Merge branch 'replace-alias_method_chain' into 'master'

Remove the "soon to be deprecated" `alias_method_chain` in favor of `Module#prepend`.

## Are there points in the code the reviewer needs to double check?

Double check whether the behavior of `attr_encrypted_no_db_connection` is still the desired one.

## Why was this MR needed?

The `alias_method_chain` becomes deprecated in Rails 5 in favor of the `Module#prepend` introduced in Ruby 2.0.

This MR prevents future deprecated warnings in light of a possible Rails version bump.

Closes #22302

See merge request !6570

4 files changed, 35 insertions, 30 deletions

diff --git a/CHANGELOG b/CHANGELOG
index 24c5a0409fc..12fcec03514 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -12,6 +12,7 @@ v 8.13.0 (unreleased)
   - Allow the Koding integration to be configured through the API
   - Fix robots.txt disallowing access to groups starting with "s" (Matt Harrison)
   - Use a ConnectionPool for Rails.cache on Sidekiq servers
+  - Replace `alias_method_chain` with `Module#prepend`
   - Only update issuable labels if they have been changed
   - Take filters in account in issuable counters. !6496
   - Revoke button in Applications Settings underlines on hover.
diff --git a/config/initializers/attr_encrypted_no_db_connection.rb b/config/initializers/attr_encrypted_no_db_connection.rb
index c668864089b..e007666b852 100644
--- a/config/initializers/attr_encrypted_no_db_connection.rb
+++ b/config/initializers/attr_encrypted_no_db_connection.rb
@@ -1,20 +1,21 @@
 module AttrEncrypted
   module Adapters
     module ActiveRecord
-      def attribute_instance_methods_as_symbols_with_no_db_connection
-        # Use with_connection so the connection doesn't stay pinned to the thread.
-        connected = ::ActiveRecord::Base.connection_pool.with_connection(&:active?) rescue false
-        
-        if connected
-          # Call version from AttrEncrypted::Adapters::ActiveRecord
-          attribute_instance_methods_as_symbols_without_no_db_connection
-        else
-          # Call version from AttrEncrypted, i.e., `super` with regards to AttrEncrypted::Adapters::ActiveRecord
-          AttrEncrypted.instance_method(:attribute_instance_methods_as_symbols).bind(self).call
+      module DBConnectionQuerier
+        def attribute_instance_methods_as_symbols
+          # Use with_connection so the connection doesn't stay pinned to the thread.
+          connected = ::ActiveRecord::Base.connection_pool.with_connection(&:active?) rescue false
+
+          if connected
+            # Call version from AttrEncrypted::Adapters::ActiveRecord
+            super
+          else
+            # Call version from AttrEncrypted, i.e., `super` with regards to AttrEncrypted::Adapters::ActiveRecord
+            AttrEncrypted.instance_method(:attribute_instance_methods_as_symbols).bind(self).call
+          end
         end
       end
-
-      alias_method_chain :attribute_instance_methods_as_symbols, :no_db_connection
+      prepend DBConnectionQuerier
     end
   end
 end
diff --git a/config/initializers/postgresql_limit_fix.rb b/config/initializers/postgresql_limit_fix.rb
index 0cb3aaf4d24..4224d857e8a 100644
--- a/config/initializers/postgresql_limit_fix.rb
+++ b/config/initializers/postgresql_limit_fix.rb
@@ -1,5 +1,19 @@
 if defined?(ActiveRecord::ConnectionAdapters::PostgreSQLAdapter)
   class ActiveRecord::ConnectionAdapters::PostgreSQLAdapter
+    module LimitFilter
+      def add_column(table_name, column_name, type, options = {})
+        options.delete(:limit) if type == :text
+        super(table_name, column_name, type, options)
+      end
+
+      def change_column(table_name, column_name, type, options = {})
+        options.delete(:limit) if type == :text
+        super(table_name, column_name, type, options)
+      end
+    end
+
+    prepend ActiveRecord::ConnectionAdapters::PostgreSQLAdapter::LimitFilter
+
     class TableDefinition
       def text(*args)
         options = args.extract_options!
@@ -9,18 +23,5 @@ if defined?(ActiveRecord::ConnectionAdapters::PostgreSQLAdapter)
         column_names.each { |name| column(name, type, options) }
       end
     end
-
-    def add_column_with_limit_filter(table_name, column_name, type, options = {})
-      options.delete(:limit) if type == :text
-      add_column_without_limit_filter(table_name, column_name, type, options)
-    end
-
-    def change_column_with_limit_filter(table_name, column_name, type, options = {})
-      options.delete(:limit) if type == :text
-      change_column_without_limit_filter(table_name, column_name, type, options)
-    end
-
-    alias_method_chain :add_column, :limit_filter
-    alias_method_chain :change_column, :limit_filter
   end
 end
diff --git a/lib/banzai/filter/task_list_filter.rb b/lib/banzai/filter/task_list_filter.rb
index 66608c9859c..4efbcaf5c7f 100644
--- a/lib/banzai/filter/task_list_filter.rb
+++ b/lib/banzai/filter/task_list_filter.rb
@@ -10,19 +10,21 @@ module Banzai
     # task_list gem.
     #
     # See https://github.com/github/task_list/pull/60
-    class TaskListFilter < TaskList::Filter
-      def add_css_class_with_fix(node, *new_class_names)
+    module ClassNamesFilter
+      def add_css_class(node, *new_class_names)
         if new_class_names.include?('task-list')
           # Don't add class to all lists
           return
         elsif new_class_names.include?('task-list-item')
-          add_css_class_without_fix(node.parent, 'task-list')
+          super(node.parent, 'task-list')
         end
 
-        add_css_class_without_fix(node, *new_class_names)
+        super(node, *new_class_names)
       end
+    end
 
-      alias_method_chain :add_css_class, :fix
+    class TaskListFilter < TaskList::Filter
+      prepend ClassNamesFilter
     end
   end
 end