Render of object missing the specified nested include - ruby-on-rails

Question

I am migrating a Rails app from 3.2 to 5.1, and it includes a simple enough model which includes a reference to the product type of the batch,
create_table "batches", :force => true do |t|
t.string "code"
t.integer "product_id"
t.boolean "recalled", :default => false
t.datetime "created_at", :null => false
t.datetime "updated_at", :null => false
end
where, (edited down for clarity)
class Batch < ApplicationRecord
validates_presence_of :product
belongs_to :product
end
I am using will_paginate, so I have the following extract in my model to return a table of records,
def self.search(search, page)
if search
Batch.not_recalled.
where('batches.code LIKE ? OR products.code LIKE ? OR products.name LIKE ?',
"%#{search}%", "%#{search}%", "%#{search}%").
references(:product).
includes(:product).
order(:code).
page(page).per_page(30)
else
Batch.not_recalled.
includes(:product).
order(:code).
page(page).per_page(30)
end
end
And correspondingly, in my controller, I have,
# GET /batches/paginated
def paginated
#batches = Batch.search(params[:search], params[:page])
respond_to do |format|
format.html # paginated.html.erb
format.json { render json: #batches.to_json(include: [:product]) } # note the explicit 'include'
end
end
And in the partial to render the object, I have
<%= product = batch[:product] %> # Try and extract the nested record
<%= puts 'debug' %>
<%= puts batch.inspect %>
<%= puts product.inspect %>
<%= puts 'end debug' %>
<tr role="row" %> >
<td ><%= batch[:code] %></td>
<td><%= product ? product[:duplicate_batch] : 'N/A' %></td>
<td><%= product ? product[:code] : 'N/A' %></td>
<td><%= product ? product[:name] : 'N/A' %></td>
<td><%= link_to 'Show', batch %></td>
</tr>
Now, product is always nil, and the inspect shows the product nested record is NOT included.
I can also examine the JSON, and I can see the included 'product' entry ONLY if I explicitly include it in the format.json line of the controller, as shown above. As there isn't an equivalent syntax to specify the include during the format for the HTML render, I'm not able to render the nested product in HTML.
The really curious thing is I have another very similar model in the same app where this works just fine for HTML too, without an explicit include.
I am aware that ActiveRecord does not load until the last minute, but I am using includes with will_paginate, and I don't see why that would be an issue here. The inspect shows the record, not a ActiveRecord query (I believe).
Two questions:
Why is the nested include not included automatically?
If there's a
good reason for that, how do I specify it to include the product in
the HTML render?
Thanks.

Answer 1

add into model
scope :search, -> (search_param, page) do
includes(:product).
order(:code).
paginate_page(page)
end
Add there also search find part and u should be good
Also i would use activeModelSerializer for serializing objects or
https://github.com/Netflix/fast_jsonapi
Also go rails console
Batch.search(code, 1).to_json(include: [:product]) see whats gets displayed