User may have many WebhookEndpoints [migration]

Although we won't be allowing multiple in the this PR, we certainly plan to in the future.

The migration helper add_reference couldn't handle the custom column name, so I had to put it together manually.

app/models/spree/user.rb

@@ -38,6 +38,8 @@ module Spree
     has_many :customers
     has_many :credit_cards
     has_many :report_rendering_options, class_name: "::ReportRenderingOptions", dependent: :destroy
+    has_many :webhook_endpoints, dependent: :destroy
+
     accepts_nested_attributes_for :enterprise_roles, allow_destroy: true
 
     accepts_nested_attributes_for :bill_address

db/migrate/20221028053214_add_spree_user_reference_to_webhook_endpoint.rb

@@ -0,0 +1,9 @@
+# frozen_string_literal: true
+
+class AddSpreeUserReferenceToWebhookEndpoint < ActiveRecord::Migration[6.1]
+  def change
+    add_column :webhook_endpoints, :user_id, :bigint, default: 0, null: false
+    add_index :webhook_endpoints, :user_id
+    add_foreign_key :webhook_endpoints, :spree_users, column: :user_id
+  end
+end

db/schema.rb

@@ -1193,6 +1193,8 @@ ActiveRecord::Schema.define(version: 2023_02_13_160135) do
     t.string "url", null: false
     t.datetime "created_at", precision: 6, null: false
     t.datetime "updated_at", precision: 6, null: false
+    t.bigint "user_id", default: 0, null: false
+    t.index ["user_id"], name: "index_webhook_endpoints_on_user_id"
   end
 
   add_foreign_key "active_storage_attachments", "active_storage_blobs", column: "blob_id"
@@ -1299,4 +1301,5 @@ ActiveRecord::Schema.define(version: 2023_02_13_160135) do
   add_foreign_key "subscriptions", "spree_shipping_methods", column: "shipping_method_id", name: "subscriptions_shipping_method_id_fk"
   add_foreign_key "variant_overrides", "enterprises", column: "hub_id", name: "variant_overrides_hub_id_fk"
   add_foreign_key "variant_overrides", "spree_variants", column: "variant_id", name: "variant_overrides_variant_id_fk"
+  add_foreign_key "webhook_endpoints", "spree_users", column: "user_id"
 end

spec/models/spree/user_spec.rb

@@ -7,6 +7,7 @@ describe Spree::User do
 
   describe "associations" do
     it { is_expected.to have_many(:owned_enterprises) }
+    it { is_expected.to have_many(:webhook_endpoints).dependent(:destroy) }
 
     describe "addresses" do
       let(:user) { create(:user, bill_address: create(:address)) }