From b32c2081235d6a3c0f94cc4eb3c026b917ee1e4b Mon Sep 17 00:00:00 2001
From: Ikraam Ghoor <ikraamghoor@gmail.com>
Date: Fri, 26 Jun 2026 07:40:05 +0200
Subject: [PATCH] Eager load variant stock on the products API index

The products API index rendered each variant's stock on hand without
eager loading stock items, so the query count grew with the number of
variants across the listed products.

Eager loading stock items for the master, the variants, and the
variants including master keeps the stock queries constant regardless
of how many products and variants are listed.
---
 api/app/controllers/spree/api/products_controller.rb | 6 ++++--
 api/spec/requests/spree/api/products_spec.rb         | 7 +++++++
 2 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/api/app/controllers/spree/api/products_controller.rb b/api/app/controllers/spree/api/products_controller.rb
index 5477a14015..859eab17e6 100644
--- a/api/app/controllers/spree/api/products_controller.rb
+++ b/api/app/controllers/spree/api/products_controller.rb
@@ -9,10 +9,12 @@ def index
           @products = product_scope.where(id: ids)
         else
           products_includes = [
-            :variants,
             :option_types,
             :product_properties,
-            {classifications: :taxon}
+            {classifications: :taxon},
+            {master: {stock_items: :stock_location}},
+            {variants: {stock_items: :stock_location}},
+            {variants_including_master: {stock_items: :stock_location}}
           ]
           @products = product_scope
             .ransack(params[:q])
diff --git a/api/spec/requests/spree/api/products_spec.rb b/api/spec/requests/spree/api/products_spec.rb
index 8396e5db19..82eb922245 100644
--- a/api/spec/requests/spree/api/products_spec.rb
+++ b/api/spec/requests/spree/api/products_spec.rb
@@ -58,6 +58,13 @@ module Spree::Api
         expect(json_response["per_page"]).to eq(Kaminari.config.default_per_page)
       end
 
+      it "loads stock for every product variant without an N+1" do
+        2.times { create(:variant, product: create(:product)) }
+
+        expect { get spree.api_products_path }
+          .to make_database_queries(matching: /from .spree_stock_items./i, count: 3)
+      end
+
       it "retrieves a list of products by id" do
         get spree.api_products_path, params: {ids: [product.id]}
         expect(json_response["products"].first).to have_attributes(show_attributes)