feat(app-check): add Swift AppDelegate support for Expo SDK53+ (#8521)

Author: jeremyplt

packages/app-check/plugin/__tests__/fixtures/AppDelegate_sdk53.swift

@@ -0,0 +1,12 @@
+import Expo
+import React
+
+@UIApplicationMain
+class AppDelegate: ExpoAppDelegate {
+  override func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
+    // Initialize the factory
+    let factory = ExpoReactNativeFactory(delegate: delegate)
+    factory.startReactNative(withModuleName: "main", in: window, launchOptions: launchOptions)
+    return super.application(application, didFinishLaunchingWithOptions: launchOptions)
+  }
+}

packages/app-check/plugin/__tests__/iosPlugin.test.ts

@@ -4,7 +4,11 @@ import { beforeEach, describe, expect, it, jest } from '@jest/globals';
 import fs from 'fs/promises';
 import path from 'path';
 
-import { modifyAppDelegateAsync, modifyObjcAppDelegate } from '../src/ios/appDelegate';
+import {
+  modifyAppDelegateAsync,
+  modifyObjcAppDelegate,
+  modifySwiftAppDelegate,
+} from '../src/ios/appDelegate';
 
 describe('Config Plugin iOS Tests', function () {
   beforeEach(function () {
@@ -74,17 +78,52 @@ describe('Config Plugin iOS Tests', function () {
     );
   });
 
-  it("doesn't support Swift AppDelegate", async function () {
-    jest.spyOn(fs, 'writeFile').mockImplementation(async () => {});
+  it('supports Swift AppDelegate', async function () {
+    // Use MockedFunction to properly type the mock
+    const writeFileMock = jest
+      .spyOn(fs, 'writeFile')
+      .mockImplementation(async () => {}) as jest.MockedFunction<typeof fs.writeFile>;
+
+    const swiftContents = `import Expo
+import React
+
+@UIApplicationMain
+class AppDelegate: ExpoAppDelegate {
+  override func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
+    // Initialize the factory
+    let factory = ExpoReactNativeFactory(delegate: delegate)
+    factory.startReactNative(withModuleName: "main", in: window, launchOptions: launchOptions)
+    return super.application(application, didFinishLaunchingWithOptions: launchOptions)
+  }
+}`;
 
     const appDelegateFileInfo: AppDelegateProjectFile = {
-      path: '.',
+      path: '/app/ios/App/AppDelegate.swift',
       language: 'swift',
-      contents: 'some dummy content',
+      contents: swiftContents,
     };
 
-    await expect(modifyAppDelegateAsync(appDelegateFileInfo)).rejects.toThrow();
-    expect(fs.writeFile).not.toHaveBeenCalled();
+    await modifyAppDelegateAsync(appDelegateFileInfo);
+
+    // Check if writeFile was called
+    expect(writeFileMock).toHaveBeenCalled();
+
+    // Get the modified content with explicit string type assertion
+    const modifiedContents = writeFileMock.mock.calls[0][1] as string;
+
+    // Verify import was added
+    expect(modifiedContents).toContain('import RNFBAppCheck');
+
+    // Verify initialization code was added
+    expect(modifiedContents).toContain('RNFBAppCheckModule.sharedInstance()');
+
+    // Verify Firebase.configure() was added
+    expect(modifiedContents).toContain('FirebaseApp.configure()');
+
+    // Verify the code was added before startReactNative (with explicit type assertion)
+    const codeIndex = (modifiedContents as string).indexOf('RNFBAppCheckModule.sharedInstance()');
+    const startReactNativeIndex = (modifiedContents as string).indexOf('factory.startReactNative');
+    expect(codeIndex).toBeLessThan(startReactNativeIndex);
   });
 
   it('does not add the firebase import multiple times', async function () {
@@ -104,4 +143,30 @@ describe('Config Plugin iOS Tests', function () {
     expect(twiceModifiedAppDelegate).toContain(singleImport);
     expect(twiceModifiedAppDelegate).not.toContain(doubleImport);
   });
+
+  it('does not add the swift import multiple times', async function () {
+    const swiftContents = `import Expo
+import React
+
+@UIApplicationMain
+class AppDelegate: ExpoAppDelegate {
+  func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
+    let factory = ExpoReactNativeFactory(delegate: delegate)
+    factory.startReactNative(withModuleName: "main", in: window, launchOptions: launchOptions)
+    return super.application(application, didFinishLaunchingWithOptions: launchOptions)
+  }
+}`;
+
+    const onceModifiedContents = modifySwiftAppDelegate(swiftContents);
+    expect(onceModifiedContents).toContain('import RNFBAppCheck');
+
+    // Count occurrences of the import
+    const importCount = (onceModifiedContents.match(/import RNFBAppCheck/g) || []).length;
+    expect(importCount).toBe(1);
+
+    // Modify a second time and ensure imports aren't duplicated
+    const twiceModifiedContents = modifySwiftAppDelegate(onceModifiedContents);
+    const secondImportCount = (twiceModifiedContents.match(/import RNFBAppCheck/g) || []).length;
+    expect(secondImportCount).toBe(1);
+  });
 });

packages/app-check/plugin/src/ios/appDelegate.ts

@@ -68,16 +68,91 @@ export function modifyObjcAppDelegate(contents: string): string {
   }
 }
 
+export function modifySwiftAppDelegate(contents: string): string {
+  // Add imports for Swift
+  if (!contents.includes('import RNFBAppCheck')) {
+    // Try to add after FirebaseCore if it exists
+    if (contents.includes('import FirebaseCore')) {
+      contents = contents.replace(
+        /import FirebaseCore/g,
+        `import FirebaseCore
+import RNFBAppCheck`,
+      );
+    } else {
+      // Otherwise add after Expo
+      contents = contents.replace(
+        /import Expo/g,
+        `import Expo
+import RNFBAppCheck`,
+      );
+    }
+  }
+
+  // Check if App Check code is already added to avoid duplication
+  if (contents.includes('RNFBAppCheckModule.sharedInstance()')) {
+    return contents;
+  }
+
+  // Find the Firebase initialization end line to insert after
+  const firebaseLine = '// @generated end @react-native-firebase/app-didFinishLaunchingWithOptions';
+
+  if (contents.includes(firebaseLine)) {
+    // Insert right after Firebase initialization
+    return contents.replace(
+      firebaseLine,
+      `${firebaseLine}
+        FirebaseApp.configure()
+        RNFBAppCheckModule.sharedInstance()
+      `,
+    );
+  }
+
+  // If Firebase initialization block not found, add both Firebase and App Check initialization
+  // This is to make sure Firebase is initialized before App Check
+  const methodInvocationBlock = `FirebaseApp.configure()
+    RNFBAppCheckModule.sharedInstance()`;
+
+  const methodInvocationLineMatcher = /(?:factory\.startReactNative\()/;
+
+  if (!methodInvocationLineMatcher.test(contents)) {
+    WarningAggregator.addWarningIOS(
+      '@react-native-firebase/app-check',
+      'Unable to determine correct insertion point in AppDelegate.swift. Skipping App Check addition.',
+    );
+    return contents;
+  }
+
+  try {
+    return mergeContents({
+      tag: '@react-native-firebase/app-check',
+      src: contents,
+      newSrc: methodInvocationBlock,
+      anchor: methodInvocationLineMatcher,
+      offset: 0,
+      comment: '//',
+    }).contents;
+  } catch (_e) {
+    WarningAggregator.addWarningIOS(
+      '@react-native-firebase/app-check',
+      'Failed to insert App Check initialization code.',
+    );
+    return contents;
+  }
+}
+
 export async function modifyAppDelegateAsync(appDelegateFileInfo: AppDelegateProjectFile) {
   const { language, path, contents } = appDelegateFileInfo;
 
+  let newContents;
   if (['objc', 'objcpp'].includes(language)) {
-    const newContents = modifyObjcAppDelegate(contents);
-    await fs.promises.writeFile(path, newContents);
+    newContents = modifyObjcAppDelegate(contents);
+  } else if (language === 'swift') {
+    newContents = modifySwiftAppDelegate(contents);
   } else {
-    // TODO: Support Swift
     throw new Error(`Cannot add Firebase code to AppDelegate of language "${language}"`);
   }
+
+  await fs.promises.writeFile(path, newContents);
 }
 
 export const withFirebaseAppDelegate: ConfigPlugin = config => {