Support single-subscription events modules when reading remote configuration

.changeset/events-config-link-shape-tolerance.md

@@ -0,0 +1,5 @@
+---
+'@shopify/app': patch
+---
+
+Support single-subscription events modules when reading remote app configuration

packages/app/src/cli/models/extensions/specifications/transform/app_config_events.test.ts

@@ -1,4 +1,5 @@
 import {transformToEventsConfig, transformFromEventsConfig} from './app_config_events.js'
+import {deepMergeObjects} from '@shopify/cli-kit/common/object'
 import {describe, expect, test} from 'vitest'
 
 describe('transformFromEventsConfig', () => {
@@ -115,6 +116,25 @@ describe('transformFromEventsConfig', () => {
     expect(result).toEqual(content)
   })
 
+  test('prepends application_url to a relative URI in a single subscription object', () => {
+    const content = {
+      events: {
+        api_version: '2024-01',
+        subscription: {topic: 'orders/create', uri: '/webhooks/orders', actions: ['create']},
+      },
+    }
+    const appConfiguration = {application_url: 'https://tunnel.example.com'}
+
+    const result = transformFromEventsConfig(content, appConfiguration)
+
+    expect(result).toEqual({
+      events: {
+        api_version: '2024-01',
+        subscription: {topic: 'orders/create', uri: 'https://tunnel.example.com/webhooks/orders', actions: ['create']},
+      },
+    })
+  })
+
   test('returns content as-is when events is undefined', () => {
     const content = {}
     const appConfiguration = {application_url: 'https://tunnel.example.com'}
@@ -192,4 +212,108 @@ describe('transformToEventsConfig', () => {
       },
     })
   })
+  test('strips the identifier from a single subscription object and returns it as a one-element array', () => {
+    const remoteContent = {
+      events: {
+        api_version: '2024-01',
+        subscription: {
+          topic: 'orders/create',
+          uri: 'https://example.com/webhook',
+          actions: ['create'],
+          handle: 'order-notifier',
+          identifier: 'id-1',
+        },
+      },
+    }
+
+    const result = transformToEventsConfig(remoteContent)
+
+    expect(result).toEqual({
+      events: {
+        api_version: '2024-01',
+        subscription: [
+          {
+            topic: 'orders/create',
+            uri: 'https://example.com/webhook',
+            actions: ['create'],
+            handle: 'order-notifier',
+          },
+        ],
+      },
+    })
+  })
+
+  test('merging multiple single-subscription modules accumulates one subscription array', () => {
+    const moduleOne = {
+      events: {
+        api_version: '2024-01',
+        subscription: {
+          topic: 'orders/create',
+          uri: 'https://example.com/a',
+          actions: ['create'],
+          handle: 'a',
+          identifier: 'id-a',
+        },
+      },
+    }
+    const moduleTwo = {
+      events: {
+        api_version: '2024-01',
+        subscription: {
+          topic: 'products/update',
+          uri: 'https://example.com/b',
+          actions: ['update'],
+          handle: 'b',
+          identifier: 'id-b',
+        },
+      },
+    }
+
+    const merged = deepMergeObjects(transformToEventsConfig(moduleOne), transformToEventsConfig(moduleTwo))
+
+    expect(merged).toEqual({
+      events: {
+        api_version: '2024-01',
+        subscription: [
+          {topic: 'orders/create', uri: 'https://example.com/a', actions: ['create'], handle: 'a'},
+          {topic: 'products/update', uri: 'https://example.com/b', actions: ['update'], handle: 'b'},
+        ],
+      },
+    })
+  })
+
+  test('merging a list-shape module with a single-subscription module accumulates all subscriptions', () => {
+    const listModule = {
+      events: {
+        api_version: '2024-01',
+        subscription: [
+          {topic: 'orders/create', uri: 'https://example.com/a', actions: ['create'], handle: 'a', identifier: 'id-a'},
+        ],
+      },
+    }
+    const singleModule = {
+      events: {
+        api_version: '2024-01',
+        subscription: {
+          topic: 'products/update',
+          uri: 'https://example.com/b',
+          actions: ['update'],
+          handle: 'b',
+          identifier: 'id-b',
+        },
+      },
+    }
+
+    const merged = deepMergeObjects(transformToEventsConfig(listModule), transformToEventsConfig(singleModule))
+
+    expect(merged).toEqual({
+      events: {
+        api_version: '2024-01',
+        subscription: [
+          {topic: 'orders/create', uri: 'https://example.com/a', actions: ['create'], handle: 'a'},
+          {topic: 'products/update', uri: 'https://example.com/b', actions: ['update'], handle: 'b'},
+        ],
+      },
+    })
+  })
 })

packages/app/src/cli/models/extensions/specifications/transform/app_config_events.ts

@@ -2,10 +2,15 @@ import {prependApplicationUrl} from '../validation/url_prepender.js'
 import {CurrentAppConfiguration} from '../../../app/app.js'
 import {getPathValue} from '@shopify/cli-kit/common/object'
 
+interface EventSubscription {
+  uri: string
+  [key: string]: unknown
+}
+
 interface EventsConfig {
   events?: {
     api_version?: string
-    subscription?: {uri: string; [key: string]: unknown}[]
+    subscription?: EventSubscription | EventSubscription[]
   }
 }
 
@@ -27,14 +32,17 @@ export function transformFromEventsConfig(content: object, appConfiguration?: ob
     appUrl = (appConfiguration as CurrentAppConfiguration)?.application_url
   }
 
+  const subscription = eventsConfig.events.subscription
+  const resolved = wrapSubscriptions(subscription).map((sub) => ({
+    ...sub,
+    uri: prependApplicationUrl(sub.uri, appUrl),
+  }))
+
   return {
     ...eventsConfig,
     events: {
       ...eventsConfig.events,
-      subscription: eventsConfig.events.subscription.map((sub) => ({
-        ...sub,
-        uri: prependApplicationUrl(sub.uri, appUrl),
-      })),
+      subscription: Array.isArray(subscription) ? resolved : resolved[0],
     },
   }
 }
@@ -44,18 +52,30 @@ export function transformFromEventsConfig(content: object, appConfiguration?: ob
  * Strips the server-managed 'identifier' field from subscriptions.
  */
 export function transformToEventsConfig(content: object) {
-  const eventsConfig = getPathValue(content, 'events') as {api_version: string; subscription: object[]}
+  const eventsConfig = getPathValue(content, 'events') as {
+    api_version: string
+    subscription: {identifier: string} | {identifier: string}[]
+  }
   const apiVersion = getPathValue(eventsConfig, 'api_version')
-  const subscription = getPathValue(eventsConfig, 'subscription') as {identifier: string}[]
+  const subscription = getPathValue<{identifier: string} | {identifier: string}[]>(eventsConfig, 'subscription')
 
-  // Server always includes identifier - strip it for local TOML
-  const cleanedSubscriptions = subscription?.map((sub) => {
-    const {identifier, ...rest} = sub
-    return rest
-  })
+  // Server always includes identifier - strip it for local TOML.
+  // Single-subscription modules are normalized to a one-element array so that
+  // merging multiple modules accumulates a single subscription list.
+  const cleanedSubscriptions =
+    subscription === undefined
+      ? undefined
+      : wrapSubscriptions(subscription).map((sub) => {
+          const {identifier, ...rest} = sub
+          return rest
+        })
 
   const events =
     (apiVersion ?? cleanedSubscriptions) ? {api_version: apiVersion, subscription: cleanedSubscriptions} : {}
 
   return {events}
 }
+
+function wrapSubscriptions<T>(subscription: T | T[]): T[] {
+  return Array.isArray(subscription) ? subscription : [subscription]
+}