Allow object_id as a column name for ActiveRecord

Fixes rails#50160

The `object_id` name may be used by polymorphic relations where `object` is the best name, like `notification.object`.
In that case two columns are created: `object_id` and `object_type`.

Update tests and comments to reference `__id__` instead of `object_id` for consistency.

activerecord/CHANGELOG.md

@@ -1,20 +1,25 @@
-*   In cases where MySQL returns `warning_count` greater than zero, but returns no warnings when
+* Allow using `object_id` as a database column name.
+    It was available before rails 7.1 and may be used as a part of polymorphic relationship to `object` where `object` can be any other database record.
+
+    *Mikhail Doronin*
+
+* In cases where MySQL returns `warning_count` greater than zero, but returns no warnings when
     the `SHOW WARNINGS` query is executed, `ActiveRecord.db_warnings_action` proc will still be
     called with a generic warning message rather than silently ignoring the warning(s).
 
     *Kevin McPhillips*
 
-*   `DatabaseConfigurations#configs_for` can accept a symbol in the `name` parameter.
+* `DatabaseConfigurations#configs_for` can accept a symbol in the `name` parameter.
 
     *Andrew Novoselac*
 
-*   Fix `where(field: values)` queries when `field` is a serialized attribute
+* Fix `where(field: values)` queries when `field` is a serialized attribute
     (for example, when `field` uses `ActiveRecord::Base.serialize` or is a JSON
     column).
 
     *João Alves*
 
-*   Make the output of `ActiveRecord::Core#inspect` configurable.
+* Make the output of `ActiveRecord::Core#inspect` configurable.
 
     By default, calling `inspect` on a record will yield a formatted string including just the `id`.
 
@@ -45,17 +50,17 @@
 
     *Andrew Novoselac*
 
-*   Don't mark Float::INFINITY as changed when reassigning it
+* Don't mark Float::INFINITY as changed when reassigning it
 
     When saving a record with a float infinite value, it shouldn't mark as changed
 
     *Maicol Bentancor*
 
-*   Support `RETURNING` clause for MariaDB
+* Support `RETURNING` clause for MariaDB
 
     *fatkodima*, *Nikolay Kondratyev*
 
-*   The SQLite3 adapter now implements the `supports_deferrable_constraints?` contract
+* The SQLite3 adapter now implements the `supports_deferrable_constraints?` contract
 
     Allows foreign keys to be deferred by adding the `:deferrable` key to the `foreign_key` options.
 
@@ -66,7 +71,7 @@
 
     *Stephen Margheim*
 
-*   Add `set_constraints` helper for PostgreSQL
+* Add `set_constraints` helper for PostgreSQL
 
     ```ruby
     Post.create!(user_id: -1) # => ActiveRecord::InvalidForeignKey
@@ -82,11 +87,11 @@
 
     *Cody Cutrer*
 
-*   Include `ActiveModel::API` in `ActiveRecord::Base`
+* Include `ActiveModel::API` in `ActiveRecord::Base`
 
     *Sean Doyle*
 
-*   Ensure `#signed_id` outputs `url_safe` strings.
+* Ensure `#signed_id` outputs `url_safe` strings.
 
     *Jason Meller*
 

activerecord/lib/active_record/associations.rb

@@ -1163,7 +1163,7 @@ def association_instance_set(name, association)
       #
       #    d = Dungeon.first
       #    t = d.traps.first
-      #    d.object_id == t.dungeon.object_id # => true
+      #    d.__id__ == t.dungeon.__id__ # => true
       #
       # The +Dungeon+ instances +d+ and <tt>t.dungeon</tt> in the above example refer to
       # the same in-memory instance since the association matches the name of the class.

activerecord/lib/active_record/attribute_methods.rb

@@ -33,7 +33,7 @@ def dangerous_attribute_methods # :nodoc:
           Base.private_instance_methods -
           Base.superclass.instance_methods -
           Base.superclass.private_instance_methods +
-          %i[__id__ dup freeze frozen? hash object_id class clone]
+          %i[__id__ dup freeze frozen? hash class clone]
         ).map { |m| -m.to_s }.to_set.freeze
       end
     end

activerecord/lib/active_record/core.rb

@@ -488,10 +488,10 @@ def init_with_attributes(attributes, new_record = false) # :nodoc:
     #   new_user.name = "Joe"
     #   user.name               # => "Joe"
     #
-    #   user.object_id == new_user.object_id            # => false
-    #   user.name.object_id == new_user.name.object_id  # => true
+    #   user.__id__ == new_user.__id__            # => false
+    #   user.name.__id__ == new_user.name.__id__  # => true
     #
-    #   user.name.object_id == user.dup.name.object_id  # => false
+    #   user.name.__id__ == user.dup.name.__id__  # => false
 
     ##
     # :method: dup

activerecord/test/cases/associations_test.rb

@@ -1261,7 +1261,7 @@ def test_preload_with_available_records_with_through_association
     end
 
     assert_predicate author.association(:essay_category), :loaded?
-    assert categories.map(&:object_id).include?(author.essay_category.object_id)
+    assert categories.map(&:__id__).include?(author.essay_category.__id__)
   end
 
   def test_preload_with_only_some_records_available_with_through_associations
@@ -1307,7 +1307,7 @@ def test_preload_with_available_records_queries_when_scoped
     end
 
     assert_predicate post.association(:author), :loaded?
-    assert_not_equal david.object_id, post.author.object_id
+    assert_not_equal david.__id__, post.author.__id__
   end
 
   def test_preload_with_available_records_queries_when_collection
@@ -1319,7 +1319,7 @@ def test_preload_with_available_records_queries_when_collection
     end
 
     assert_predicate post.association(:comments), :loaded?
-    assert_empty post.comments.map(&:object_id) & comments.map(&:object_id)
+    assert_empty post.comments.map(&:__id__) & comments.map(&:__id__)
   end
 
   def test_preload_with_available_records_queries_when_incomplete