Use private attr_reader

Since rails#32028, Rails 6 requires Ruby 2.3+.
No longer needed workaround for Ruby 2.2 "private attribute?" warning.

activerecord/lib/active_record/associations/join_dependency/join_association.rb

@@ -58,7 +58,7 @@ def table
           tables.first
         end
 
-        protected
+        private
           attr_reader :alias_tracker
       end
     end

activerecord/lib/active_record/associations/preloader.rb

@@ -169,7 +169,7 @@ def preloaded_records
             owners.flat_map { |owner| owner.association(reflection.name).target }
           end
 
-          protected
+          private
             attr_reader :owners, :reflection
         end
 

activerecord/lib/active_record/associations/preloader/association.rb

@@ -27,10 +27,9 @@ def run(preloader)
           end
         end
 
-        protected
+        private
           attr_reader :owners, :reflection, :preload_scope, :model, :klass
 
-        private
           # The name of the key on the associated records
           def association_key_name
             reflection.join_primary_key(klass)

activerecord/lib/active_record/attribute_methods.rb

@@ -432,15 +432,12 @@ def accessed_fields
       @attributes.accessed
     end
 
-    protected
-
-      def attribute_method?(attr_name) # :nodoc:
+    private
+      def attribute_method?(attr_name)
         # We check defined? because Syck calls respond_to? before actually calling initialize.
         defined?(@attributes) && @attributes.key?(attr_name)
       end
 
-    private
-
       def arel_attributes_with_values_for_create(attribute_names)
         arel_attributes_with_values(attributes_for_create(attribute_names))
       end

activerecord/lib/active_record/connection_adapters/postgresql/column.rb

@@ -20,10 +20,9 @@ def serial?
         end
       end
 
-      protected
+      private
         attr_reader :max_identifier_length
 
-      private
         def sequence_name_from_parts(table_name, column_name, suffix)
           over_length = [table_name, column_name, suffix].map(&:length).sum + 2 - max_identifier_length
 

activerecord/lib/active_record/relation/predicate_builder.rb

@@ -57,9 +57,6 @@ def build_bind_attribute(column_name, value)
     end
 
     protected
-
-      attr_reader :table
-
       def expand_from_hash(attributes)
         return ["1=0"] if attributes.empty?
 
@@ -109,6 +106,7 @@ def expand_from_hash(attributes)
       end
 
     private
+      attr_reader :table
 
       def associated_predicate_builder(association_name)
         self.class.new(table.associated_table(association_name))

activerecord/lib/active_record/relation/predicate_builder/array_handler.rb

@@ -34,8 +34,7 @@ def call(attribute, value)
         array_predicates.inject(&:or)
       end
 
-      protected
-
+      private
         attr_reader :predicate_builder
 
         module NullPredicate # :nodoc:

activerecord/lib/active_record/relation/predicate_builder/base_handler.rb

@@ -11,8 +11,7 @@ def call(attribute, value)
         predicate_builder.build(attribute, value.id)
       end
 
-      protected
-
+      private
         attr_reader :predicate_builder
     end
   end

activerecord/lib/active_record/relation/predicate_builder/basic_object_handler.rb

@@ -12,8 +12,7 @@ def call(attribute, value)
         attribute.eq(bind)
       end
 
-      protected
-
+      private
         attr_reader :predicate_builder
     end
   end

activerecord/lib/active_record/relation/predicate_builder/range_handler.rb

@@ -33,8 +33,7 @@ def call(attribute, value)
         end
       end
 
-      protected
-
+      private
         attr_reader :predicate_builder
     end
   end

activerecord/lib/active_record/relation/where_clause_factory.rb

@@ -26,8 +26,7 @@ def build(opts, other)
         WhereClause.new(parts)
       end
 
-      protected
-
+      private
         attr_reader :klass, :predicate_builder
     end
   end

activerecord/lib/active_record/statement_cache.rb

@@ -114,8 +114,7 @@ def self.unsupported_value?(value)
       end
     end
 
-    protected
-
+    private
       attr_reader :query_builder, :bind_map, :klass
   end
 end