/guard/rb-inotify/pull/79
 gem "rb-inotify", github: "matthewd/rb-inotify", branch: "close-handling", require: false
 
-# https://github.com/puma/puma/pull/1345
-gem "stopgap_13632", platforms: :mri if RUBY_VERSION == "2.2.8"
-
 group :doc do
   gem "sdoc", "~> 1.0"
   gem "redcarpet", "~> 3.2.3", platforms: :ruby

actioncable/lib/action_cable/connection/base.rb

@@ -136,13 +136,10 @@ def on_close(reason, code) # :nodoc:
         send_async :handle_close
       end
 
-      # TODO Change this to private once we've dropped Ruby 2.2 support.
-      # Workaround for Ruby 2.2 "private attribute?" warning.
-      protected
+      private
         attr_reader :websocket
         attr_reader :message_buffer
 
-      private
         # The request that initiated the WebSocket connection is available here. This gives access to the environment, cookies, etc.
         def request # :doc:
           @request ||= begin

actioncable/lib/action_cable/connection/message_buffer.rb

@@ -30,13 +30,10 @@ def process!
         receive_buffered_messages
       end
 
-      # TODO Change this to private once we've dropped Ruby 2.2 support.
-      # Workaround for Ruby 2.2 "private attribute?" warning.
-      protected
+      private
         attr_reader :connection
         attr_reader :buffered_messages
 
-      private
         def valid?(message)
           message.is_a?(String)
         end

actioncable/lib/action_cable/connection/subscriptions.rb

@@ -63,12 +63,8 @@ def unsubscribe_from_all
         subscriptions.each { |id, channel| remove_subscription(channel) }
       end
 
-      # TODO Change this to private once we've dropped Ruby 2.2 support.
-      # Workaround for Ruby 2.2 "private attribute?" warning.
-      protected
-        attr_reader :connection, :subscriptions
-
       private
+        attr_reader :connection, :subscriptions
         delegate :logger, to: :connection
 
         def find(data)

actioncable/lib/action_cable/connection/web_socket.rb

@@ -34,9 +34,7 @@ def rack_response
         websocket.rack_response
       end
 
-      # TODO Change this to private once we've dropped Ruby 2.2 support.
-      # Workaround for Ruby 2.2 "private attribute?" warning.
-      protected
+      private
         attr_reader :websocket
     end
   end

actionpack/lib/action_dispatch/http/mime_type.rb

@@ -279,13 +279,8 @@ def html?
 
     def all?; false; end
 
-    # TODO Change this to private once we've dropped Ruby 2.2 support.
-    # Workaround for Ruby 2.2 "private attribute?" warning.
-    protected
-
-      attr_reader :string, :synonyms
-
     private
+      attr_reader :string, :synonyms
 
       def to_ary; end
       def to_a; end

actionpack/test/controller/parameters/accessors_test.rb

@@ -273,23 +273,16 @@ class ParametersAccessorsTest < ActiveSupport::TestCase
     assert_match(/permitted: true/, @params.inspect)
   end
 
-  if Hash.method_defined?(:dig)
-    test "#dig delegates the dig method to its values" do
-      assert_equal "David", @params.dig(:person, :name, :first)
-      assert_equal "Chicago", @params.dig(:person, :addresses, 0, :city)
-    end
+  test "#dig delegates the dig method to its values" do
+    assert_equal "David", @params.dig(:person, :name, :first)
+    assert_equal "Chicago", @params.dig(:person, :addresses, 0, :city)
+  end
 
-    test "#dig converts hashes to parameters" do
-      assert_kind_of ActionController::Parameters, @params.dig(:person)
-      assert_kind_of ActionController::Parameters, @params.dig(:person, :addresses, 0)
-      assert @params.dig(:person, :addresses).all? do |value|
-        value.is_a?(ActionController::Parameters)
-      end
-    end
-  else
-    test "ActionController::Parameters does not respond to #dig on Ruby 2.2" do
-      assert_not ActionController::Parameters.method_defined?(:dig)
-      assert_not_respond_to @params, :dig
+  test "#dig converts hashes to parameters" do
+    assert_kind_of ActionController::Parameters, @params.dig(:person)
+    assert_kind_of ActionController::Parameters, @params.dig(:person, :addresses, 0)
+    assert @params.dig(:person, :addresses).all? do |value|
+      value.is_a?(ActionController::Parameters)
     end
   end
 end

actionview/lib/action_view/helpers/tags/translator.rb

@@ -16,13 +16,8 @@ def translate
           translated_attribute || human_attribute_name
         end
 
-        # TODO Change this to private once we've dropped Ruby 2.2 support.
-        # Workaround for Ruby 2.2 "private attribute?" warning.
-        protected
-
-          attr_reader :object_name, :method_and_value, :scope, :model
-
         private
+          attr_reader :object_name, :method_and_value, :scope, :model
 
           def i18n_default
             if model

activemodel/lib/active_model/attribute_mutation_tracker.rb

@@ -69,13 +69,8 @@ def force_change(attr_name)
       forced_changes << attr_name.to_s
     end
 
-    # TODO Change this to private once we've dropped Ruby 2.2 support.
-    # Workaround for Ruby 2.2 "private attribute?" warning.
-    protected
-
-      attr_reader :attributes, :forced_changes
-
     private
+      attr_reader :attributes, :forced_changes
 
       def attr_names
         attributes.keys

activemodel/lib/active_model/type/integer.rb

@@ -31,13 +31,8 @@ def serialize(value)
         result
       end
 
-      # TODO Change this to private once we've dropped Ruby 2.2 support.
-      # Workaround for Ruby 2.2 "private attribute?" warning.
-      protected
-
-        attr_reader :range
-
       private
+        attr_reader :range
 
         def cast_value(value)
           case value

activemodel/lib/active_model/type/registry.rb

@@ -23,13 +23,8 @@ def lookup(symbol, *args)
         end
       end
 
-      # TODO Change this to private once we've dropped Ruby 2.2 support.
-      # Workaround for Ruby 2.2 "private attribute?" warning.
-      protected
-
-        attr_reader :registrations
-
       private
+        attr_reader :registrations
 
         def registration_klass
           Registration
@@ -59,10 +54,7 @@ def matches?(type_name, *args, **kwargs)
         type_name == name
       end
 
-      # TODO Change this to private once we've dropped Ruby 2.2 support.
-      # Workaround for Ruby 2.2 "private attribute?" warning.
-      protected
-
+      private
         attr_reader :name, :block
     end
   end

activemodel/lib/active_model/validations/acceptance.rb

@@ -58,13 +58,8 @@ def define_on(klass)
             klass.send(:attr_writer, *attr_writers)
           end
 
-          # TODO Change this to private once we've dropped Ruby 2.2 support.
-          # Workaround for Ruby 2.2 "private attribute?" warning.
-          protected
-
-            attr_reader :attributes
-
           private
+            attr_reader :attributes
 
             def convert_to_reader_name(method_name)
               method_name.to_s.chomp("=")

activemodel/lib/active_model/validations/clusivity.rb

@@ -32,7 +32,7 @@ def delimiter
         @delimiter ||= options[:in] || options[:within]
       end
 
-      # In Ruby 2.2 <tt>Range#include?</tt> on non-number-or-time-ish ranges checks all
+      # After Ruby 2.2, <tt>Range#include?</tt> on non-number-or-time-ish ranges checks all
       # possible values in the range for equality, which is slower but more accurate.
       # <tt>Range#cover?</tt> uses the previous logic of comparing a value with the range
       # endpoints, which is fast but is only accurate on Numeric, Time, Date,

activemodel/test/cases/attribute_assignment_test.rb

@@ -18,10 +18,7 @@ def broken_attribute=(value)
       raise ErrorFromAttributeWriter
     end
 
-    # TODO Change this to private once we've dropped Ruby 2.2 support.
-    # Workaround for Ruby 2.2 "private attribute?" warning.
-    protected
-
+    private
       attr_writer :metadata
   end
 

activerecord/lib/active_record/associations/association_scope.rb

@@ -46,13 +46,9 @@ def self.get_bind_values(owner, chain)
         binds
       end
 
-      # TODO Change this to private once we've dropped Ruby 2.2 support.
-      # Workaround for Ruby 2.2 "private attribute?" warning.
-      protected
-
+      private
         attr_reader :value_transformation
 
-      private
         def join(table, constraint)
           table.create_join(table, table.create_on(constraint))
         end

activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb

@@ -151,13 +151,8 @@ def add_to(table)
         end
       end
 
-      # TODO Change this to private once we've dropped Ruby 2.2 support.
-      # Workaround for Ruby 2.2 "private attribute?" warning.
-      protected
-
-        attr_reader :name, :polymorphic, :index, :foreign_key, :type, :options
-
       private
+        attr_reader :name, :polymorphic, :index, :foreign_key, :type, :options
 
         def as_options(value)
           value.is_a?(Hash) ? value : {}

activerecord/lib/active_record/connection_adapters/postgresql/oid/bit.rb

@@ -43,10 +43,7 @@ def hex?
               /\A[0-9A-F]*\Z/i.match?(value)
             end
 
-            # TODO Change this to private once we've dropped Ruby 2.2 support.
-            # Workaround for Ruby 2.2 "private attribute?" warning.
-            protected
-
+            private
               attr_reader :value
           end
         end

activerecord/lib/active_record/enum.rb

@@ -141,10 +141,7 @@ def assert_valid_value(value)
         end
       end
 
-      # TODO Change this to private once we've dropped Ruby 2.2 support.
-      # Workaround for Ruby 2.2 "private attribute?" warning.
-      protected
-
+      private
         attr_reader :name, :mapping, :subtype
     end
 

activerecord/lib/active_record/railties/controller_runtime.rb

@@ -8,49 +8,44 @@ module Railties # :nodoc:
     module ControllerRuntime #:nodoc:
       extend ActiveSupport::Concern
 
-    # TODO Change this to private once we've dropped Ruby 2.2 support.
-    # Workaround for Ruby 2.2 "private attribute?" warning.
-    protected
-
-      attr_internal :db_runtime
-
-    private
-
-      def process_action(action, *args)
-        # We also need to reset the runtime before each action
-        # because of queries in middleware or in cases we are streaming
-        # and it won't be cleaned up by the method below.
-        ActiveRecord::LogSubscriber.reset_runtime
-        super
+      module ClassMethods # :nodoc:
+        def log_process_action(payload)
+          messages, db_runtime = super, payload[:db_runtime]
+          messages << ("ActiveRecord: %.1fms" % db_runtime.to_f) if db_runtime
+          messages
+        end
       end
 
-      def cleanup_view_runtime
-        if logger && logger.info? && ActiveRecord::Base.connected?
-          db_rt_before_render = ActiveRecord::LogSubscriber.reset_runtime
-          self.db_runtime = (db_runtime || 0) + db_rt_before_render
-          runtime = super
-          db_rt_after_render = ActiveRecord::LogSubscriber.reset_runtime
-          self.db_runtime += db_rt_after_render
-          runtime - db_rt_after_render
-        else
+      private
+        attr_internal :db_runtime
+
+        def process_action(action, *args)
+          # We also need to reset the runtime before each action
+          # because of queries in middleware or in cases we are streaming
+          # and it won't be cleaned up by the method below.
+          ActiveRecord::LogSubscriber.reset_runtime
           super
         end
-      end
 
-      def append_info_to_payload(payload)
-        super
-        if ActiveRecord::Base.connected?
-          payload[:db_runtime] = (db_runtime || 0) + ActiveRecord::LogSubscriber.reset_runtime
+        def cleanup_view_runtime
+          if logger && logger.info? && ActiveRecord::Base.connected?
+            db_rt_before_render = ActiveRecord::LogSubscriber.reset_runtime
+            self.db_runtime = (db_runtime || 0) + db_rt_before_render
+            runtime = super
+            db_rt_after_render = ActiveRecord::LogSubscriber.reset_runtime
+            self.db_runtime += db_rt_after_render
+            runtime - db_rt_after_render
+          else
+            super
+          end
         end
-      end
 
-      module ClassMethods # :nodoc:
-        def log_process_action(payload)
-          messages, db_runtime = super, payload[:db_runtime]
-          messages << ("ActiveRecord: %.1fms" % db_runtime.to_f) if db_runtime
-          messages
+        def append_info_to_payload(payload)
+          super
+          if ActiveRecord::Base.connected?
+            payload[:db_runtime] = (db_runtime || 0) + ActiveRecord::LogSubscriber.reset_runtime
+          end
         end
-      end
     end
   end
 end

activerecord/lib/active_record/reflection.rb

@@ -962,16 +962,14 @@ def add_as_through(seed)
         collect_join_reflections(seed + [self])
       end
 
-      # TODO Change this to private once we've dropped Ruby 2.2 support.
-      # Workaround for Ruby 2.2 "private attribute?" warning.
       protected
-        attr_reader :delegate_reflection
-
         def actual_source_reflection # FIXME: this is a horrible name
           source_reflection.actual_source_reflection
         end
 
       private
+        attr_reader :delegate_reflection
+
         def collect_join_reflections(seed)
           a = source_reflection.add_as_source seed
           if options[:source_type]