Ensure pagination is retained when saving or discarding

But we have more work to do.

app/controllers/admin/products_v3_controller.rb

@@ -26,8 +26,8 @@ module Admin
       end
     end
 
-    def index_url
-      "/admin/products" # todo: fix routing so this can be automatically generated
+    def index_url(params)
+      "/admin/products?#{params.to_query}" # todo: fix routing so this can be automaticly generated
     end
 
     private
@@ -43,8 +43,8 @@ module Admin
 
     def init_pagination_params
       # prority is given to element dataset (if present) over url params
-      @page = params[:_page] || 1
-      @per_page = params[:_per_page] || 15
+      @page = params[:_page].presence || 1
+      @per_page = params[:_per_page].presence || 15
     end
 
     def producers

app/views/admin/products_v3/_table.html.haml

@@ -4,6 +4,10 @@
               'bulk-form-error-value': defined?(@error_counts),
               } } do |form|
   = render(partial: "admin/shared/flashes", locals: { flashes: }) if defined? flashes
+
+  = hidden_field_tag :_page, @page
+  = hidden_field_tag :_per_page, @per_page
+
   %table.products
     %colgroup
       %col{ width:"56" }= #  Img (size + padding)
@@ -35,7 +39,6 @@
                         -# Y products could not be saved correctly. Please review errors and try again
                         = t('.error_summary.invalid', count: @error_counts[:invalid])
                 .form-buttons
-
                   %a.button.reset.medium{ href: admin_products_path(page: @page, per_page: @per_page) }
                     = t('.reset')
                   = form.submit t('.save'), class: "medium"

spec/system/admin/products_v3/products_spec.rb

@@ -608,6 +608,37 @@ describe 'As an admin, I can manage products', feature: :admin_style_v3 do
         expect(page).to have_content "Please review the errors and try again"
       end
     end
+
+    context "pagination" do
+      let!(:product_a) { create(:simple_product, name: "zucchini") } # appears on p2
+
+      it "retains selected page after saving" do
+        create_products 15 # in addition to product_a
+        visit admin_products_url
+
+        within ".pagination" do
+          click_link "2"
+        end
+
+        within row_containing_name("zucchini") do
+          fill_in "Name", with: "zucchinis"
+        end
+
+        expect {
+          click_button "Save changes"
+
+          expect(page).to have_content "Changes saved"
+          product_a.reload
+        }.to change { product_a.name }.to("zucchinis")
+
+        pending "awaiting pagination to be loaded without SR"
+        expect(page).to have_content "Showing 16 to 16" # todo: remove unnecessary duplication
+        expect_page_to_be 2
+        expect_per_page_to_be 15
+        expect_products_count_to_be 1
+        expect(page).to have_css row_containing_name("zucchinis")
+      end
+    end
   end
 
   describe "edit image" do