Fix wrong sample code about allow_deprecated_singular_associations_name [skip ci]

[willnet]

Summary

The only time #45163 and #45344 have an effect is when the hash value passed to where is a model object. The current sample code does not change behavior between Rails 7.0 and 7.1

[jonathanhefner]

The only time #45163 and #45344 have an effect is when the hash value passed to where is a model object.

Your example is correct, but also applies when passing an ID:

class Post < ActiveRecord::Base
end

class Comment < ActiveRecord::Base
  belongs_to :post
end

ActiveRecord.allow_deprecated_singular_associations_name = false

Comment.where(post: 1).count
# => 3

Comment.where(posts: 1).count
# => no such column: comments.posts (ActiveRecord::StatementInvalid)

ActiveRecord.allow_deprecated_singular_associations_name = true

Comment.where(posts: 1).count
# DEPRECATION WARNING: In Rails 7.2, referring to singular associations by their plural name will be deprecated.
# To continue querying `post` use `posts` instead.
# You can get the new more performant behavior now by setting config.active_record.allow_deprecated_singular_associations_name = false
# => 3

Unless I am misunderstanding, the original example appears to be unaffected by allow_deprecated_singular_associations_name:

class AlsoPost < ActiveRecord::Base
  self.table_name = "posts"
end

class Comment < ActiveRecord::Base
  belongs_to :also_post, foreign_key: "post_id"
end

ActiveRecord.allow_deprecated_singular_associations_name = false

Comment.joins(:post).where(post: { id: 1 }).count
# => 3

Comment.joins(:post).where(posts: { id: 1 }).count
# => 3

Comment.joins(:also_post).where(also_post: { id: 1 }).count
# => 3

Comment.joins(:also_post).where(also_posts: { id: 1 }).count
# => no such column: also_posts.id (ActiveRecord::StatementInvalid)

ActiveRecord.allow_deprecated_singular_associations_name = true

Comment.joins(:also_post).where(also_posts: { id: 1 }).count
# => no such column: also_posts.id (ActiveRecord::StatementInvalid)

[jonathanhefner]

Thank you, @willnet! 👍

[willnet]

@jonathanhefner Thanks, it helps me a lot 😃