Decompose loader into composable stages with narrow interfaces

Replace the monolithic loadApp pipeline with composable stages:
- loadApp is now a thin wrapper: getAppConfigurationContext → loadAppFromContext
- loadAppFromContext takes narrow Project + ActiveConfig directly
- getAppConfigurationContext is discovery-only (no parsing/state construction)
- ReloadState replaces passing entire AppLinkedInterface through reloads
- AppLoader takes reloadState? instead of previousApp?
- link() returns {remoteApp, configFileName, configuration} (no state)
- linkedAppContext uses activeConfig directly, no AppConfigurationState

Remove dead code: AppConfigurationState, toAppConfigurationState,
loadAppConfigurationFromState, loadAppUsingConfigurationState,
loadAppConfiguration, getAppConfigurationState, getAppDirectory,
loadDotEnv, loadHiddenConfig, findWebConfigPaths, loadWebsForAppCreation.

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

Author: ryancbahan

packages/app/src/cli/commands/app/config/link.ts

@@ -34,7 +34,7 @@ export default class ConfigLink extends AppLinkedCommand {
       directory: flags.path,
       clientId: undefined,
       forceRelink: false,
-      userProvidedConfigName: result.state.configurationFileName,
+      userProvidedConfigName: result.configFileName,
     })
 
     return {app}

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

@@ -3,14 +3,12 @@ import {
   getAppConfigurationFileName,
   loadApp,
   loadOpaqueApp,
-  loadDotEnv,
   parseConfigurationObject,
   checkFolderIsValidApp,
   AppLoaderMode,
-  getAppConfigurationState,
+  getAppConfigurationContext,
   loadConfigForAppCreation,
   reloadApp,
-  loadHiddenConfig,
 } from './loader.js'
 import {parseHumanReadableError} from './error-parsing.js'
 import {App, AppConfiguration, AppInterface, AppLinkedInterface, AppSchema, WebConfigurationSchema} from './app.js'
@@ -33,7 +31,7 @@ import {
   PackageJson,
   pnpmWorkspaceFile,
 } from '@shopify/cli-kit/node/node-package-manager'
-import {inTemporaryDirectory, moveFile, mkdir, mkTmpDir, rmdir, writeFile, readFile} from '@shopify/cli-kit/node/fs'
+import {inTemporaryDirectory, moveFile, mkdir, mkTmpDir, rmdir, writeFile} from '@shopify/cli-kit/node/fs'
 import {joinPath, dirname, cwd, normalizePath} from '@shopify/cli-kit/node/path'
 import {platformAndArch} from '@shopify/cli-kit/node/os'
 import {outputContent, outputToken} from '@shopify/cli-kit/node/output'
@@ -2813,46 +2811,6 @@ describe('getAppConfigurationShorthand', () => {
   })
 })
 
-describe('loadDotEnv', () => {
-  test('it returns undefined if the env is missing', async () => {
-    await inTemporaryDirectory(async (tmp) => {
-      // When
-      const got = await loadDotEnv(tmp, joinPath(tmp, 'shopify.app.toml'))
-
-      // Then
-      expect(got).toBeUndefined()
-    })
-  })
-
-  test('it loads from the default env file', async () => {
-    await inTemporaryDirectory(async (tmp) => {
-      // Given
-      await writeFile(joinPath(tmp, '.env'), 'FOO="bar"')
-
-      // When
-      const got = await loadDotEnv(tmp, joinPath(tmp, 'shopify.app.toml'))
-
-      // Then
-      expect(got).toBeDefined()
-      expect(got!.variables.FOO).toEqual('bar')
-    })
-  })
-
-  test('it loads from the config specific env file', async () => {
-    await inTemporaryDirectory(async (tmp) => {
-      // Given
-      await writeFile(joinPath(tmp, '.env.staging'), 'FOO="bar"')
-
-      // When
-      const got = await loadDotEnv(tmp, joinPath(tmp, 'shopify.app.staging.toml'))
-
-      // Then
-      expect(got).toBeDefined()
-      expect(got!.variables.FOO).toEqual('bar')
-    })
-  })
-})
-
 describe('checkFolderIsValidApp', () => {
   test('throws an error if the folder does not contain a shopify.app.toml file', async () => {
     await inTemporaryDirectory(async (tmp) => {
@@ -3484,46 +3442,26 @@ describe('WebhooksSchema', () => {
   }
 })
 
-describe('getAppConfigurationState', () => {
+describe('getAppConfigurationContext', () => {
   test.each([
-    [
-      `client_id="abcdef"`,
-      {
-        basicConfiguration: {
-          client_id: 'abcdef',
-        },
-        isLinked: true,
-      },
-    ],
+    [`client_id="abcdef"`, {client_id: 'abcdef'}, true],
     [
       `client_id="abcdef"
       something_extra="keep"`,
-      {
-        basicConfiguration: {
-          client_id: 'abcdef',
-          something_extra: 'keep',
-        },
-        isLinked: true,
-      },
+      {client_id: 'abcdef', something_extra: 'keep'},
+      true,
     ],
-    [
-      `client_id=""`,
-      {
-        basicConfiguration: {
-          client_id: '',
-        },
-        isLinked: false,
-      },
-    ],
-  ])('loads from %s', async (content, resultShouldContain) => {
+    [`client_id=""`, {client_id: ''}, false],
+  ])('loads from %s', async (content, expectedContent, expectedIsLinked) => {
     await inTemporaryDirectory(async (tmpDir) => {
       const appConfigPath = joinPath(tmpDir, 'shopify.app.toml')
       const packageJsonPath = joinPath(tmpDir, 'package.json')
       await writeFile(appConfigPath, content)
       await writeFile(packageJsonPath, '{}')
 
-      const state = await getAppConfigurationState(tmpDir, undefined)
-      expect(state).toMatchObject(resultShouldContain)
+      const {activeConfig} = await getAppConfigurationContext(tmpDir, undefined)
+      expect(activeConfig.file.content).toMatchObject(expectedContent)
+      expect(activeConfig.isLinked).toBe(expectedIsLinked)
     })
   })
 
@@ -3535,10 +3473,10 @@ describe('getAppConfigurationState', () => {
       await writeFile(appConfigPath, content)
       await writeFile(packageJsonPath, '{}')
 
-      const result = await getAppConfigurationState(tmpDir, undefined)
+      const {activeConfig} = await getAppConfigurationContext(tmpDir, undefined)
 
-      expect(result.basicConfiguration.client_id).toBe('')
-      expect(result.isLinked).toBe(false)
+      expect(activeConfig.file.content.client_id).toBe('')
+      expect(activeConfig.isLinked).toBe(false)
     })
   })
 })
@@ -3683,6 +3621,7 @@ value = true
   })
 })
 
+<<<<<<< HEAD
 describe('loadHiddenConfig', () => {
   test('returns empty object if hidden config file does not exist', async () => {
     await inTemporaryDirectory(async (tmpDir) => {
@@ -3705,94 +3644,7 @@ describe('loadHiddenConfig', () => {
     })
   })
 
-  test('returns config for client_id if hidden config file exists', async () => {
-    await inTemporaryDirectory(async (tmpDir) => {
-      // Given
-      const configuration = {
-        client_id: '12345',
-      } as AppConfiguration
-      const hiddenConfigPath = joinPath(tmpDir, '.shopify', 'project.json')
-      await mkdir(dirname(hiddenConfigPath))
-      await writeFile(
-        hiddenConfigPath,
-        JSON.stringify({
-          '12345': {someKey: 'someValue'},
-          'other-id': {otherKey: 'otherValue'},
-        }),
-      )
-
-      // When
-      const got = await loadHiddenConfig(tmpDir, configuration)
-
-      // Then
-      expect(got).toEqual({someKey: 'someValue'})
-    })
-  })
-
-  test('returns empty object if client_id not found in existing hidden config', async () => {
-    await inTemporaryDirectory(async (tmpDir) => {
-      // Given
-      const configuration = {
-        client_id: 'not-found',
-      } as AppConfiguration
-      const hiddenConfigPath = joinPath(tmpDir, '.shopify', 'project.json')
-      await mkdir(dirname(hiddenConfigPath))
-      await writeFile(
-        hiddenConfigPath,
-        JSON.stringify({
-          'other-id': {someKey: 'someValue'},
-        }),
-      )
-
-      // When
-      const got = await loadHiddenConfig(tmpDir, configuration)
-
-      // Then
-      expect(got).toEqual({})
-    })
-  })
-
-  test('returns config if hidden config has an old format with just a dev_store_url', async () => {
-    await inTemporaryDirectory(async (tmpDir) => {
-      // Given
-      const configuration = {
-        client_id: 'not-found',
-      } as AppConfiguration
-      const hiddenConfigPath = joinPath(tmpDir, '.shopify', 'project.json')
-      await mkdir(dirname(hiddenConfigPath))
-      await writeFile(
-        hiddenConfigPath,
-        JSON.stringify({
-          dev_store_url: 'https://dev-store.myshopify.com',
-        }),
-      )
-
-      // When
-      const got = await loadHiddenConfig(tmpDir, configuration)
-
-      // Then
-      expect(got).toEqual({dev_store_url: 'https://dev-store.myshopify.com'})
-    })
-  })
-
-  test('returns empty object if hidden config file is invalid JSON', async () => {
-    await inTemporaryDirectory(async (tmpDir) => {
-      // Given
-      const configuration = {
-        client_id: '12345',
-      } as AppConfiguration
-      const hiddenConfigPath = joinPath(tmpDir, '.shopify', 'project.json')
-      await mkdir(dirname(hiddenConfigPath))
-      await writeFile(hiddenConfigPath, 'invalid json')
-
-      // When
-      const got = await loadHiddenConfig(tmpDir, configuration)
 
-      // Then
-      expect(got).toEqual({})
-    })
-  })
-})
 
 describe('loadOpaqueApp', () => {
   let specifications: ExtensionSpecification[]