wip: Functions APIs and tests

packages/dart_firebase_admin/.firebaserc

@@ -0,0 +1,5 @@
+{
+  "projects": {
+    "default": "dart-firebase-admin"
+  }
+}

packages/dart_firebase_admin/.gitignore

@@ -1 +1,6 @@
-service-account-key.json
+service-account-key.json
+
+# Test functions artifacts
+test/functions/node_modules/
+test/functions/lib/
+test/functions/package-lock.json

packages/dart_firebase_admin/example/example_functions_ts/.eslintrc.js

@@ -0,0 +1,33 @@
+module.exports = {
+  root: true,
+  env: {
+    es6: true,
+    node: true,
+  },
+  extends: [
+    "eslint:recommended",
+    "plugin:import/errors",
+    "plugin:import/warnings",
+    "plugin:import/typescript",
+    "google",
+    "plugin:@typescript-eslint/recommended",
+  ],
+  parser: "@typescript-eslint/parser",
+  parserOptions: {
+    project: ["tsconfig.json", "tsconfig.dev.json"],
+    sourceType: "module",
+  },
+  ignorePatterns: [
+    "/lib/**/*", // Ignore built files.
+    "/generated/**/*", // Ignore generated files.
+  ],
+  plugins: [
+    "@typescript-eslint",
+    "import",
+  ],
+  rules: {
+    "quotes": ["error", "double"],
+    "import/no-unresolved": 0,
+    "indent": ["error", 2],
+  },
+};

packages/dart_firebase_admin/example/example_functions_ts/.gitignore

@@ -0,0 +1,11 @@
+# Compiled JavaScript files
+lib/**/*.js
+lib/**/*.js.map
+
+# TypeScript v1 declaration files
+typings/
+
+# Node.js dependency directory
+node_modules/
+*.local
+package-lock.json

packages/dart_firebase_admin/example/example_functions_ts/package.json

@@ -0,0 +1,31 @@
+{
+  "name": "functions",
+  "scripts": {
+    "lint": "eslint --ext .js,.ts .",
+    "build": "tsc",
+    "build:watch": "tsc --watch",
+    "serve": "npm run build && firebase emulators:start --only functions",
+    "shell": "npm run build && firebase functions:shell",
+    "start": "npm run shell",
+    "deploy": "firebase deploy --only functions",
+    "logs": "firebase functions:log"
+  },
+  "engines": {
+    "node": "22"
+  },
+  "main": "lib/index.js",
+  "dependencies": {
+    "firebase-admin": "^12.6.0",
+    "firebase-functions": "^6.0.1"
+  },
+  "devDependencies": {
+    "@typescript-eslint/eslint-plugin": "^5.12.0",
+    "@typescript-eslint/parser": "^5.12.0",
+    "eslint": "^8.9.0",
+    "eslint-config-google": "^0.14.0",
+    "eslint-plugin-import": "^2.25.4",
+    "firebase-functions-test": "^3.1.0",
+    "typescript": "^4.9.0"
+  },
+  "private": true
+}

packages/dart_firebase_admin/example/example_functions_ts/src/index.ts

@@ -0,0 +1,28 @@
+/**
+ * Import function triggers from their respective submodules:
+ *
+ * import {onCall} from "firebase-functions/v2/https";
+ * import {onDocumentWritten} from "firebase-functions/v2/firestore";
+ *
+ * See a full list of supported triggers at https://firebase.google.com/docs/functions
+ */
+
+import {onTaskDispatched} from "firebase-functions/v2/tasks";
+
+// Start writing functions
+// https://firebase.google.com/docs/functions/typescript
+
+export const helloWorld = onTaskDispatched(
+  {
+    retryConfig: {
+      maxAttempts: 5,
+      minBackoffSeconds: 60,
+    },
+    rateLimits: {
+      maxConcurrentDispatches: 6,
+    },
+  },
+  async (req) => {
+    console.log("Task received:", req.data);
+  }
+);

packages/dart_firebase_admin/example/example_functions_ts/tsconfig.dev.json

@@ -0,0 +1,5 @@
+{
+  "include": [
+    ".eslintrc.js"
+  ]
+}

packages/dart_firebase_admin/example/example_functions_ts/tsconfig.json

@@ -0,0 +1,17 @@
+{
+  "compilerOptions": {
+    "module": "NodeNext",
+    "esModuleInterop": true,
+    "moduleResolution": "nodenext",
+    "noImplicitReturns": true,
+    "noUnusedLocals": true,
+    "outDir": "lib",
+    "sourceMap": true,
+    "strict": true,
+    "target": "es2017"
+  },
+  "compileOnSave": true,
+  "include": [
+    "src"
+  ]
+}

packages/dart_firebase_admin/example/lib/main.dart

@@ -1,23 +1,34 @@
 import 'package:dart_firebase_admin/auth.dart';
 import 'package:dart_firebase_admin/dart_firebase_admin.dart';
 import 'package:dart_firebase_admin/firestore.dart';
+import 'package:dart_firebase_admin/functions.dart';
 import 'package:dart_firebase_admin/messaging.dart';
 
 Future<void> main() async {
   final admin = FirebaseApp.initializeApp();
-  await authExample(admin);
-  await firestoreExample(admin);
-  await projectConfigExample(admin);
+
+  // Uncomment to run auth example
+  // await authExample(admin);
+
+  // Uncomment to run firestore example
+  // await firestoreExample(admin);
+
+  // Uncomment to run project config example
+  // await projectConfigExample(admin);
 
   // Uncomment to run tenant example (requires Identity Platform upgrade)
   // await tenantExample(admin);
 
   // Uncomment to run messaging example (requires valid fcm token)
   // await messagingExample(admin);
 
+  // Uncomment to run functions example
+  // await functionsExample(admin);
+
   await admin.close();
 }
 
+// ignore: unreachable_from_main
 Future<void> authExample(FirebaseApp admin) async {
   print('\n### Auth Example ###\n');
 
@@ -47,6 +58,7 @@ Future<void> authExample(FirebaseApp admin) async {
   }
 }
 
+// ignore: unreachable_from_main
 Future<void> firestoreExample(FirebaseApp admin) async {
   print('\n### Firestore Example ###\n');
 
@@ -64,6 +76,7 @@ Future<void> firestoreExample(FirebaseApp admin) async {
   }
 }
 
+// ignore: unreachable_from_main
 Future<void> projectConfigExample(FirebaseApp admin) async {
   print('\n### Project Config Example ###\n');
 
@@ -379,3 +392,83 @@ Future<void> messagingExample(FirebaseApp admin) async {
     print('> Error sending platform-specific message: $e');
   }
 }
+
+/// Functions example prerequisites:
+/// 1) Run `npm run build` in `example_functions_ts` to generate `index.js`.
+/// 2) From the example directory root (with `firebase.json` and `.firebaserc`),
+///    start emulators with `firebase emulators:start`.
+/// 3) Run `dart_firebase_admin/packages/dart_firebase_admin/example/run_with_emulator.sh`.
+// ignore: unreachable_from_main
+Future<void> functionsExample(FirebaseApp admin) async {
+  print('\n### Functions Example ###\n');
+
+  final functions = Functions(admin);
+
+  // Get a task queue reference
+  // The function name should match an existing Cloud Function or queue name
+  final taskQueue = functions.taskQueue('helloWorld');
+
+  // Example 1: Enqueue a simple task
+  try {
+    print('> Enqueuing a simple task...\n');
+    await taskQueue.enqueue({
+      'userId': 'user-123',
+      'action': 'sendWelcomeEmail',
+      'timestamp': DateTime.now().toIso8601String(),
+    });
+    print('Task enqueued successfully!\n');
+  } on FirebaseFunctionsAdminException catch (e) {
+    print('> Functions error: ${e.code} - ${e.message}\n');
+  } catch (e) {
+    print('> Error enqueuing task: $e\n');
+  }
+
+  // Example 2: Enqueue with delay (1 hour from now)
+  try {
+    print('> Enqueuing a delayed task...\n');
+    await taskQueue.enqueue(
+      {'action': 'cleanupTempFiles'},
+      TaskOptions(schedule: DelayDelivery(3600)), // 1 hour delay
+    );
+    print('Delayed task enqueued successfully!\n');
+  } on FirebaseFunctionsAdminException catch (e) {
+    print('> Functions error: ${e.code} - ${e.message}\n');
+  }
+
+  // Example 3: Enqueue at specific time
+  try {
+    print('> Enqueuing a scheduled task...\n');
+    final scheduledTime = DateTime.now().add(const Duration(minutes: 30));
+    await taskQueue.enqueue({
+      'action': 'sendReport',
+    }, TaskOptions(schedule: AbsoluteDelivery(scheduledTime)));
+    print('Scheduled task enqueued for: $scheduledTime\n');
+  } on FirebaseFunctionsAdminException catch (e) {
+    print('> Functions error: ${e.code} - ${e.message}\n');
+  }
+
+  // Example 4: Enqueue with custom task ID (for deduplication)
+  try {
+    print('> Enqueuing a task with custom ID...\n');
+    await taskQueue.enqueue({
+      'orderId': 'order-456',
+      'action': 'processPayment',
+    }, TaskOptions(id: 'payment-order-456'));
+    print('Task with custom ID enqueued!\n');
+  } on FirebaseFunctionsAdminException catch (e) {
+    if (e.errorCode == FunctionsClientErrorCode.taskAlreadyExists) {
+      print('> Task with this ID already exists (deduplication)\n');
+    } else {
+      print('> Functions error: ${e.code} - ${e.message}\n');
+    }
+  }
+
+  // Example 5: Delete a task
+  try {
+    print('> Deleting task...\n');
+    await taskQueue.delete('payment-order-456');
+    print('Task deleted successfully!\n');
+  } on FirebaseFunctionsAdminException catch (e) {
+    print('> Functions error: ${e.code} - ${e.message}\n');
+  }
+}

packages/dart_firebase_admin/example/run_with_emulator.sh

@@ -3,6 +3,7 @@
 # Set environment variables for emulator
 export FIRESTORE_EMULATOR_HOST=localhost:8080
 export FIREBASE_AUTH_EMULATOR_HOST=localhost:9099
+export CLOUD_TASKS_EMULATOR_HOST=localhost:9499
 export GOOGLE_CLOUD_PROJECT=dart-firebase-admin
 
 # Run the example

packages/dart_firebase_admin/firebase.json

@@ -0,0 +1,32 @@
+{
+  "emulators": {
+    "auth": {
+      "port": 9099
+    },
+    "firestore": {
+      "port": 8080
+    },
+    "functions": {
+      "port": 5001
+    },
+    "tasks": {
+      "port": 9499
+    },
+    "ui": {
+      "enabled": true
+    },
+    "singleProjectMode": true
+  },
+  "functions": [
+    {
+      "source": "test/functions",
+      "codebase": "default",
+      "ignore": [
+        "node_modules",
+        ".git",
+        "firebase-debug.log",
+        "*.local"
+      ]
+    }
+  ]
+}

packages/dart_firebase_admin/lib/dart_firebase_admin.dart

@@ -7,4 +7,5 @@ export 'src/app.dart'
         EmulatorClient,
         Environment,
         FirebaseServiceType,
-        FirebaseService;
+        FirebaseService,
+        CloudTasksEmulatorClient;

packages/dart_firebase_admin/lib/functions.dart

@@ -0,0 +1 @@
+export 'src/functions/functions.dart';

packages/dart_firebase_admin/lib/src/app.dart

@@ -6,6 +6,7 @@ import 'dart:io';
 import 'dart:typed_data';
 
 import 'package:equatable/equatable.dart';
+// import 'package:googleapis/cloudfunctions/v2.dart' as auth4;
 import 'package:googleapis/identitytoolkit/v3.dart' as auth3;
 import 'package:googleapis_auth/auth_io.dart' as googleapis_auth;
 import 'package:googleapis_auth_utils/googleapis_auth_utils.dart'
@@ -16,6 +17,7 @@ import 'package:meta/meta.dart';
 import '../app_check.dart';
 import '../auth.dart';
 import '../firestore.dart';
+import '../functions.dart';
 import '../messaging.dart';
 import '../security_rules.dart';