Send error notification to owner

app/jobs/backorder_job.rb

@@ -42,6 +42,8 @@ def perform(order, linked_variants)
       payload.add_metadata(:order, order)
       payload.add_metadata(:linked_variants, linked_variants)
     end
+
+    BackorderMailer.backorder_failed(order, linked_variants).deliver_later
   end
 
   def place_backorder(order, linked_variants)

app/mailers/backorder_mailer.rb

@@ -0,0 +1,14 @@
+# frozen_string_literal: true
+
+class BackorderMailer < ApplicationMailer
+  include I18nHelper
+
+  def backorder_failed(order, linked_variants)
+    @order = order
+    @linked_variants = linked_variants
+
+    I18n.with_locale valid_locale(order.distributor.owner) do
+      mail(to: order.distributor.owner.email)
+    end
+  end
+end

app/views/backorder_mailer/backorder_failed.haml

@@ -0,0 +1,16 @@
+%h1= t ".headline"
+
+%p= t ".description"
+
+%p= t ".hints"
+%p= t ".order", number: @order.number
+
+%table
+  %tr
+    %th= t ".stock"
+    %th= t ".product"
+
+  - @linked_variants.each do |variant|
+    %tr
+      %td= variant.on_hand
+      %td= variant.product_and_full_name

config/locales/en.yml

@@ -360,6 +360,22 @@ en:
     report_failed: |
       This report failed. It may be too big to process.
       We will look into it but please let us know if the problem persists.
+  backorder_mailer:
+    backorder_failed:
+      subject: "An automatic backorder failed"
+      headline: "Backordering failed"
+      description: |
+        We tried to place or update a backorder for out-of-stock items but
+        something went wrong. You may have negative stock and need to resolve
+        the issue to order more stock in.
+      hints: |
+        You may need to go to the OIDC settings and reconnect your account.
+        Also check that your supplier's catalog hasn't changed and is still
+        supplying all products you need. And please get in touch with us if
+        you have any questions.
+      order: "Affected order: %{number}"
+      stock: "Stock"
+      product: "Product"
   enterprise_mailer:
     confirmation_instructions:
       subject: "Please confirm the email address for %{enterprise}"

spec/jobs/backorder_job_spec.rb

@@ -54,6 +54,12 @@
         subject.perform(nil, [])
       }.not_to raise_error
     end
+
+    it "notifies owner of errors" do
+      expect {
+        subject.perform(order, [])
+      }.to enqueue_mail(BackorderMailer, :backorder_failed)
+    end
   end
 
   describe "#place_backorder" do

spec/mailers/backorder_mailer_spec.rb

@@ -0,0 +1,20 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe BackorderMailer do
+  let(:order) { create(:completed_order_with_totals) }
+  let(:variants) { order.line_items.map(&:variant) }
+
+  describe "#backorder_failed" do
+    it "notifies the owner" do
+      order.distributor.owner.email = "jane@example.net"
+
+      BackorderMailer.backorder_failed(order, variants).deliver_now
+
+      mail = ActionMailer::Base.deliveries.first
+      expect(mail.to).to eq ["jane@example.net"]
+      expect(mail.subject).to eq "An automatic backorder failed"
+    end
+  end
+end

spec/mailers/previews/backorder_mailer_preview.rb

@@ -0,0 +1,12 @@
+# frozen_string_literal: true
+
+class BackorderMailerPreview < ActionMailer::Preview
+  def backorder_failed
+    order = Spree::Order.complete.last || Spree::Order.last
+
+    BackorderMailer.backorder_failed(
+      order,
+      order.line_items.map(&:variant),
+    )
+  end
+end