feat: updates configure to also write out iOS app ID files (#43)

packages/flutterfire_cli/lib/src/commands/config.dart

@@ -22,6 +22,7 @@ import '../common/platform.dart';
 import '../common/utils.dart';
 import '../firebase.dart' as firebase;
 import '../firebase/firebase_android_options.dart';
+import '../firebase/firebase_app_id_file.dart';
 import '../firebase/firebase_apple_options.dart';
 import '../firebase/firebase_configuration_file.dart';
 import '../firebase/firebase_options.dart';
@@ -107,6 +108,18 @@ class ConfigCommand extends FlutterFireCommand {
     return argResults!['out'] as String;
   }
 
+  String get appIDFilePath {
+    return 'firebase_app_id_file.json';
+  }
+
+  String get iosAppIDOutputFilePrefix {
+    return 'ios';
+  }
+
+  String get macosAppIDOutputFilePrefix {
+    return 'macos';
+  }
+
   Future<FirebaseProject> _promptCreateFirebaseProject() async {
     final newProjectId = promptInput(
       'Enter a project id for your new Firebase project (e.g. ${AnsiStyles.cyan('my-cool-project')})',
@@ -143,6 +156,7 @@ class ConfigCommand extends FlutterFireCommand {
     }
 
     List<FirebaseProject>? firebaseProjects;
+
     final fetchingProjectsSpinner = spinner(
       (done) {
         if (!done) {
@@ -157,6 +171,7 @@ class ConfigCommand extends FlutterFireCommand {
       },
     );
     firebaseProjects = await firebase.getProjects(account: accountEmail);
+
     fetchingProjectsSpinner.done();
     if (selectedProjectId != null) {
       return firebaseProjects.firstWhere(
@@ -271,15 +286,36 @@ class ConfigCommand extends FlutterFireCommand {
       );
     }
 
+    final futures = <Future>[];
+
     final configFile = FirebaseConfigurationFile(
       outputFilePath,
       androidOptions: androidOptions,
       iosOptions: iosOptions,
       macosOptions: macosOptions,
       webOptions: webOptions,
     );
+    futures.add(configFile.write());
+
+    if (iosOptions != null) {
+      final appIDFile = FirebaseAppIDFile(
+        iosAppIDOutputFilePrefix,
+        appIDFilePath,
+        iosOptions.appId,
+      );
+      futures.add(appIDFile.write());
+    }
+
+    if (macosOptions != null) {
+      final appIDFile = FirebaseAppIDFile(
+        macosAppIDOutputFilePrefix,
+        appIDFilePath,
+        macosOptions.appId,
+      );
+      futures.add(appIDFile.write());
+    }
 
-    await configFile.write();
+    await Future.wait<void>(futures);
 
     logger.stdout('');
     logger.stdout(

packages/flutterfire_cli/lib/src/common/exception.dart

@@ -63,6 +63,28 @@ class FirebaseOptionsAlreadyExistsException implements FlutterFireException {
   }
 }
 
+class FirebaseAppIDAlreadyExistsException implements FlutterFireException {
+  FirebaseAppIDAlreadyExistsException(this.filePath) : super();
+
+  final String filePath;
+
+  @override
+  String toString() {
+    return 'FirebaseAppIDAlreadyExistsException: Firebase app ID file ${AnsiStyles.cyan(filePath)} already exists.';
+  }
+}
+
+class PlatformDirectoryDoesNotExistException implements FlutterFireException {
+  PlatformDirectoryDoesNotExistException(this.filePath) : super();
+
+  final String filePath;
+
+  @override
+  String toString() {
+    return 'PlatformDirectoryDoesNotExistException: platform directory ${AnsiStyles.cyan(filePath)} does not exist. Please re-run after initializing this directory with Flutter.';
+  }
+}
+
 class FlutterPlatformNotSupportedException implements FlutterFireException {
   FlutterPlatformNotSupportedException(this.platform) : super();
 

packages/flutterfire_cli/lib/src/firebase/firebase_app_id_file.dart

@@ -0,0 +1,69 @@
+/*
+ * Copyright (c) 2016-present Invertase Limited & Contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this library except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+import 'dart:convert';
+import 'dart:io';
+
+import 'package:ansi_styles/ansi_styles.dart';
+import 'package:interact/interact.dart' as interact;
+import 'package:path/path.dart';
+
+import '../common/exception.dart';
+import '../common/utils.dart';
+
+class FirebaseAppIDFile {
+  FirebaseAppIDFile(this.outputDirectoryPath, this.fileName, this.appId);
+
+  final StringBuffer _stringBuffer = StringBuffer();
+
+  final String outputDirectoryPath;
+
+  final String fileName;
+
+  final String appId;
+
+  Future<void> write() async {
+    // ignore: avoid_slow_async_io
+    final directoryExists = await Directory(outputDirectoryPath).exists();
+    if (!directoryExists) {
+      throw PlatformDirectoryDoesNotExistException(outputDirectoryPath);
+    }
+    final appIDFilePath = joinAll([outputDirectoryPath, fileName]);
+    final outputFile = File(joinAll([Directory.current.path, appIDFilePath]));
+    if (outputFile.existsSync() && !isCI) {
+      final shouldOverwrite = interact.Confirm(
+        prompt:
+            'Generated FirebaseAppID file ${AnsiStyles.cyan(appIDFilePath)} already exists, do you want to override it?',
+        defaultValue: true,
+      ).interact();
+      if (!shouldOverwrite) {
+        throw FirebaseAppIDAlreadyExistsException(appIDFilePath);
+      }
+    }
+    _writeHeaderAndAppID(outputFile.path);
+    outputFile.writeAsStringSync(_stringBuffer.toString());
+  }
+
+  void _writeHeaderAndAppID(String outputFile) {
+    final fileData = {
+      'file_generated_by': 'FlutterFire CLI',
+      'purpose': 'FirebaseAppID for this Firebase app in this directory',
+      'GOOGLE_APP_ID': appId
+    };
+    _stringBuffer.write(json.encode(fileData));
+  }
+}