Extract mergeAllWebhooks transform from Zod schema into breakdown-extensions

Remove the parse-time mergeAllWebhooks transform from WebhooksConfigSchema
so that parsed webhook subscriptions preserve their raw TOML form (multi-topic
arrays stay intact). This fixes the round-trip asymmetry where compliance
subscriptions got reordered to the front on re-parse.

The only consumer that needs canonical one-topic-per-subscription form is
breakdown-extensions.ts (for comparing local vs remote config), so the
mergeAllWebhooks normalization is applied there before diffing.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: ryancbahan

packages/app/src/cli/models/app/loader.test.ts

@@ -2172,10 +2172,7 @@ redirect_urls = [ "https://example.com/api/auth" ]
       {
         webhooks: {
           api_version: '2024-01',
-          subscriptions: [
-            {topics: ['orders/create'], uri: 'https://example.com'},
-            {topics: ['orders/delete'], uri: 'https://example.com'},
-          ],
+          subscriptions: [{topics: ['orders/create', 'orders/delete'], uri: 'https://example.com'}],
         },
         name: 'for-testing-webhooks',
       },
@@ -3084,39 +3081,10 @@ describe('WebhooksSchema', () => {
       ],
     }
 
-    const expandedWebhookConfig: WebhooksConfig = {
-      api_version: '2021-07',
-      subscriptions: [
-        {
-          uri: 'arn:aws:events:us-west-2::event-source/aws.partner/shopify.com/1234567890/SOME_PATH',
-          topics: ['products/create'],
-        },
-        {
-          uri: 'arn:aws:events:us-west-2::event-source/aws.partner/shopify.com/1234567890/SOME_PATH',
-          topics: ['products/update'],
-        },
-        {
-          uri: 'https://example.com',
-          topics: ['products/create'],
-        },
-        {
-          uri: 'https://example.com',
-          topics: ['products/update'],
-        },
-        {
-          uri: 'pubsub://my-project-123:my-topic',
-          topics: ['products/create'],
-        },
-        {
-          uri: 'pubsub://my-project-123:my-topic',
-          topics: ['products/update'],
-        },
-      ],
-    }
-
     const {abortOrReport, parsedConfiguration} = await setupParsing({}, webhookConfig)
     expect(abortOrReport).not.toHaveBeenCalled()
-    expect(parsedConfiguration.webhooks).toMatchObject(expandedWebhookConfig)
+    // Without the parse-time mergeAllWebhooks transform, subscriptions preserve their raw multi-topic form
+    expect(parsedConfiguration.webhooks).toMatchObject(webhookConfig)
   })
 
   test('throws an error if we have duplicate subscriptions in same topics array', async () => {

packages/app/src/cli/models/extensions/specifications/app_config_webhook_schemas/webhooks_schema.ts

@@ -2,7 +2,6 @@ import {WebhookSubscriptionSchema} from './webhook_subscription_schema.js'
 import {webhookValidator} from '../validation/app_config_webhook.js'
 import {WebhookSubscriptionUriValidation} from '../validation/common.js'
 import {SingleWebhookSubscriptionSchema} from '../app_config_webhook_subscription.js'
-import {mergeAllWebhooks} from '../transform/app_config_webhook.js'
 import {BaseSchemaWithoutHandle} from '../../schemas.js'
 import {zod} from '@shopify/cli-kit/node/schema'
 
@@ -15,10 +14,7 @@ const WebhooksConfigSchema = zod.object({
       shop_deletion_url: WebhookSubscriptionUriValidation.optional(),
     })
     .optional(),
-  subscriptions: zod
-    .array(WebhookSubscriptionSchema)
-    .optional()
-    .transform((value) => mergeAllWebhooks(value ?? [])),
+  subscriptions: zod.array(WebhookSubscriptionSchema).optional(),
 })
 
 export type SingleWebhookSubscriptionType = zod.infer<typeof SingleWebhookSubscriptionSchema>

packages/app/src/cli/services/app/__snapshots__/config-pipeline-snapshot.test.ts.snap

@@ -1,57 +1,5 @@
 // Vitest Snapshot v1, https://vitest.dev/guide/snapshot.html
 
-exports[`Config pipeline snapshots > config round-trip (write → read → write) reorders webhook subscriptions 1`] = `
-"# Learn more about configuring your app at https://shopify.dev/docs/apps/tools/cli/configuration
-
-client_id = \\"12345\\"
-name = \\"My Test App\\"
-application_url = \\"https://myapp.example.com\\"
-embedded = true
-
-[build]
-automatically_update_urls_on_dev = true
-dev_store_url = \\"test-store.myshopify.com\\"
-include_config_on_deploy = true
-
-[access_scopes]
-# Learn more at https://shopify.dev/docs/apps/tools/cli/configuration#access_scopes
-scopes = \\"read_products,write_orders\\"
-use_legacy_install_flow = false
-
-[auth]
-redirect_urls = [
-  \\"https://myapp.example.com/auth/callback\\",
-  \\"https://myapp.example.com/auth/shopify/callback\\"
-]
-
-[webhooks]
-api_version = \\"2024-01\\"
-
-  [[webhooks.subscriptions]]
-  uri = \\"/webhooks/compliance\\"
-  compliance_topics = [ \\"customers/data_request\\", \\"customers/redact\\" ]
-
-  [[webhooks.subscriptions]]
-  topics = [ \\"orders/create\\" ]
-  uri = \\"/webhooks/orders\\"
-
-  [[webhooks.subscriptions]]
-  topics = [ \\"products/create\\", \\"products/update\\" ]
-  uri = \\"/webhooks/products\\"
-
-[app_proxy]
-url = \\"https://myapp.example.com/proxy\\"
-subpath = \\"app\\"
-prefix = \\"apps\\"
-
-[pos]
-embedded = false
-
-[app_preferences]
-url = \\"https://myapp.example.com/preferences\\"
-"
-`;
-
 exports[`Config pipeline snapshots > minimal config without webhooks produces stable output 1`] = `
 "# Learn more about configuring your app at https://shopify.dev/docs/apps/tools/cli/configuration
 

packages/app/src/cli/services/app/config-pipeline-snapshot.test.ts

@@ -77,30 +77,27 @@ describe('Config pipeline snapshots', () => {
     })
   })
 
-  test('config round-trip (write → read → write) reorders webhook subscriptions', async () => {
-    // KNOWN ASYMMETRY: The current pipeline does NOT round-trip cleanly.
-    // mergeAllWebhooks() sorts compliance subscriptions first during parse,
-    // so the second write has a different subscription order than the first.
-    // This test documents the current behavior as a snapshot.
-    // When the webhook transform is extracted from the schema (Phase 2),
-    // this test should be updated to verify clean round-trips.
+  test('config round-trip (write → read → write) preserves subscription order', async () => {
+    // With the mergeAllWebhooks transform extracted from the Zod schema,
+    // the parse pipeline no longer reorders webhook subscriptions.
+    // This verifies a clean round-trip: first write === second write.
     await inTemporaryDirectory(async (tmp) => {
       const filePath = joinPath(tmp, 'shopify.app.toml')
       const {schema, configSpecifications: specs} = await buildVersionedAppSchema()
 
       // First write
       await writeAppConfigurationFile(REALISTIC_CONFIG as CurrentAppConfiguration, schema, filePath)
+      const firstWrite = await readFile(filePath)
 
-      // Read back through the full parse pipeline (which fires Zod transforms)
+      // Read back through the full parse pipeline (no more Zod transforms on webhooks)
       const parsedConfig = await parseConfigurationFile(getAppVersionedSchema(specs), filePath)
 
-      // Second write from the parsed (transformed) config
+      // Second write from the parsed config
       await writeAppConfigurationFile(parsedConfig, schema, filePath)
       const secondWrite = await readFile(filePath)
 
-      // Snapshot the round-tripped output — it differs from the first write
-      // because compliance subscriptions get sorted first by mergeAllWebhooks
-      expect(secondWrite).toMatchSnapshot()
+      // Clean round-trip: second write matches the first
+      expect(secondWrite).toEqual(firstWrite)
     })
   })
 

packages/app/src/cli/services/context/breakdown-extensions.ts

@@ -19,6 +19,7 @@ import {ExtensionSpecification} from '../../models/extensions/specification.js'
 import {rewriteConfiguration} from '../app/write-app-configuration-file.js'
 import {AppConfigurationUsedByCli} from '../../models/extensions/specifications/types/app_config.js'
 import {removeTrailingSlash} from '../../models/extensions/specifications/validation/common.js'
+import {mergeAllWebhooks} from '../../models/extensions/specifications/transform/app_config_webhook.js'
 import {throwUidMappingError} from '../../prompts/uid-mapping-error.js'
 import {deepCompare, deepDifference} from '@shopify/cli-kit/common/object'
 import {zod} from '@shopify/cli-kit/node/schema'
@@ -196,6 +197,15 @@ async function resolveRemoteConfigExtensionIdentifiersBreakdown(
       : app.configuration
   ) as CurrentAppConfiguration
 
+  // Normalize webhook subscriptions to canonical one-topic-per-subscription form for comparison.
+  // This ensures local (raw multi-topic) and remote (exploded single-topic) subscriptions are comparable.
+  if (baselineConfig?.webhooks?.subscriptions?.length) {
+    baselineConfig.webhooks.subscriptions = mergeAllWebhooks(baselineConfig.webhooks.subscriptions) ?? []
+  }
+  if (remoteConfig?.webhooks?.subscriptions?.length) {
+    remoteConfig.webhooks.subscriptions = mergeAllWebhooks(remoteConfig.webhooks.subscriptions) ?? []
+  }
+
   // modify relative path webhook subscriptions to include app url so client vs server diff checking is consistent
   if (baselineConfig?.webhooks?.subscriptions?.length) {
     baselineConfig.webhooks.subscriptions = baselineConfig.webhooks.subscriptions.map((subscription) => {