Migrate channel spec to ChannelModule subclass (first proof of concept)

Phase 3b: First spec migrated to the new ExtensionInstance subclass pattern.

- Create ChannelModule extending ExtensionInstance directly with:
  - copy_files build config
  - include_assets client steps
  - contract-based deploy config
- Create channelDescriptor as a ModuleDescriptor
- Register descriptor in loadModuleRegistry()
- Remove channel from legacy spec list
- Wire moduleRegistry into loadAppFromContext pipeline

Channel extensions are now created via descriptor.createModule() instead
of new SpecificationBackedExtension() with a factory-generated spec.
513 model tests pass.

Author: isaacroldan

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

@@ -331,20 +331,22 @@ export async function loadAppFromContext<TModuleSpec extends ExtensionSpecificat
 
   // Build the module registry and merge remote spec values into it so
   // descriptors have up-to-date identity data from the platform API.
-  const moduleRegistry = loadModuleRegistry()
-  const remoteSpecsForMerge = specifications.map((spec) => ({
-    name: spec.externalName,
-    externalName: spec.externalName,
-    identifier: spec.identifier,
-    gated: false,
-    externalIdentifier: spec.externalIdentifier,
-    experience: spec.experience as 'extension' | 'configuration' | 'deprecated',
-    managementExperience: 'cli' as const,
-    registrationLimit: spec.registrationLimit,
-    uidStrategy: spec.uidStrategy,
-    surface: spec.surface,
-  }))
-  moduleRegistry.mergeRemoteSpecs(remoteSpecsForMerge)
+  const moduleRegistry = loadModuleRegistry?.() ?? new ModuleRegistry()
+  if (moduleRegistry.size > 0) {
+    const remoteSpecsForMerge = specifications.map((spec) => ({
+      name: spec.externalName,
+      externalName: spec.externalName,
+      identifier: spec.identifier,
+      gated: false,
+      externalIdentifier: spec.externalIdentifier,
+      experience: spec.experience as 'extension' | 'configuration' | 'deprecated',
+      managementExperience: 'cli' as const,
+      registrationLimit: spec.registrationLimit,
+      uidStrategy: spec.uidStrategy,
+      surface: spec.surface,
+    }))
+    moduleRegistry.mergeRemoteSpecs(remoteSpecsForMerge)
+  }
 
   const loadedConfiguration: ConfigurationLoaderResult<CurrentAppConfiguration, TModuleSpec> = {
     directory: project.directory,

packages/app/src/cli/models/extensions/load-specifications.ts

@@ -27,8 +27,8 @@ import themeSpec from './specifications/theme.js'
 import uiExtensionSpec from './specifications/ui_extension.js'
 import webPixelSpec from './specifications/web_pixel_extension.js'
 import editorExtensionCollectionSpecification from './specifications/editor_extension_collection.js'
-import channelSpecificationSpec from './specifications/channel.js'
 import adminSpecificationSpec from './specifications/admin.js'
+import {channelDescriptor} from './specifications/channel_module.js'
 
 const SORTED_CONFIGURATION_SPEC_IDENTIFIERS = [
   BrandingSpecIdentifier,
@@ -59,7 +59,7 @@ export async function loadLocalExtensionsSpecifications(): Promise<ExtensionSpec
  */
 export function loadModuleRegistry(): ModuleRegistry {
   const registry = new ModuleRegistry()
-  // Descriptors will be registered here as specs are migrated.
+  registry.register(channelDescriptor)
   return registry
 }
 
@@ -91,7 +91,6 @@ function loadSpecifications() {
     uiExtensionSpec,
     webPixelSpec,
     editorExtensionCollectionSpecification,
-    channelSpecificationSpec,
   ]
 
   return [...configModuleSpecs, ...moduleSpecs] as ExtensionSpecification[]

packages/app/src/cli/models/extensions/specifications/channel_module.ts

@@ -0,0 +1,80 @@
+import {ApplicationModule, ExtensionDeployConfigOptions} from '../application-module.js'
+import type {ExtensionFeature, BuildConfig} from '../application-module.js'
+import {ClientSteps} from '../../../services/build/client-steps.js'
+import {ModuleDescriptor} from '../module-descriptor.js'
+import {BaseConfigType, BaseSchema} from '../schemas.js'
+import {configWithoutFirstClassFields} from '../specification.js'
+import {loadLocalesConfig} from '../../../utilities/extensions/locales-configuration.js'
+import {joinPath} from '@shopify/cli-kit/node/path'
+import {zod} from '@shopify/cli-kit/node/schema'
+import {blocks} from '../../../constants.js'
+
+const SUBDIRECTORY_NAME = 'specifications'
+const FILE_EXTENSIONS = ['json', 'toml', 'yaml', 'yml', 'svg']
+
+export const ChannelModuleIdentifier = 'channel_config'
+
+class ChannelModule extends ApplicationModule {
+  appModuleFeatures(): ExtensionFeature[] {
+    return []
+  }
+
+  override get buildConfig(): BuildConfig {
+    return {
+      mode: 'copy_files',
+      filePatterns: FILE_EXTENSIONS.map((ext) => joinPath(SUBDIRECTORY_NAME, '**', `*.${ext}`)),
+    }
+  }
+
+  override get clientSteps(): ClientSteps {
+    return [
+      {
+        lifecycle: 'deploy',
+        steps: [
+          {
+            id: 'copy-files',
+            name: 'Copy Files',
+            type: 'include_assets',
+            config: {
+              inclusions: [
+                {
+                  type: 'pattern',
+                  baseDir: SUBDIRECTORY_NAME,
+                  destination: SUBDIRECTORY_NAME,
+                  include: FILE_EXTENSIONS.map((ext) => `**/*.${ext}`),
+                },
+              ],
+            },
+          },
+        ],
+      },
+    ]
+  }
+
+  override async deployConfig(_options: ExtensionDeployConfigOptions): Promise<Record<string, unknown> | undefined> {
+    let parsedConfig = configWithoutFirstClassFields(this.configuration)
+    if (this.appModuleFeatures().includes('localization')) {
+      const localization = await loadLocalesConfig(this.directory, this.identifier)
+      parsedConfig = {...parsedConfig, localization}
+    }
+    return parsedConfig
+  }
+}
+
+export const channelDescriptor: ModuleDescriptor = {
+  identifier: ChannelModuleIdentifier,
+  additionalIdentifiers: [],
+  externalIdentifier: `${ChannelModuleIdentifier}_external`,
+  externalName: 'Channel config',
+  partnersWebIdentifier: ChannelModuleIdentifier,
+  surface: 'test-surface',
+  registrationLimit: blocks.extensions.defaultRegistrationLimit,
+  experience: 'extension',
+  uidStrategy: 'single',
+  schema: zod.any({}) as unknown as typeof BaseSchema,
+  contributeToAppConfigurationSchema: (schema) => schema,
+  parseConfigurationObject: (configurationObject: object) => {
+    return {state: 'ok' as const, data: configurationObject as BaseConfigType, errors: undefined}
+  },
+  createModule: (options) => new ChannelModule(options),
+}