Add support for metafield_namespaces in webhook registration

CHANGELOG.md

@@ -1,6 +1,7 @@
 Unreleased
 ----------
 * Fix `add_webhook` generator to create the webhook jobs under the correct directory[#1748](https://github.com/Shopify/shopify_app/pull/1748)
+* Add support for metafield_namespaces in webhook registration [#1745](https://github.com/Shopify/shopify_app/pull/1745)
 
 21.8.1 (December 6, 2023)
 ----------

docs/shopify_app/webhooks.md

@@ -40,6 +40,20 @@ ShopifyApp.configure do |config|
 end
 ```
 
+If you need to read metafields, you can pass in the `metafield_namespaces` parameter in `config/webhooks`. Note if you are also using the `fields` parameter you will need to add `metafields` into that as well. Shopify documentation on metafields in webhooks can be found [here](https://shopify.dev/docs/api/admin-rest/2023-10/resources/webhook#resource-object).
+
+```ruby
+ShopifyApp.configure do |config|
+  config.webhooks = [
+    {
+      topic: 'orders/create',
+      path: 'webhooks/order_create',
+      metafield_namespaces: ['app-namespace'],
+    },
+  ]
+end
+```
+
 If you'd rather implement your own controller then you'll want to use the [`ShopifyApp::WebhookVerification`](/lib/shopify_app/controller_concerns/webhook_verification.rb) module to verify your webhooks, example:
 
 ```ruby

lib/shopify_app/managers/webhooks_manager.rb

@@ -52,6 +52,7 @@ def add_registrations
             path: webhook_path,
             handler: delivery_method == :http ? webhook_job_klass(webhook_path) : nil,
             fields: attributes[:fields],
+            metafield_namespaces: attributes[:metafield_namespaces],
           )
         end
       end

test/shopify_app/managers/webhooks_manager_test.rb

@@ -22,9 +22,10 @@ class ShopifyApp::WebhooksManagerTest < ActiveSupport::TestCase
       path: "webhooks/orders_updated",
       handler: OrdersUpdatedJob,
       fields: nil,
+      metafield_namespaces: nil,
     }
 
-    ShopifyAPI::Webhooks::Registry.expects(:add_registration).with(expected_hash).once
+    ShopifyAPI::Webhooks::Registry.expects(:add_registration).with(**expected_hash).once
     ShopifyApp.configure do |config|
       config.webhooks = [
         { topic: "orders/updated", path: "webhooks/orders_updated" },
@@ -40,9 +41,10 @@ class ShopifyApp::WebhooksManagerTest < ActiveSupport::TestCase
       path: "/webhooks/orders_updated",
       handler: OrdersUpdatedJob,
       fields: nil,
+      metafield_namespaces: nil,
     }
 
-    ShopifyAPI::Webhooks::Registry.expects(:add_registration).with(expected_hash).once
+    ShopifyAPI::Webhooks::Registry.expects(:add_registration).with(**expected_hash).once
     ShopifyApp.configure do |config|
       config.webhooks = [
         {